b Information on achievement of Data Quality Indicators is not available from field data. The references in the Data Quality Indicator table of the Quality Assurance Project Plan were generated in the laboratory for backup of published specifications. The procedures for establishing these values for non Criteria Pollutants were never intended to be " field verified." The actual procedure used to verify the values is written for the gaseous Criteria Pollutants ( SO2, NO2, O3) which are available in cylinders or from a generator. The gases are introduced into a cell in the measurement path to determine precision and accuracy. For mercury, vapor standards are not used by the testing group ( Opsis); the measurement work is performed with closed cells. A closed cell was not available for the field test; therefore, field verification of the literature value for measurement of Hg0 could not be performed. 88 SECTION 7 REFERENCES ASHRAE. 1981. American Society of Heating, Refrigerating and Air Conditioning Engineers ( 1981). ASHRAE Handbook 1981 Fundamentals, Atlanta, GA.

Chlorine Institute. 1999. Second Annual Report of the Chlorine Institute to the United States Environmental Protection Agency, Chlorine Institute, Washington, DC.

Cowherd, C., Jr., and J. S. Kinsey. 1986. Identification, Assessment, and Control of Fugitive Particulate Emissions. U. S. Environmental Protection Agency, Air and Energy Engineering Research Laboratory, Research Triangle Park, NC, August; EPA 600/ 8 86 023 ( NTIS PB86 230083).

Edner, H., G. W. Faris, A. Sunesson, and S. Svanberg. 1989. Atmospheric Atomic Mercury Monitoring Using Differential Lidar Techniques. Applied Optics, 28, 921 930.

EPA. 1984. U. S. Environmental Protection Agency. Method 14 Determination of Fluoride Emissions from Potroom Roof Monitors for Primary Aluminum Plants, 40 Code of Federal Regulations, Part 60, Appendix A, February 21, 1984.

EPA. 1999. U. S. Environmental Protection Agency. Compendium Method TO 16, Long Path Open Path Fourier Transform Infrared Monitoring of Atmospheric Gases, in " Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air," Center for Environmental Research Information, Office of Research and Development, Cincinnati, OH, January; EPA/ 625/ R 96/ 010b ( NTIS PB99 172355).

Ferrara, R., B. E. Maserti, H. Edner, P. Ragnarson, S. Svanberg, and E. Wallinder. 1992. Mercury Emissions into the Atmosphere from a Chlor Alkali Complex Measured with the Lidar Technique. Atmospheric Environment, 26A, 1253 1258.

Hunt, W. 1998. Personal communication from William Hunt, Director, Emissions Monitoring and Analysis Division, Office of Air Quality Planning and Standards, U. S. Environmental Protection Agency to Michael Palazzolo, ALCOA Corporation, Pittsburgh, PA, July 9, 1998.

Keating, M. H., D. Beauregard, W. G. Benjey, L. Driver, W. H. Maxwell, W. D. Peters, and A. A. Pope. 1997. Mercury Study Report to Congress, Volume II: An Inventory of Anthropogenic Mercury Emissions in the United States, U. S. Environmental Protection 89 Agency, Office of Air Quality Planning and Standards, Research Triangle Park, NC, December; EPA 452/ R 96 004 ( NTIS PB98 124746).

Kinsey, J. S., M. Landis, D. France, S. Lindberg, J. Nriagu, J. Swift, G. Ramsey, J. Pau, F. Anscombe, and N. Adams. 2000. Characterization of Mercury Emissions at a Chlor Alkali Plant, Quality Assurance Project Plan. U. S. Environmental Protection Agency, National Risk Management Research Laboratory, Research Triangle Park, NC, February 11, 2000.

Landis, M. S., R. K. Stevens, T. Crawford, D. France, C. Secrest, and S. Lindberg. 2000. Speciation of Mercury Emissions from a Chlor Alkali Plant, Presented at the AWMA International Symposium on the Measurement of Toxic and Related Air Pollutants, Research Triangle Park, NC, September 12 14, 2000.

Marks, P. J., and J. Davidson. 1972. EPA Test No. 72 PC 04, B. F. Goodrich Chemical Company Chlor Alkali Plant Calvert City, Kentucky; EPA Contract No. CPA 70 132, Task Order No. 3, U. S. Environmental Protection Agency, Office of Air Quality Planning and Standards, Research Triangle Park, NC, May.

Rosario, I. 2001. Personal communication from Iliam Rosario, Office of Air Quality Planning and Standards, U. S. Environmental Protection Agency, Research Triangle Park, NC, August 15, 2001.

Weston, Roy F. 1971. Georgia Pacific Chlor Alkali Plant, Bellingham, Washington; EPA Contract No. CPA 70 132, Task Order No. 2, U. S. Environmental Protection Agency, Office of Air Quality Planning and Standards, Research Triangle Park, NC. A i Appendix A Description of Buildings and Processes at the Olin Facility A ii ( Intentionally Blank) A 1 Olin CORPORATION AUGUSTA, GEORGIA November 4, 1995 30 YEAR CELEBRATION COMMUNITY OPEN HOUSE PLANT TOUR TOUR ROUTE  AT A GLANCE 1 OCEAN BUILDING This building contains the equipment we use to respond to product emergencies that occur outside the plant. The acronym OCEAN stands for Olin Chemical Emergency Action Network. We have a trained team that will respond to a product emergency 24 hours/ day, 7 days/ week. If you desire, as soon as we finish our tour, you will be able to see the OCEAN trailer, which is set up in front of the plant in the parking lot. You will be able to view our emergency equipment.

2 ANODE SHOP This shop contains the equipment used to rebuild worn or damaged anodes that have been removed from the cells. The rebuilt anodes are then placed in stock and are reinstalled in another cell at a later date.

The anode is constructed of titanium metal that is coated with a thin precious metal coating. The coating will wear off in time and will eventually have to be replaced.

3 SODIUM HYDROSULFITE AREA ( Reductone ® and Hydrolin ® )

 Sodium Hydrosulfite loading and storage Sodium Hydrosulfite is stored in six insulated fiberglass tanks. It must be kept cool since it will decompose when it gets too warm. It is stored at a slightly stronger concentration than required by our customers and is diluted to proper specifications as it is loaded into insulated trailers through the piping on the loading stations. 135,000 gallons of material can be stored in these tanks.

 Sodium Hydrosulfite Refrigeration The Sodium Hydrosulfite reaction is exothermic  it gives off heat. This heat must be removed from the process. The major portion of the heat removal is accomplished using the two large Carrier Corporation refrigeration units housed in this building. A 2  Sodium Hydrosulfite Reactors The Sodium Hydrosulfite reactors are sophisticated mixers. They take in water, sulfur dioxide, caustic and sodium amalgam to produce a solution of sodium hydrosulfite. The operating parameters  acidity concentrations and mixing rates  must be carefully controlled to get the proper product quality. Computers help control this operation using software designed by Olin Technical Center Engineers.

4 FIRE HOSE STATION The small red building located on the side of the roadway contains fire hoses and other fire fighting equipment. These stations are located throughout the plant.

5 SAFETY SHOWER Also, located throughout the plant are many safety showers and eye wash stations. In the event an employee is exposed to acid, caustic, or other chemicals, a safety shower is always close by so the employee can quickly turn on the shower and flush away the dangerous material.

6 MAIN CONTROL ROOM This control room has equipment used to monitor all major plant processes. The front panel houses the equipment which measures and controls the amount of DC electrical power applied to the cells. The back panel contains instrumentation to monitor and control most of the major processes in the plant, such as tank levels, pH measurements, line pressures, etc.

7 AUTOMATIC ANODE ADJUSTING SYSTEM This computer controlled system continuously scans all sixty cells and automatically adjusts the anodes in each cell to optimize the operation of each. By doing so, the amount of electrical power needed to produce a given amount of product is greatly reduced and the life of the anodes is greatly extended since the computer can make this adjustment far more accurately than humans can.

8 CELL ROOM The cell room is the heart of our process. Here up to 160,000 amps of DC electricity pass through the 60 electrolytic cells. In the cell, brine ( salt water) is electrolytically reduced to sodium and chlorine. The wet chlorine gas from the cells flows through a drying system to remove all the water from it and then travels on to the compressor building. The sodium combines with mercury and flows to the decomposer. In the decomposer, the sodium reacts with water and forms sodium hydroxide ( caustic). Caustic is pumped through cooling and filtration equipment and then is transferred to product storage. A by product from the decomposer is hydrogen gas. It passes through coolers and then on to blowers. It is burned in our boilers for steam generation. It is also used for production of hydrochloric acid and it is sold to Sunox Corporation. A 3 9 BRINE DECHLORINATION In this area, the residual chlorine left in the spent brine leaving the cells is removed. This is accomplished by passing the brine through two tanks that are kept under a high vacuum. The vacuum " boils" the chlorine gas out of the brine stream. The chlorine is recovered and the dechlorinated brine is pumped to the CP Salt Tank where it picks up a renewed supply of salt prior to beginning its return trip to the cells.

10 HYDROGEN BLOWERS Hydrogen is taken from the decomposers and passes through coolers that are cooled with chilled water. The cooling process removed most of the heat and mercury. The mercury is returned to the process. Hydrogen is then compressed using one or both blowers and sent to the boiler house where it is used as fuel and is also sent to other users.

11 AC POWER DISTRIBUTION Georgia Power provides our electrical power. Incoming voltage is 115,000 volts. Here we step it down to 13,800 volts, rectify part of it for the cell room use and distribute the remaining for usage throughout the plant at various voltages ( 2400, 480, 120).

12 BRINE FILTERS This is the first stage of brine purification. Fourteen brine filters are used to filter impurities from the brine. Each filter is independent of all others and must be removed from service periodically and backwashed for cleaning. The dirty backwashed brine is then collected in a tank, cleaned and recycled in the filter backwash system.

13 BRINE SETTLER The 480,000 gallon brine settler tank is used to settle out insoluble sludge in the brine. The sludge is flushed out the bottom of the settler.

14 PURASIV ® UNITS Hydrogen is a by product of the chlor/ alkali process and it is contaminated with small quantities of mercury. The mercury concentration must be further reduced before the hydrogen can be used. This is accomplished by passing the hydrogen through packed carbon beds, which absorb mercury. Absorbers polish and further remove mercury before the hydrogen is sent to our HCl plants.

15 BOILER HOUSE The steam generation plant consists of two separate boilers  each capable of producing 15,000 pounds of steam per hour at 250 pounds per square inch of pressure. They are normally fired with hydrogen. They can operate on natural gas, if necessary.

The steam is used throughout the plant for various purposes, such as brine dechlorination, brine heating, steam tracing of lines and heating certain tanks. A 4 16 SECONDARY TREATMENT All liquid waste streams contaminated with mercury must be cleaned before allowing them to proceed into our waste treatment system. On the average, the concentration of mercury in these wastes is reduced to less than 50 parts per billion of the discharged solution.

17 DECOMPOSER REPAIR BUILDING The Decomposer Repair Building holds equipment to rebuild and repack cell room decomposers. The decomposer is filled with graphite pellets which aid in creating the sodium hydroxide solution.

18 SUNOX CORPORATION The Sunox Corporation is one of Olin's customers. They purchase hydrogen gas from Olin. It is delivered to them through the pipeline along the side of the roadway. They receive and compress the hydrogen gas and load it into the trailers parked at the loading stations. The hydrogen is then shipped to customers in Augusta and throughout the Southeast.

19 INSTRUMENT AND ELECTRICAL SHOP This shop is equipped with test equipment and tools required to repair and troubleshoot the electrical equipment and the large number of instruments needed to keep the Augusta Plant operating efficiently.

20 COOLING TOWERS These large cooling towers are one of the ways Olin reduces water consumption. The plant uses about 6000 gallons per minute of water to remove heat from the process by pumping the water through various heat exchangers. The hot water is then recycled back to the cooling towers where evaporation cools the water so it can be used again.

21 PLANT EFFLUENT SYSTEM Waste water streams are collected throughout the plant in the process sewer system. This is the covered concrete ditch running through the center of the plant. Also, all rainwater runoff is collected. All of this water is monitored for pH, mercury, and chlorine content before it is released. If the streams are not acceptable, they are treated in the large tanks you see beside the road before the water is discharged to the Savannah River through a monitored and regulated national pollutant discharge elimination system.

22 GROUND WATER FILTERS The square filters beside the roadway are used to treat the groundwater from shallow wells around the plant. Here rainwater that has collected underground is pumped to the surface, checked for pH and mercury content, treated if necessary and released. A 5 23 CP SALT STORAGE TANK The CP salt is received in 100 ton hopper cars from Olin's diaphragm cell plant in McIntosh, Alabama. It is pumped from the hopper cars into the CP sale storage tank, from which is it pumped to the cell building.

Spent brine returns here from the cell room after it has been stripped of its salt in the cells. The depleted brine flows into the " diplegs" where it is resaturated before it is sent to the filters on its way back to the cells.

The Brine Saturation System has been retired for several years but can be reactivated if needed. It serves the same function as the CP salt tank.

24 RAILROAD YARD A significant portion of raw materials and finished product is handled by rail. We have six tracks in the plant designed and laid out so that shuffling of cars is possible. Each track serves its own purpose with track # 3 being the outward product shipment track. Southern Railway makes one switch daily. We perform other switching using one of our two Trackmobiles.

25 CHLORINE LOADING AND STORAGE Liquid chlorine may be loaded directly from the process into rail cars at loading stations # 1 & # 2 or stored in one of four chlorine storage tanks. Stored chlorine will be later loaded into railcars or shipped to customers through a pipeline.

26 INDUSTRIAL FILTER The dirty backwash brine from the brine filters is pumped through the industrial filter where it is cleaned up and recycled. The industrial filter must be cleaned daily after brine filter backwashing is completed and the sludge has been removed.

27 HYPO TANKS AND BLEACH SYSTEM In these tanks we create a weak caustic solution. This solution reacts with chlorine to form sodium hypochlorite ( hypo). During process upsets, this system will keep us from emitting chlorine to the atmosphere. It acts as a " scrubber" to remove chlorine from the process. Chlorine gas from the process can also be added to the caustic solution to increase the amount of hypo produced. The hypo is then sold as bleach. The hypo is similar to the material you purchase at the store under the trade name Clorox ® Bleach, but we manufacture a much stronger solution.

28 HYDROCHLORIC ACID PLANTS The original hydrochloric acid plant was built in 1982 to supply approximately 3 tons per day of acid to treat the brine system. Starting in 1983 some of the acid was sold to customers. Various modifications and additions to the basic equipment have been made over the years so that today the original burner system produces 30 tons per day of A 6 hydrochloric acid. In 1992, a near duplicate unit was added to the west, giving us an additional 30 tons per day capacity.

The acid is made by burning hydrogen and chlorine together in a furnace. The resulting HCl vapors are then absorbed into purified water to form a 37% acid solution. The acid is then piped to the large white storage tanks, where it is stored until it is shipped to customers in either tank trucks or railcars.

29 COMPRESSION AND LIQUEFACTION Chlorine gas is pulled from the cells by two banks of compressors located in this building and pushed through two liquefiers where the chlorine gas is condensed into a liquid. From there, it proceeds to the loading and storage area. The liquefiers condense about 99% of all the chlorine gas entering them. The remaining 1% is either absorbed into the inlet brine stream or sent to the hypo system.

The compressor building also houses the plant air compressors. They provide dry, compressed air for various uses in the plant. This system consists of two main plant air compressors, two high pressure booster compressors, one instrument air compressor and one back up diesel powered air compressor.

30 CAUSTIC AREA There are two main caustic storage tanks  each capable of holding 250,000 gallons ( 800 tons) of caustic soda. The caustic is pumped from here into tank cars or tank trucks for shipment to our customers.

The two tall, narrow tanks are caustic day tanks and are dedicated to service for Federal Paper Board. Caustic is pumped to Federal Paper from these tanks through a 7,000 foot long pipeline.

31 MAINTENANCE SHOP AND WAREHOUSE Most plant equipment repairs are handled in our own shop. It is equipped with tools, lathes and other machinery that enable us to accomplish this. It is made up of three departments  mechanical, instrumentation and electrical. Very little maintenance work is done outside of the plant.

Our warehouse, situated in the center of the building, provides ready access to most materials and supplies necessary for continuous plant operations.

32 ENGINEERING The plant has a technical staff which provides project and technical support for the plant. We have the ability to generate computer drawings ( CAD) and manual drawings. Plant drawings are stored in this area.

33 QUALITY CONTROL LABORATORY A 7 The laboratory responsible for the Quality Assurance of all of our outbound products and inbound raw materials. The Lab also ensures we are in compliance with the parameters of various plant effluents. In addition, the Lab furnishes the plant with analyses of various streams in the process in order to monitor equipment performance and minimize downtime. The Augusta Plant is an ISO 9002 registered facility.

34 DATA PROCESSING The plant has its own computer network ( LAN) and can also communicate with other Olin plants ( WAN). The networks are administered from this area.

35 MEDICAL The plant has a medical department staffed with a Certified Occupational Health Nurse. This area is equipped to handle on site emergencies as well as routine physicals, exams, etc.

REMARKS This concludes your tour of the Augusta Plant. Please return your safety gear to the boxes provided. Please return your copy of the tour script if you don't intend to keep it for future reference. If you are interested in seeing a further demonstration of the types of equipment we have on hand to respond to an outside emergency, we encourage you to visit the OCEAN trailer that is set up in the parking lot. If it is not your wish to visit the OCEAN trailer, join the other visitors in the tent area at this time. Thank you for visiting our plant and participating in our tour. B i Appendix B FTIR Spectral Analyses Conducted by ManTech, Inc. ( Jeff Childers) B ii ( Intentionally Blank) B 1 September 5, 2003 To: E. Hunter Daughtrey, Jr., Area Supervisor From: Jeffrey W. Childers, Principal Scientist Subject: WA IV 119   FTIR Data Interpretation Support 1.0 Background The Air Pollution Prevention and Control Division ( APPCD) participated in a major field experiment that was conducted in February of this year to characterize the mercury emissions from a chlor alkali plant in Augusta, GA. A tracer gas,

SF 6, was released at a controlled rate on the cell building floor to determine the total volumetric air flow from the roof vent of the building. One method used to determine the concentration of SF 6 emitted from the roof vent was open path Fourier transform infrared ( OP/ FTIR) spectrometry. Approximately 3000 OP/ FTIR spectra were obtained over a 10 day monitoring period. A subset of these data containing 305 spectra was analyzed under this work assignment.

The primary objective of this Work Assignment was to provide technical support to the APPCD for the interpretation, analysis, and quality control ( QC) of OP/ FTIR spectra data collected during the field test at the chlor alkali plant.

ManTech staff applied QC procedures developed under previous Work Assignments to NERL to the spectral data collected during the Augusta field study. These procedures are described in the FT IR Open Path Monitoring Guidance Document1 and Compendium Method TO 16   Long Path Open Path Fourier Transform Infrared Monitoring of Atmospheric Gases. 2 Additional B 2 guidance and operating procedures are given in an ASTM guide3 and standard practice. 4 The QC and data interpretation procedures applied to the OP/ FTIR data collected at the chlor alkali plant included:

Inspection of the single beam spectra for evidence of detector saturation or excessive stray light;

Measurement of the signal strength over time and the relative signal intensities in different spectral regions;

Estimation of the random baseline noise between successive data files over different spectral regions;

Development of a synthetic background spectrum;

Examination of the range of absorbance values exhibited by the SF 6 spectral features;

Identification of any interfering species;

Generation of relevant reference spectra from the HITRAN data base;

Inspection of the absorbance files for wavenumber shifts and changes in resolution;

Development and evaluation of an analysis method;

Comparison of the concentration values generated by the automated multivariate data analysis method to the manual comparison method or advanced nonlinear algorithms; and

Development of relevant control charts. B 3 2.0 Results and Discussion 2.1 Inspection of the Single beam Spectra for Evidence of Detector Saturation or Excessive Stray Light Two steps that should be completed during the initial instrument setup before data are collected include determining the distance at which the detector becomes saturated and measuring the signal due to internal stray light. Apparently, neither of these two steps was done during this study. The ramifications of this oversight on the accuracy of the reported concentration data are discussed below.

2.1.1 Determining the Distance to Detector Saturation The distance at which the detector becomes saturated determines the minimum pathlength over which quantitative data can be obtained with that particular instrument configuration. A procedure for determining this distance in given in Section 3.3 of the FT IR Open Path Monitoring Guidance Document. Evidence of detector saturation indicates that the detector is not responding linearly to changes in the incident light intensity and, therefore, will not respond linearly to changes in concentration of the gases along the path. Detector saturation causes errors in how the interferogram is sampled.

These errors can result in aliasing or folding of spectral features outside the normal sampling frequency range into the recorded spectrum. 5 This effect gives rise to abnormal shapes in the single beam spectrum and the appearance of non physical energy in spectral regions where there is no real spectral information. Because this anomalous information becomes part of the recorded interferogram, there is no way to compensate for the errors in the photometric accuracy due to detector saturation.

Once the OP/ FTIR system is set up along the desired monitoring pathlength, a singlebeam spectrum should be obtained. This spectrum should be inspected in the wave number region below the detector cutoff frequency. For most MCT detectors commonly B 4 used in OP/ FTIR applications, this cutoff frequency occurs between 650 and 700 cm 1.

The instrument response in this wavenumber region should be flat and at the baseline.

An elevated baseline in this region is due to non physical energy and indicates that the detector is saturated. If an elevated baseline is observed in this region of the single beam spectrum, the operator has three choices:

Increase the monitoring pathlength until the instrument response is flat and at the baseline in this region;

Place a wire mesh screen in the modulated, collimated IR beam to attenuate the signal intensity; or

Rotate the retroreflector to reduce the signal intensity.

A representative single beam spectrum from the Augusta field study is shown in Figure 1. This spectrum exhibits evidence of nonphysical energy in spectral regions that should be flat and at the baseline, including those below the detector cutoff frequency and in the totally opaque spectral regions between 1400 and 1800 cm 1 and 3600 and 3900 cm

1. This spectrum also exhibits an unusual curvature in the baseline in the 2550 to 2850

cm 1 region. As a comparison, a single beam spectrum collected in Research Triangle Park ( RTP), NC, with an ETG OP/ FTIR system over a 414 m total path is shown in Figure 2. The spectrum collected in RTP over a longer pathlength exhibits a flat baseline below the detector cutoff frequency and a steadily decreasing baseline from 2400 to 3250 cm 1.

All of the 305 spectra examined in the subset of data collected during the Augusta study exhibit evidence of detector saturation. Because of this observation, the accuracy of the concentration values reported from this data set is suspect and there is no way to assess errors in these measurements. In addition to errors in the absolute concentration measurements, changes in relative concentrations from one spectrum to another are most likely nonlinear and cannot be quoted with any certainty. B 5 2.1.2 Measuring the Signal Due to Internal Stray Light Single beam spectra recorded with an OP/ FTIR monitor can exhibit a non zero response in wavenumber regions in which the atmosphere is totally opaque. If the detector has been determined to be responding linearly to changes in the incident IR intensity, this non zero response can be attributed to internal stray light in monostatic instruments that use a single telescope to transmit and receive the IR beam. The presence of internal stray light causes errors in the photometric accuracy, and ultimately, errors in the reported concentration values. The effects of stray light on photometric accuracy are illustrated in Section 3.5 of the FT IR Open Path Monitoring Guidance Document. If uncorrected, the presence of stray light results in errors in the concentration measurements approximately equal to the percentage that the stray light contributes to the total signal.

Evidence of internal stray light is observed in the single beam spectrum collected at RTP in the CO 2 absorption region between 2300 and 2380 cm 1 ( see Figure 2). The strong CO 2 absorption bands in this region should extend completely to the baseline.

However, in this case, the presence of internal stray light causes the apparent baseline to be elevated. In this particular instrument, stray light contributed to approximately 6% of the total signal. No evidence of stray light can be observed in the single beam spectra collected during the Augusta study ( see Figure 1). However, the severe nonlinearity exhibited by these spectra prevents observation of the presence of stray light. A singlebeam spectrum of the internal stray light was not supplied with this data set. Therefore,

the effect of stray light on the data collected during the Augusta study cannot be determined. If stray light does contribute to the total signal in these spectra, the reported concentration values would contain errors proportional to the amount of stray light.

2.2 Measurement of the Signal Strength over Time and the Relative Signal Intensities at Different Spectral Regions B 6 The magnitude of the signal strength is indicative of the performance of the instrument, i. e., the output of the source or response of the detector, and the alignment of the transmitting/ receiving telescope and the retroreflector. The relative signal strength over different spectral regions is also indicative of the instrument performance and is influenced, among other factors, by the internal alignment of the interferometer. For example, if the interferometer is misaligned, the signal strength in the high wavenumber region will be relatively low.

The signal strengths at 985, 2500, and 4400 cm 1 were measured in the subset of 305 single beam spectra collected during the Augusta study. The signal strength at 985 cm 1 is reported directly, whereas the signal strengths at 2500 and 4400 cm 1 are ratioed to that at 985 cm 1 to determine the relative signal strength in the single beam spectra. Plots of the signal strength at 985 cm 1 and the relative signal strengths at 2500 and 4400 cm 1 for the single beam spectra in this subset are given in Figures 3   5.

The signal strength at 985 cm 1 over time is shown in Figure 3. This signal strength in arbitrary units ranged from 67.22 to 69.96 with a mean and standard deviation of 68.41 ± 0.59, for a relative standard deviation of 0.86%. The signal strength at 2500 cm 1 relative to that at 985 cm 1 ranged from a ratio of 0.832 to 0.854, with a mean and standard deviation of 0.842 ± 0.005 and a relative standard deviation of 0.59% ( see Figure 4). The signal strength at 4400 cm 1 relative to that at 985 cm 1 ranged from a ratio of 0.193 to 0.210, with a mean and standard deviation of 0.201 ± 0.004 and a relative standard deviation of 2.0 % ( see Figure 5).

The overall signal strength as measured in the single beam spectra at 985 cm 1 and the relative signal strengths measured at 2500 and 4400 cm 1 were nearly constant throughout the monitoring period represented by the 305 spectra analyzed in this subset of spectra from the Augusta study. These results indicate that no significant changes in the instrument performance or alignment occurred during this time period. B 7 2.3 Estimation of the Random Baseline Noise Between Successive Data Files over Different Spectral Regions Another indicator of instrument performance is the random baseline noise. This noise is measured as the root mean square ( RMS) deviation between successive single beam spectra collected sequentially during a monitoring period. To make this measurement, a series of absorption spectra was created from the subset of single beam spectra by using the preceding single beam spectrum as the background spectrum. For example, spectrum # d0224302 was used as the background spectrum for single beam spectrum # d0224303,

and so on. The RMS deviation was measured between 958 and 1008 cm 1, 2480 and 2530 cm 1, and 4375 and 4425 cm 1 and is reported in absorbance units. The random baseline noise measurements from the subset of single beam field spectra over time are given in Figures 6   8.

The random baseline noise between 958 and 1008 cm 1 ranged from 0.111 × 10 3 to 0.405 × 10 3 absorbance units, with a mean and standard deviation of 0.217 × 10 3 ± 0.053 × 10 3 ( see Figure 6). The random baseline noise between 2480 and 2530 cm 1 ranged from 0.037 × 10 3 to 0.073 × 10 3 absorbance units, with a mean and standard deviation of 0.056 × 10 3 ± 0.006 × 10 3 ( see Figure 7). The random baseline noise between 4375 and 4425 cm 1 ranged from 0.179 × 10 3 to 0.368 × 10 3 absorbance units, with a mean and standard deviation of 0.255 × 10 3 ± 0.029 × 10 3 ( see Figure 8).

Although there was some variability in the random baseline noise measurements ( the relative standard deviations for these measurements ranged from 11 to 24%) there were no obvious outliers in these data. The RMS noise levels in each spectral region were within the ranges expected for this type of instrument.

2.4 Development of a Synthetic Background Spectrum B 8 Three methods were used to generate background ( I 0) spectra so that the single beam field spectra could be converted to absorbance files. One method used a field spectrum collected at the end of the monitoring period that did not contain any spectral features due to SF 6. This method is similar to using an upwind background spectrum as described in Section 4.3 of the FT IR Open Path Monitoring Guidance Document. File # d0224306 was used for these purposes. With this method, the spectral features of the atmospheric gases and the instrument response essentially cancel out, leaving only the absorption features due to SF 6. When this is the case, quantitative data can only be obtained for the released tracer gas. The remaining absorption features of the atmospheric gases represent the difference between the concentrations in the other field spectra relative to those in spectrum # d0224306.

The second method used to generate an I 0 spectrum was to create a synthetic background spectrum from a representative field spectrum. File # d0224306 was again used for this purpose. A synthetic background spectrum was created from this file using the method described in Section 4.2 of the FT IR Open Path Monitoring Guidance Document. This synthetic background spectrum was created from 650 to 4500 cm 1 so that the entire spectrum could be analyzed for the target gas and other atmospheric gases.

The third method used to generate an I 0 spectrum fitted a series of segmented polynomial curves to each single beam spectrum as part of an automated analysis method using an innovative nonlinear algorithm. 6 No differences were found in the reported concentrations of SF 6 in the absorbance files created by using either file # d0224306 as the background spectrum or the synthetic background spectrum. The I 0 spectrum generated by the nonlinear algorithm was used only during the nonlinear analyses and was not used to generate absorbance files for subsequent analysis by another method. All of the concentration data reported from the B 9 Classical Least Squares ( CLS) analyses were computed from absorbance files created by using a synthetic background spectrum.

2.5 Examination of the Range of Absorbance Values Exhibited by the SF 6 Spectral Features The tracer gas SF 6 has a relatively high absorption coefficient at the peak maximum at approximately 948 cm 1. Because of the inherent nonlinear response of an OP/ FTIR system over a wide range of absorbance values, it is imperative to determine the range of absorbance values exhibited in the field spectra. The tracer gas was not detected in all of the field spectra in this subset. For those spectra in which SF 6 was not detected, the net absorbance at 948 cm 1 was approximately 0.02 absorbance units. This positive value was due to a small water vapor absorption band. The minimum net absorbance at 948 cm 1 in those spectra that did exhibit a detectable quantity of SF 6 was 0.145 absorbance units. The maximum net absorbance for SF 6 ( 0.185) was found for file # d0224291. The concentration of SF 6 found in this file exhibited a sharp increase relative to the concentrations in the other files and did not fit the trend exhibited by the preceding data files. For those spectra that did fit the overall trend, the maximum net absorbance was 0.164 ( file # d0224002). The range of absorbance values ( 0.145 to 0.185) observed for this subset of data is relatively small and should not result in a severe nonlinear response in absorbance with respect to changes in concentration, assuming that the detector was operating in a linear mode. B 10 2.6 Identification of Any Interfering Species The absorption spectra that were created using the synthetic background spectrum as I 0 were visually inspected for interfering or unidentified species. Only the tracer gas SF 6 and common atmospheric gases were identified in the absorption spectra. Water vapor was the only interfering species that exhibited spectral features in the wavenumber region used to analyze for SF 6.

2.7 Generation of Relevant Reference Spectra from the HITRAN Database Several reference spectra of selected atmospheric gases, including CH 4, N 2 O, CO,

CO 2, and H 2 O, were generated from the HITRAN database using Etrans ( Ontar Corporation, North Andover, MA). Spectra of the individual target gases were originally generated at a nominal 1 cm 1 resolution with triangular apodization at a temperature of 295K and atmospheric pressure of 760 Torr. Each spectrum was generated at a pathlength of 108 m. An absorption file compatible with Grams/ 32 ( Galactic, Salem,

NH) was selected as the output from Etrans. After the original set of reference spectra were generated and used in the CLS analysis, analyses conducted by SpectraSoft Technology revealed that the true resolution of the instrument was 1.462 cm 1. A new set of reference spectra was generated at 1.462 cm 1 resolution and the CLS analyses were repeated.

2.8 Inspection of the Absorbance Files for Wavenumber Shifts and Changes in Resolution Prior to analyzing the data with the CLS methods, the reference spectra were compared to the field absorption spectra for evidence of wavenumber shifts. If any wavenumber shifts were found, the reference spectra were adjusted by using the " peak B 11 align" subroutine in Grams/ 32. The data point density and spacing of the reference and field spectra were matched by using the " interpolate" routine in Grams/ 32.

The innovative nonlinear analysis method automatically determines the wavenumber shift in the single beam field spectra relative to the reference spectra generated from Etrans and calculates the actual spectral resolution of the field spectra. The field spectra exhibited a constant 0.5 cm 1 shift relative to the reference spectra generated from Etrans.

The actual spectral resolution was relatively constant, but, at a value of 1.462 ± 0.011 cm

1, was significantly higher than expected for an instrument operating at a nominal 1 cm 1 resolution. These data are plotted in Figure 9 and imply that, although the instrument was stable, it might not have been operating properly initially at the beginning of the field study.

2.9 Development and Evaluation of an Analysis Method The method used to determine the concentrations of target gases from OP/ FTIR spectra should account for the inherent nonlinearities in the response of the instrument.

There are two types of nonlinearity that can affect the accuracy of the concentration data reported by an OP/ FTIR monitor: detector nonlinearity and nonlinearity in absorbance.

Evidence of detector nonlinearity was discussed in Section 2.1.1 of this report and,

unfortunately, no analysis method can account for this type of nonlinearity. The OP/ FTIR system can also exhibit a nonlinearity in the change in absorbance with respect to changes in concentration. This nonlinearity is due to the convolution of the instrument line shape function, which is influenced by the resolution and apodization used to collect and process the interferograms, with the spectral data. The nonlinearity with respect to changes in absorbance can be accounted for by using a multilevel calibration model or some other type of nonlinear analysis algorithm. A multilevel CLS analysis and an innovative nonlinear algorithm have been previously applied successfully to APPCD field data collected at a concentrated swine production facility to account for the nonlinearity B 12 in the absorbance over the wide range of concentration pathlength products of the targets gases detected at that site.

The spectral data from the Augusta study were analyzed using four different methods.

Three methods were based on a CLS analysis using AutoQuant3 ( MIDAC, Irvine, CA),

while the fourth used an innovative nonlinear algorithm developed by Dr. Bill Phillips of SpectraSoft Technology ( Tullahoma, TN). 6 A matrix of the wavenumber ranges, target gases, and interfering species is given in Table 1. Different sets of reference spectra were used for the three CLS methods. One CLS method used a set of reference spectra from the Hanst 1.0 cm 1 spectral library ( Infrared Analysis, Inc., Anaheim, CA). Another CLS method used a set of reference spectra of atmospheric gases generated from the HITRAN database using Etrans and a reference spectrum of SF 6 from the NIST Standard Reference Database 79 ( Gaithersburg, MD). For this method, the spectra of the atmospheric gases were generated at a concentration pathlength product that produced absorbance values of the analytical IR bands near the median of those found in the field spectra. The third CLS method also used a set of reference spectra of the atmospheric gases generated from the HITRAN database using Etrans and a reference spectrum of SF 6 from the NIST database. A multilevel calibration was used for this method, with reference spectra of the atmospheric gases generated at concentration pathlength products corresponding to 10%

lower, 10% higher, the median, and midpoints between the median and the high and low absorbance values of those in the field spectra. The concentration pathlength products used for this multilevel CLS analysis are given in Table 2. B 13 Table 1. Analysis Region Matrix for CLS Analyses Analyte 900.20   980.70 cm 1 2083.9   2223.3 cm 1 2881.9   2929.2 cm 1 SF6 !

H2O( 1) !

CO !

N2O !

H2O( 2) !

CH4 !

H2O( 3) !

Table 2. Concentration Pathlength Products ( ppm m) for Multilevel CLS Analysis Analyte Low  10% Midpoint 1 Median Midpoint 2 High + 10%

SF6     1     H2O( 1) 1080000 1350000 1620000 1890000 2160000 CO 108 135 162 189 216 N2O 31.32 32.94 34.56 36.18 37.8 H2O( 2) 1080000 1350000 1620000 1890000 2160000 CH4 140.4 237.6 334.8 432 540 H2O( 3) 1080000 1350000 1620000 1890000 2160000 2.10 Comparison of the Concentration Values Generated by the Automated Multivariate Data Analysis Method to Manual Comparison Method or Advanced Nonlinear Algorithms Selected absorption files were analyzed by the manual comparison method described in Section <IP_ADDRESS>.1 of the FT IR Open Path Monitoring Guidance Document to check the output of the automated CLS method. An example of this procedure is given in Table 3 for SF6 for data files that represent the extremes in the reported concentration values. B 14 Table 3. Reported Concentration Values of Selected Files Using the Comparison and Multilevel CLS Methods File Number Comparison Method ( ppm) Multilevel CLS ( ppm)

d0224002 0.054 0.047 d0224089 0.036 0.028 d0224291 0.061 0.059 d0224305 0.006 0 As shown in Table 3, the reported values for SF6 from the multilevel CLS analysis are very similar to those determined by using the comparison method for these selected files. There is a slight positive bias in the concentration values determined by the comparison method because of interference from a water vapor band. Otherwise, the two methods are comparable for these representative data files.

More extensive comparisons were made between the single level CLS analyses using reference spectra from the Hanst spectral library and those generated from Etrans, the multilevel CLS analysis with reference spectra generated from Etrans, and an analysis using the innovative nonlinear algorithm. Dr. Phillips of SpectraSoft Technology performed the nonlinear analysis under a subcontractual agreement with ManTech under WA IV 119. The concentration values of SF6 and selected atmospheric gases determined by using the different analysis methods are given in Attachments 1   4. The mean concentration values reported from the four different analysis methods are summarized in Table 4. Also included in Table 4 are the results from the original CLS analyses using reference spectra generated from Etrans using a nominal 1

cm 1 resolution.

The mean concentrations of SF6 reported by each of the analysis methods were nearly identical even though the concentration pathlength products of the reference spectra for SF6 were significantly different in the single level CLS method using the Hanst reference spectrum ( 66 ppm m, Absmax = 1.5578) and the other methods, which used a reference spectrum from the NIST database ( 1 ppm m, Absmax = 0.02811).

The mean concentrations of CH4 during this monitoring period were similar for the B 15 Table 4. Mean Concentration Values ( ppm) for SF6 and Selected Atmospheric Gases Method SF6 CH4 CO N2O H2O ( 1) H2O ( 2) H2O ( 3) CO2 CLS Hanst, Single Level 0.04 3.006 2.348 0.378         CLS Etrans, Single Level ( 1 cm 1) 0.04 2.256 1.312 0.321 11820 12464 11539 C CLS Etrans, Single Level ( 1.462 cm 1) 0.04 2.68 2.058 0.35 15531 15841 12719 C CLS Etrans, Multilevel ( 1 cm 1) 0.04 2.243 1.267 0.321 11519 11317 11344 C CLS Etrans, Multilevel ( 1.462 cm 1) 0.04 2.671 2.161 0.348 15095 16492 12328   Nonlinear 0.04 2.758 2.208 0.382 9496     519.2 two CLS methods using reference spectra generated from Etrans at 1.462 cm 1 resolution, but were slightly higher for the nonlinear algorithm and the CLS method using the Hanst reference spectra. There were significant differences between the two CLS methods using Etrans reference spectra generated at either a nominal 1 cm 1 resolution or 1.462 cm 1 resolution. In each case, the CLS method using the nominal 1 cm 1 resolution Etrans reference spectra under reported the mean concentration.

The mean concentrations of CO and N2O reported by the nonlinear algorithm were slightly higher than those reported by the CLS methods using the 1.462 cm 1 Etrans reference spectra, whereas the water vapor concentration reported by the nonlinear algorithm was lower than that reported by the CLS methods. The reasons for these discrepancies are not known, but could include differences in developing the synthetic background spectrum for the CLS analyses and the fitted polynomial background for the nonlinear algorithm or the nonlinearity in the data caused by the saturated detector. The cause of these discrepancies has not been investigated further. The mean concentration for CO2 reported from the nonlinear algorithm was 519.2 ppm, which is slightly higher than normal ambient levels. The concentration of CO2 was not reported for the CLS methods because of the difficulties in analyzing for this gas in 1 cm 1 resolution spectra due to spectral overlap with CO and water vapor. B 16 2.11 Development of Relevant Control Charts As discussed above in Sections 2.2 and 2.3, control charts were developed for the signal strength and the random baseline noise, respectively. Control charts were also developed for the concentrations of selected atmospheric gases over time. These charts were developed from the concentration data reported by the multilevel CLS method and are given in Figures 10   14.

The reported concentrations of SF6 fluctuated between 28 and 50 ppb throughout most of the monitoring period and was relatively constant ( 38 ± 9 ppb) except for a sharp increase that was observed in files d0224290 and d0224291 ( see Figure 10). The concentration of SF6 decreased rapidly after file # d0224291 and was not detected in files after d0224300.

The reported concentration of CH4 was more variable, 2.671 ± 0.729 ppm ( see Figure 11). The pathaveraged concentration ranged from near or slightly below ambient background levels to more than 5.5 ppm. Although the concentration of SF6 was relatively constant throughout the monitoring period, the CH4 concentrations increased rapidly during three separate episodes. No other gases exhibited increases in concentrations during these time periods.

The path averaged concentration of carbon monoxide was relatively high ( 2.161 ± 0.181) for ambient measurements. High concentrations of CO were detected inside the spectrometer of the ETG system evaluated at RTP, NC. The CO concentration in this instrument increased over time. Purging the spectrometer box with dry N2 removed the CO from the system. This procedure should be done on all ETG systems in the field. The concentration of CO was relatively constant, but showed a steady increase near the end of the monitoring period ( see Figure 12).

The concentrations of N2O were relatively constant ( 0.348 ± 0.010 ppm) and slightly higher than expected ambient levels ( see Figure 13). Slight increases in the N2O concentrations were observed near the end of the monitoring period. Assuming that the ambient concentrations of N2O were constant, these results indicate that the instrument was stable throughout this monitoring period.

As a quality control check, the water vapor concentration was measured in three different regions.

Region 1 corresponds to the analysis region used for SF6 between 900.20 and 980.70 cm 1; region 2 corresponds to the analysis region used for CO and N2O between 2083.90 and 2223.3 cm 1; and region 3 B 17 corresponds to the analysis region used for CH4 between 2881.9 and 2929.2 cm 1. The concentrations of water vapor reported for each region were in close agreement and on average were approximately 14,500 ppm. This path averaged concentration is equivalent to approximately 11 Torr. If the water vapor concentration was measured by some independent means during the field study, these data could be used to assess the accuracy of the OP/ FTIR data.

3.0 Conclusions and Recommendations The QC procedures used to assess the instrument operation during the Augusta field study indicate that the instrument was stable throughout the monitoring period represented by the subset of data analyzed for this work assignment. However, these procedures revealed significant problems in the performance of the system and in the initial setup of the instrument. The single beam field spectra exhibited a wavenumber shift of 0.5 cm 1 relative to the reference spectra generated from Etrans. Also, the instrument resolution was calculated to be approximately 1.46 cm 1, instead of the selected value of 1.0 cm 1. In addition to these problems, all of the single beam spectra from this subset of data exhibit evidence of detector saturation. As a result, the instrument was most likely operating in a nonlinear mode during this study, which makes the accuracy of the reported concentration values highly questionable. Although different analysis methods and algorithms can be used to account for nonlinearities due to the convolution of the instrument response function on the spectral data, methods to correct for the nonlinearities due to detector saturation do not exist. The likelihood of detector saturation can be minimized by examining the single beam spectra during the initial instrument setup. Procedures for the initial instrument setup are given in EPA sponsored guidance documents1,2 and ASTM standards. 3,4 These documents should be reviewed and adhered to during future studies with the OP/ FTIR system. In addition to these documents, an example of a USEPA audit on an OP/ FTIR field study, including an extensive audit questionnaire, has been presented and is very helpful in applying many of the operating principles and quality control procedures discussed in these documents to OP/ FTIR field data. 7 The comparison of the data collected by the roof vent OP/ FTIR system to those obtained by manual bag sampling with subsequent analysis by FTIR spectrometry is of particular interest to the APPCD.

Because of the uncertainties in the OP/ FTIR data, conclusions drawn from this comparison should be made with the caveat that the OP/ FTIR instrument was most likely operating in a nonlinear mode due to detector saturation. B 18 4.0 Literature Cited 1. Russwurm, G. M. and Childers, J. W., FT IR Open Path Monitoring Guidance Document, 3rd Edition, TR 4423 99 03, ManTech Environmental Technology, Inc., Research Triangle Park, NC, June, 1999.

2. Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air, 2nd Edition, EPA/ 625/ R 96/ 010b, Center for Environmental Research Information, Office of Research & Development, U. S. Environmental Protection Agency, Cincinnati, OH 45268, January 1997.

3. E 1865 Standard Guide for Open Path Fourier Transform Infrared ( OP/ FT IR) Monitoring of Gases and Vapors in Air, Annual Book of ASTM Standards, Vol 03.06, American Society for Testing and Materials, West Conshohocken, PA.

4. E 1982 Standard Practice for Open Path Fourier Transform Infrared ( OP/ FT IR) Monitoring of Gases and Vapors in Air, Annual Book of ASTM Standards, Vol 03.06, American Society for Testing and Materials, West Conshohocken, PA.

5. Griffiths, P. R. and deHaseth, J. A., Fourier Transform Infrared Spectrometry, John Wiley & Sons, Inc.( 1986), pp. 56 65.

6. Phillips, B., Moyers, R., and Lay, L. T., " Improved FTIR Open Path Remote Sensing Data Reduction Technique," Proceedings of Optical Sensing for Environmental and Process Monitoring, VIP 37, Air & Waste Management Association, Pittsburgh, PA, 1995, pp. 374 388.

7. Childers, L. O., " The USEPA QA Auditor is Scheduled for a Visit. What Can I Expect?", Proceedings of Optical Remote Sensing for Environmental and Process Monitoring, VIP 55, Air & Waste Management Association, Pittsburgh, PA, 1996, pp. 127 138. B 19 5 0 0 1 0 0 0 1 5 0 0 2000 2 5 0 0 3 0 0 0 3 5 0 0 4 0 0 0 4 5 0 0 Single Beam Intensity Wavenumber ( cm )  1 Figure 1. Single beam OP/ FTIR spectrum collected during the Augusta study with a 108 m pathlength.

5 0 0 1 0 0 0 1 5 0 0 2 0 0 0 2 5 0 0 3 0 0 0 3 5 0 0 4 0 0 0 4 5 0 0 Single Beam Intensity Wavenumber ( cm )  1 Figure 2. Single beam OP/ FTIR spectrum collected at Research Triangle Park with a 414 m pathlength. B 20 6 7 .5 6 8 .5 6 9 .5 7 0 .5 Signal Intensity Signal S t rength at 9 8 5 cm  1 2 2 2 4 2 6 2 8 2 1 0 2 1 2 2 1 4 2 1 6 2 1 8 2 2 0 2 2 2 2 2 4 2 2 6 2 2 8 2 3 0 2 File N umber 6 7 .0 6 8 .0 6 9 .0 7 0 .0 Figure 3. Single beam signal intensity ( in arbitrary units) at 985 cm 1.

0 .8 3 5 0 .8 4 5 0 .8 5 5 Relative Signal Intensity Relative Signal Strength ( 2 5 0 0 / 9 8 5 )

2 2 2 4 2 6 2 8 2 1 0 2 1 2 2 1 4 2 1 6 2 1 8 2 2 0 2 2 2 2 2 4 2 2 6 2 2 8 2 3 0 2 File N umber 0 .8 5 0 0 .8 4 0 0 .8 3 0 Figure 4. Relative single beam signal intensity at 2500 cm 1 ratioed to that at 985 cm 1. B 21 0 .1 9 5 0 .2 0 5 0 .2 1 5 Relative Signal Intensity Relat ive S ignal Strength ( 4 4 0 0 / 9 8 5 )

2 2 2 4 2 6 2 8 2 1 0 2 1 2 2 1 4 2 1 6 2 1 8 2 2 0 2 2 2 2 2 4 2 2 6 2 2 8 2 3 0 2 File N umber 0 .2 1 0 0 .2 0 0 0 .1 9 0 Figure 5. Relative single beam signal intensity at 4400 cm 1 ratioed to that at 985 cm 1.

File N umber 0 .0 5 0 .1 0 0 .1 5 0 .2 0 0 .2 5 0 .3 0 0 .3 5 0 .4 0 0 .4 5 Thousandths RMS Deviation ( Abs Units) Random Baseline Noise 9 5 8  1 0 0 8 cm 1 3 2 3 4 3 63 8 3 1 03 12 3 1 43 1 6 3 1 83 2 0 3 2 23 24 3 2 6 3 2 83 30 3 Figure 6. Random baseline noise measured between 958 and 1008 cm 1. B 22 File Number 0 .0 3 0 .0 4 0 .0 5 0 .0 6 0 .0 7 0 .0 8 Thousandths 2 48 0  2 5 3 0 cm 1 3 2 3 4 3 6 3 8 3 1 0 3 1 2 3 1 4 3 1 6 3 1 8 3 2 0 3 2 2 3 2 4 3 2 6 3 2 8 3 3 03 RMS Deviation ( Abs Units) Random Baseline Noise Figure 7. Random baseline noise measured between 2480 and 2530 cm 1.

File N umber 0 .1 5 0 .2 0 0 .2 5 0 .3 0 0 .3 5 0 .4 0 Thousandths 4 3 7 5  4 42 5 cm 1 3 2 3 4 3 6 3 8 3 1 0 3 1 2 3 1 4 3 1 6 3 1 8 3 2 0 3 2 2 3 2 4 3 2 6 3 2 8 3 3 0 3 RMS Deviation ( Abs Units) Random Baseline Noise Figure 8. Random baseline noise measured between 4375 and 4425 cm 1. B 23 0.0 0.4 0.8 1.2 1.6 Wavenumbers 2 18 34 50 66 82 98 114 130 146 162 178 194 210 226 242 258 274 290 306 File Number resolution shift Figure 9. Measurement of the resolution and wavenumber shift calculated from the nonlinear algorithm.

0 0 .0 1 0 .0 2 0 .0 3 0 .0 4 0 .0 5 0 .0 6 0 .0 7 S F6 Concentration ( ppm)

File N um be r 2 2 2 4 2 6 2 8 2 1 0 2 1 2 2 1 4 2 1 6 2 1 8 2 2 0 2 2 2 2 2 4 2 2 6 2 2 8 2 3 0 2 Figure 10. Concentration of SF6 Determined from Multilevel CLS Analysis. B 24 1 2 3 4 5 6 M ethane Concentration ( ppm)

File N um ber 2 2 2 4 2 6 2 8 2 1 0 2 1 2 2 1 4 2 1 6 2 1 8 2 2 0 2 2 2 2 2 4 2 2 6 2 2 8 2 3 0 2 Figure 11. Concentration of CH4 Determined from Multilevel CLS Analysis.

1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 Concentration ( ppm) Carbon M onoxide File N umber 2 2 2 4 2 6 2 8 2 1 02 1 2 2 1 4 2 16 2 1 8 2 2 0 2 2 2 2 2 4 2 2 6 2 2 8 2 3 0 2 Figure 12. Concentration of CO Determined from Multilevel CLS Analysis. B 25 0 .3 3 0 .3 4 0 .3 5 0 .3 6 0 .3 7 0 .3 8 N it rous O xide File N um ber Concentration ( ppm)

2 2 2 4 2 6 2 8 2 1 0 2 1 2 2 1 4 2 1 6 2 1 8 2 2 0 2 2 2 2 2 4 2 2 6 2 2 8 2 3 0 2 Figure 13. Concentration of N2O Determined from Multilevel CLS Analysis.

8 1 0 1 2 1 4 1 6 1 8 2 0 2 2 Thousands Concentration ( ppm) W ater V apor File N um ber Region 1 Region 2 Region 3 2 2 2 4 2 6 2 8 2 1 0 2 1 2 2 1 4 2 1 6 2 1 8 2 2 0 2 2 2 2 2 4 2 2 6 2 2 8 2 3 0 2 Figure 14. Concentration of H2O Determined from Multilevel CLS Analysis. B 26 Attachment 1 Concentration Data from CLS Single Level Calibration Using Hanst 1.0 cm 1 Reference Spectra B 27 CLS Single Level Calibration Using Hanst 1.0 cm 1 Reference Spectra File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

2 2.645 2.487 0.384 0.051 14540 12863 12074 3 2.508 2.433 0.383 0.049 14707 12963 12233 4 2.416 2.372 0.381 0.046 14629 13017 12352 5 2.398 2.472 0.383 0.045 14828 13110 12424 6 2.459 2.403 0.382 0.043 14650 13083 12442 7 2.508 2.385 0.382 0.042 14743 13085 12402 8 2.595 2.435 0.383 0.043 14693 13089 12383 9 2.786 2.367 0.382 0.047 14852 13141 12437 10 2.864 2.360 0.381 0.043 14891 13137 12467 11 2.946 2.381 0.381 0.042 14824 13106 12425 12 2.849 2.388 0.380 0.041 14592 13126 12447 13 2.698 2.321 0.379 0.045 14880 13221 12605 14 2.643 2.378 0.379 0.046 14983 13237 12553 15 2.628 2.395 0.379 0.046 15038 13246 12528 16 2.599 2.325 0.377 0.044 14941 13235 12575 17 2.583 2.327 0.377 0.048 14953 13241 12618 18 2.584 2.312 0.376 0.045 14962 13286 12647 19 2.553 2.302 0.375 0.043 15002 13302 12728 20 2.631 2.293 0.374 0.045 15095 13348 12721 21 2.624 2.306 0.374 0.048 15132 13381 12736 22 2.503 2.297 0.373 0.044 15029 13346 12704 23 2.432 2.276 0.372 0.047 15126 13427 12785 24 2.495 2.269 0.371 0.046 15233 13460 12844 25 2.459 2.227 0.369 0.042 15256 13491 12922 26 2.309 2.200 0.369 0.044 15244 13463 12825 27 2.28 2.190 0.368 0.043 15036 13398 12757 28 2.269 2.172 0.368 0.043 14996 13385 12751 29 2.411 2.181 0.368 0.036 14836 13391 12755 30 2.361 2.189 0.368 0.045 15106 13393 12748 CLS Single Level Calibration Using Hanst 1.0 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 28 31 2.392 2.177 0.368 0.038 14792 13261 12541 32 2.468 2.165 0.367 0.041 14967 13358 12691 33 2.283 2.145 0.367 0.041 14875 13302 12599 34 2.316 2.143 0.367 0.043 14791 13199 12448 35 2.278 2.149 0.368 0.031 14483 13197 12419 36 2.136 2.143 0.369 0.033 14341 13114 12359 37 2.177 2.146 0.367 0.036 14550 13208 12485 38 2.205 2.154 0.368 0.033 14709 13304 12572 39 2.168 2.168 0.367 0.036 14780 13333 12606 40 2.219 2.185 0.368 0.036 14858 13323 12638 41 2.077 2.140 0.368 0.032 14482 13154 12401 42 2.145 2.139 0.368 0.035 14655 13216 12517 43 2.165 2.155 0.367 0.041 14833 13253 12509 44 2.363 2.143 0.367 0.039 14884 13340 12673 45 2.375 2.162 0.368 0.035 14873 13375 12706 46 2.786 2.170 0.366 0.042 15072 13414 12716 47 2.685 2.165 0.366 0.045 14859 13301 12568 48 2.54 2.156 0.366 0.042 14677 13220 12433 49 2.472 2.151 0.367 0.042 14557 13110 12304 50 2.499 2.152 0.366 0.040 14792 13210 12461 51 2.489 2.163 0.368 0.032 14581 13251 12495 52 2.352 2.154 0.367 0.036 14918 13418 12744 53 2.314 2.165 0.367 0.041 14980 13391 12734 54 2.236 2.178 0.367 0.041 14852 13300 12590 55 2.316 2.168 0.367 0.041 14879 13311 12611 56 2.286 2.153 0.367 0.038 14809 13308 12563 57 2.266 2.166 0.366 0.042 14936 13330 12561 58 2.285 2.151 0.366 0.037 14874 13317 12518 59 2.349 2.177 0.367 0.037 14867 13329 12521 CLS Single Level Calibration Using Hanst 1.0 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 29 60 2.579 2.171 0.366 0.040 14884 13332 12493 61 2.303 2.174 0.366 0.041 14899 13400 12547 62 2.243 2.158 0.366 0.040 14999 13435 12685 63 2.539 2.166 0.366 0.033 14834 13384 12649 64 2.584 2.194 0.366 0.037 14907 13366 12625 65 2.465 2.153 0.365 0.040 14802 13288 12506 66 2.612 2.159 0.365 0.042 14778 13281 12460 67 2.718 2.167 0.365 0.038 14575 13211 12382 68 2.549 2.196 0.366 0.038 14423 13109 12197 69 2.523 2.169 0.365 0.042 14547 13108 12248 70 2.54 2.158 0.366 0.043 14473 13119 12224 71 2.742 2.167 0.366 0.043 14604 13177 12335 72 2.714 2.170 0.366 0.037 14621 13156 12335 73 2.573 2.159 0.366 0.039 14524 13140 12273 74 2.585 2.151 0.366 0.038 14702 13251 12489 75 2.671 2.156 0.366 0.041 14663 13152 12323 76 2.638 2.158 0.366 0.039 14757 13272 12494 77 2.73 2.185 0.366 0.037 14885 13405 12654 78 2.809 2.155 0.365 0.038 14680 13306 12549 79 2.667 2.168 0.366 0.041 14522 13165 12304 80 2.592 2.225 0.367 0.040 14678 13248 12432 81 2.528 2.171 0.366 0.041 14489 13137 12261 82 2.522 2.182 0.366 0.041 14474 13101 12242 83 2.482 2.170 0.366 0.038 14587 13143 12265 84 2.649 2.163 0.366 0.038 14828 13338 12580 85 2.688 2.160 0.366 0.038 14752 13269 12470 86 2.431 2.168 0.366 0.041 14583 13173 12255 87 2.555 2.163 0.366 0.034 14509 13180 12293 88 2.355 2.162 0.366 0.032 14540 13214 12319 CLS Single Level Calibration Using Hanst 1.0 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 30 89 2.288 2.163 0.366 0.031 14412 13248 12405 90 2.47 2.171 0.366 0.039 14564 13150 12248 91 2.747 2.180 0.366 0.038 14478 13158 12250 92 2.841 2.159 0.366 0.040 14595 13191 12332 93 2.942 2.166 0.366 0.039 14597 13205 12382 94 3.287 2.163 0.366 0.041 14808 13294 12485 95 3.509 2.163 0.366 0.041 14632 13240 12415 96 3.718 2.163 0.365 0.041 14798 13300 12502 97 3.341 2.163 0.365 0.043 14694 13250 12428 98 2.877 2.171 0.366 0.043 14666 13214 12376 99 2.975 2.169 0.367 0.040 14748 13259 12432 100 3.126 2.169 0.367 0.040 14717 13263 12456 101 3.025 2.164 0.366 0.042 14718 13226 12392 102 2.947 2.164 0.366 0.042 14712 13225 12431 103 3.014 2.170 0.366 0.043 14633 13190 12352 104 3.091 2.171 0.367 0.040 14589 13208 12394 105 3.219 2.172 0.366 0.041 14678 13207 12394 106 3.633 2.173 0.367 0.041 14627 13265 12460 107 4.46 2.173 0.367 0.040 14838 13360 12611 108 4.815 2.174 0.366 0.039 14946 13438 12638 109 4.549 2.181 0.367 0.039 14971 13409 12633 110 4.244 2.175 0.367 0.039 14913 13408 12644 111 4.139 2.172 0.367 0.042 14915 13403 12644 112 4.052 2.171 0.366 0.043 14945 13396 12649 113 4.162 2.172 0.367 0.041 14989 13441 12701 114 4.182 2.176 0.367 0.038 15018 13451 12725 115 4.255 2.183 0.367 0.043 15172 13483 12741 116 4.299 2.180 0.368 0.040 15044 13512 12787 117 4.581 2.184 0.368 0.041 15187 13598 12829 CLS Single Level Calibration Using Hanst 1.0 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 31 118 4.948 2.183 0.368 0.040 15355 13631 12850 119 5.45 2.185 0.368 0.039 15378 13639 12891 120 5.51 2.181 0.368 0.040 15399 13653 12933 121 4.957 2.186 0.368 0.041 15438 13627 12898 122 4.567 2.199 0.368 0.037 15388 13629 12871 123 4.38 2.216 0.369 0.038 15330 13630 12864 124 4.73 2.225 0.369 0.039 15448 13656 12815 125 5.264 2.222 0.369 0.039 15518 13731 12876 126 5.967 2.210 0.369 0.039 15536 13806 12978 127 6.026 2.213 0.370 0.039 15711 13810 13062 128 6.001 2.213 0.370 0.039 15623 13803 13053 129 5.908 2.203 0.370 0.038 15591 13798 13070 130 5.454 2.202 0.370 0.038 15623 13797 13102 131 5.518 2.215 0.370 0.037 15664 13839 13146 132 5.468 2.210 0.370 0.037 15570 13832 13143 133 5.173 2.210 0.370 0.038 15636 13783 13089 134 4.964 2.212 0.370 0.039 15469 13756 13086 135 5.376 2.203 0.370 0.037 15494 13728 13073 136 6.26 2.200 0.370 0.038 15467 13735 13092 137 4.888 2.197 0.370 0.039 15112 13548 12897 138 4.01 2.210 0.370 0.037 15094 13491 12814 139 3.55 2.218 0.370 0.040 15199 13505 12850 140 3.089 2.225 0.372 0.042 14985 13373 12712 141 2.736 2.238 0.373 0.045 14941 13341 12628 142 2.891 2.229 0.373 0.043 14823 13288 12624 143 2.902 2.220 0.373 0.039 14768 13220 12505 144 2.857 2.218 0.373 0.043 14759 13209 12489 145 2.988 2.222 0.373 0.046 14803 13164 12405 146 3.04 2.232 0.374 0.046 14698 13100 12347 CLS Single Level Calibration Using Hanst 1.0 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 32 147 3.044 2.246 0.375 0.046 14712 13080 12292 148 2.941 2.232 0.375 0.043 14632 13093 12348 149 2.887 2.234 0.375 0.042 14576 13056 12301 150 3.118 2.233 0.376 0.042 14403 12969 12145 151 3.131 2.231 0.376 0.043 14470 12935 12144 152 3.068 2.227 0.377 0.046 14368 12890 12043 153 2.93 2.229 0.376 0.046 14326 12810 11941 154 3.004 2.254 0.377 0.044 14175 12740 11858 155 3.007 2.241 0.377 0.044 14167 12717 11847 156 2.989 2.236 0.377 0.045 14161 12698 11823 157 2.761 2.245 0.377 0.044 14273 12722 11861 158 2.66 2.247 0.376 0.043 14024 12675 11790 159 2.556 2.251 0.377 0.042 13915 12636 11735 160 2.663 2.263 0.377 0.040 13892 12613 11699 161 2.805 2.280 0.378 0.043 13894 12579 11652 162 2.788 2.290 0.378 0.045 14039 12604 11614 163 2.809 2.346 0.379 0.044 13873 12490 11488 164 2.832 2.383 0.380 0.043 13821 12491 11474 165 2.791 2.298 0.379 0.043 13736 12527 11570 166 2.745 2.278 0.379 0.044 13607 12532 11596 167 2.724 2.278 0.379 0.047 13924 12552 11637 168 2.61 2.261 0.378 0.047 13932 12532 11608 169 2.574 2.278 0.378 0.047 13874 12512 11598 170 2.459 2.299 0.379 0.045 13806 12520 11609 171 2.316 2.357 0.379 0.044 13893 12513 11582 172 2.324 2.284 0.379 0.046 13811 12457 11521 173 2.505 2.295 0.379 0.047 13674 12343 11344 174 2.538 2.276 0.379 0.044 13558 12285 11296 175 2.342 2.277 0.379 0.045 13693 12386 11405 CLS Single Level Calibration Using Hanst 1.0 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 33 176 2.293 2.289 0.379 0.044 13659 12390 11391 177 2.328 2.297 0.378 0.047 13737 12376 11378 178 2.41 2.292 0.378 0.044 13681 12354 11355 179 2.432 2.286 0.379 0.044 13617 12322 11305 180 2.282 2.373 0.380 0.044 13615 12278 11189 181 2.187 2.293 0.379 0.047 13716 12305 11276 182 2.186 2.280 0.379 0.048 13650 12324 11348 183 2.199 2.279 0.378 0.044 13626 12318 11338 184 2.305 2.326 0.379 0.046 13490 12208 11153 185 2.3 2.317 0.380 0.048 13458 12176 11123 186 2.201 2.290 0.379 0.047 13560 12215 11187 187 2.175 2.283 0.379 0.044 13490 12283 11276 188 2.128 2.285 0.378 0.044 13749 12401 11444 189 2.154 2.284 0.378 0.041 13658 12398 11451 190 2.209 2.285 0.377 0.043 13812 12471 11517 191 2.342 2.286 0.378 0.042 13895 12472 11558 192 2.515 2.291 0.378 0.046 14011 12527 11648 193 2.582 2.298 0.377 0.044 14020 12600 11716 194 2.584 2.318 0.377 0.048 14084 12589 11696 195 2.735 2.339 0.378 0.047 14051 12589 11634 196 3.327 2.330 0.377 0.046 14018 12612 11717 197 4.492 2.309 0.377 0.047 14138 12632 11717 198 4.729 2.312 0.378 0.044 13895 12514 11557 199 4.625 2.324 0.379 0.043 13667 12324 11239 200 3.832 2.316 0.380 0.044 13472 12209 11126 201 3.182 2.305 0.381 0.046 13257 12022 10927 202 3.007 2.299 0.381 0.045 13133 11966 10868 203 3.279 2.297 0.382 0.043 13194 12066 11018 204 3.066 2.286 0.382 0.042 13202 12088 11059 CLS Single Level Calibration Using Hanst 1.0 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 34 205 2.815 2.293 0.382 0.044 13207 11986 10939 206 2.685 2.298 0.381 0.044 13075 11943 10855 207 2.557 2.304 0.382 0.047 13104 11885 10802 208 2.525 2.307 0.382 0.045 12655 11678 10425 209 2.559 2.313 0.383 0.044 12526 11526 10281 210 2.527 2.317 0.383 0.044 12350 11424 10086 211 2.491 2.322 0.383 0.042 12352 11439 10153 212 2.398 2.310 0.383 0.044 12528 11490 10223 213 2.387 2.309 0.383 0.045 12592 11518 10255 214 2.379 2.312 0.382 0.045 12564 11514 10259 215 2.351 2.344 0.383 0.046 12496 11444 10134 216 2.399 2.319 0.383 0.044 12432 11418 10133 217 2.431 2.320 0.383 0.044 12501 11467 10194 218 2.461 2.319 0.383 0.045 12390 11378 10074 219 2.428 2.320 0.383 0.046 12304 11293 9948 220 2.384 2.358 0.384 0.045 12272 11247 9878 221 2.471 2.410 0.385 0.042 11974 11144 9706 222 2.516 2.372 0.384 0.045 12029 11180 9743 223 2.652 2.371 0.384 0.043 11996 11125 9675 224 2.899 2.412 0.384 0.041 12107 11253 9818 225 2.955 2.396 0.383 0.044 12475 11484 10090 226 3.215 2.431 0.384 0.049 12380 11280 9786 227 3.075 2.427 0.384 0.046 12190 11226 9680 228 2.827 2.412 0.384 0.046 12325 11315 9865 229 3.05 2.406 0.384 0.047 12515 11392 9995 230 2.823 2.389 0.384 0.046 12404 11331 9930 231 2.844 2.365 0.384 0.041 12179 11307 9971 232 3.223 2.381 0.384 0.043 12342 11356 9984 233 3.665 2.386 0.384 0.048 12447 11354 9960 CLS Single Level Calibration Using Hanst 1.0 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 35 234 4.641 2.401 0.383 0.045 12732 11577 10251 235 5.518 2.406 0.383 0.045 12850 11675 10364 236 4.718 2.435 0.384 0.046 12375 11294 9780 237 3.958 2.440 0.384 0.045 12400 11348 9784 238 3.846 2.430 0.384 0.046 12412 11401 9823 239 3.627 2.435 0.384 0.046 12554 11409 9877 240 3.536 2.406 0.384 0.047 12425 11355 9796 241 3.573 2.393 0.384 0.047 12432 11382 9762 242 3.316 2.391 0.385 0.046 12247 11209 9666 243 3.153 2.397 0.385 0.042 11903 11049 9535 244 3.121 2.413 0.386 0.044 11726 10863 9264 245 3.147 2.410 0.386 0.044 11829 10930 9336 246 3.075 2.389 0.386 0.045 11795 10890 9345 247 3.104 2.413 0.386 0.046 11840 10935 9389 248 2.969 2.477 0.386 0.045 11770 10879 9306 249 2.834 2.420 0.387 0.045 11682 10780 9232 250 2.75 2.404 0.386 0.046 11503 10704 9127 251 2.717 2.391 0.386 0.047 11593 10685 9113 252 2.876 2.400 0.386 0.044 11612 10739 9194 253 2.979 2.411 0.386 0.044 11666 10788 9256 254 2.612 2.404 0.387 0.044 11631 10807 9275 255 2.357 2.391 0.387 0.048 11806 10850 9366 256 2.434 2.457 0.388 0.046 11671 10790 9253 257 2.482 2.483 0.388 0.046 11484 10670 9055 258 2.539 2.484 0.389 0.045 11448 10602 8956 259 2.557 2.489 0.389 0.042 11269 10541 8853 260 2.598 2.462 0.388 0.045 11205 10417 8691 261 2.599 2.485 0.388 0.044 11188 10496 8785 262 2.59 2.456 0.387 0.047 11527 10632 9024 CLS Single Level Calibration Using Hanst 1.0 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 36 263 2.71 2.475 0.388 0.047 11604 10709 9084 264 2.735 2.451 0.387 0.045 11539 10720 9095 265 2.636 2.438 0.387 0.048 11592 10661 9060 266 2.699 2.441 0.387 0.044 11374 10607 8992 267 2.683 2.445 0.389 0.044 11291 10470 8786 268 2.655 2.531 0.389 0.045 11192 10421 8680 269 2.617 2.525 0.390 0.045 11129 10365 8607 270 2.592 2.508 0.389 0.045 11231 10400 8680 271 2.583 2.545 0.390 0.044 11141 10435 8705 272 2.541 2.588 0.390 0.044 11211 10494 8773 273 2.729 3.032 0.396 0.044 11395 10653 8830 274 3.351 2.849 0.394 0.045 11577 10765 9037 275 3.231 2.643 0.392 0.047 11571 10651 8969 276 3.168 2.582 0.391 0.046 11445 10630 8979 277 3.114 2.601 0.391 0.044 11408 10614 8901 278 3.024 2.770 0.393 0.045 11362 10599 8839 279 2.927 2.833 0.394 0.045 11410 10623 8877 280 2.85 2.837 0.394 0.043 11428 10650 8932 281 2.872 2.904 0.395 0.043 11409 10658 8908 282 2.883 2.862 0.394 0.041 11367 10623 8876 283 2.857 2.816 0.393 0.040 11106 10517 8738 284 2.864 2.774 0.393 0.044 11144 10433 8652 285 2.878 3.144 0.399 0.044 11090 10435 8519 286 2.898 3.075 0.398 0.041 11077 10486 8528 287 2.92 3.164 0.399 0.042 11019 10436 8376 288 2.964 3.187 0.399 0.044 11310 10587 8588 289 3.112 3.141 0.398 0.045 11373 10613 8591 290 3.124 3.118 0.398 0.056 10979 10673 8700 291 3.16 3.184 0.399 0.061 10781 10558 8383 CLS Single Level Calibration Using Hanst 1.0 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 37 292 3.237 3.267 0.400 0.015 10150 10554 8161 293 3.374 3.360 0.402 0.007 9832 10569 8054 294 3.452 3.217 0.399 0.005 9899 10674 8539 295 3.219 2.995 0.396 0.003 10027 10829 8963 296 3.166 3.028 0.396 0.002 10100 10906 9104 297 3.187 2.944 0.395 0.002 10081 10915 9122 298 3.152 2.879 0.394 0.001 10165 10942 9260 299 3.149 2.833 0.393 0.002 10243 11003 9371 300 3.328 2.957 0.395 0.001 10461 11176 9613 301 3.316 2.953 0.395 0.000 10561 11297 9747 302 3.224 2.860 0.394 0.000 10734 11401 9940 303 3.224 2.808 0.398 0.001 10926 11521 10114 304 3.369 2.827 0.403 0.000 11024 11581 10235 305 3.469 2.832 0.404 0.000 11013 11622 10241 306 3.562 2.848 0.407 0.000 11108 11660 10281 Avg 3.006 2.348 0.378 0.041 13614 12394 11329 Std 0.835 0.241 0.010 0.009 1524 1076 1470 B 38 Attachment 2 Concentration Data from CLS Single Level Calibration Using Etrans Reference Spectra B 39 CLS Single Level Calibration Using Etrans 1.462 cm 1 Reference Spectra File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

2 2.385 2.177 0.356 0.049 16341 16428 13537 3 2.271 2.134 0.354 0.048 16598 16565 13726 4 2.196 2.086 0.353 0.045 16610 16639 13848 5 2.182 2.167 0.354 0.044 16944 16763 13961 6 2.234 2.111 0.353 0.042 16808 16727 13973 7 2.275 2.097 0.353 0.041 16997 16729 13954 8 2.344 2.137 0.353 0.042 16889 16740 13917 9 2.508 2.084 0.353 0.046 16892 16801 13992 10 2.571 2.079 0.352 0.042 17113 16781 13971 11 2.637 2.095 0.352 0.041 17063 16748 13926 12 2.555 2.102 0.352 0.040 16839 16770 13959 13 2.431 2.049 0.350 0.044 16961 16892 14132 14 2.388 2.094 0.350 0.045 17081 16918 14111 15 2.376 2.108 0.349 0.044 17178 16933 14106 16 2.353 2.051 0.348 0.043 17110 16930 14161 17 2.340 2.053 0.348 0.046 16956 16940 14202 18 2.340 2.041 0.347 0.044 17114 16999 14248 19 2.316 2.034 0.346 0.042 17247 17016 14324 20 2.379 2.027 0.345 0.044 17224 17083 14315 21 2.374 2.038 0.345 0.047 17172 17119 14338 22 2.269 2.031 0.344 0.043 17200 17070 14290 23 2.211 2.016 0.343 0.046 17176 17166 14366 24 2.267 2.011 0.342 0.045 17344 17207 14435 25 2.235 1.978 0.341 0.041 17599 17254 14511 26 2.108 1.956 0.341 0.043 17502 17211 14389 27 2.080 1.948 0.339 0.041 17329 17123 14313 28 2.072 1.933 0.339 0.042 17238 17107 14317 29 2.195 1.940 0.340 0.035 17405 17123 14340 30 2.151 1.945 0.339 0.044 17260 17135 14352 CLS Single Level Calibration Using Etrans 1.462 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 40 31 2.177 1.934 0.340 0.037 17210 16964 14125 32 2.241 1.925 0.339 0.040 17259 17099 14302 33 2.085 1.908 0.338 0.040 17164 17020 14175 34 2.113 1.905 0.338 0.042 16933 16892 14017 35 2.080 1.910 0.340 0.030 17159 16892 13984 36 1.956 1.905 0.341 0.032 16881 16768 13880 37 1.995 1.908 0.339 0.035 16942 16890 14043 38 2.022 1.915 0.339 0.033 17310 17021 14173 39 1.992 1.928 0.339 0.035 17296 17055 14210 40 2.032 1.941 0.339 0.035 17402 17044 14225 41 1.910 1.902 0.340 0.031 17089 16832 13952 42 1.969 1.901 0.340 0.034 17131 16921 14114 43 1.990 1.914 0.338 0.040 17084 16982 14134 44 2.157 1.906 0.338 0.038 17218 17090 14303 45 2.168 1.922 0.339 0.034 17444 17138 14359 46 2.512 1.929 0.337 0.041 17304 17182 14364 47 2.426 1.923 0.337 0.044 16873 17041 14191 48 2.301 1.915 0.337 0.041 16795 16928 14026 49 2.242 1.909 0.339 0.041 16615 16782 13855 50 2.265 1.911 0.337 0.039 17049 16912 14019 51 2.258 1.921 0.339 0.031 17153 16965 14088 52 2.147 1.917 0.338 0.035 17452 17175 14375 53 2.113 1.925 0.338 0.039 17263 17142 14370 54 2.046 1.934 0.338 0.040 17073 17027 14189 55 2.116 1.925 0.338 0.040 17092 17055 14237 56 2.094 1.911 0.337 0.037 17150 17070 14241 57 2.079 1.923 0.337 0.041 17043 17091 14290 58 2.097 1.910 0.337 0.036 17272 17081 14244 59 2.149 1.931 0.337 0.036 17265 17093 14226 CLS Single Level Calibration Using Etrans 1.462 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 41 60 2.346 1.926 0.337 0.039 17094 17102 14259 61 2.115 1.930 0.337 0.040 17081 17183 14371 62 2.060 1.918 0.337 0.039 17298 17218 14431 63 2.304 1.925 0.337 0.032 17430 17149 14310 64 2.339 1.946 0.337 0.036 17320 17126 14266 65 2.239 1.912 0.336 0.039 17013 17025 14119 66 2.362 1.918 0.336 0.041 16886 17011 14062 67 2.450 1.922 0.336 0.037 16842 16928 13995 68 2.308 1.944 0.337 0.037 16610 16799 13793 69 2.287 1.921 0.336 0.041 16548 16807 13847 70 2.302 1.913 0.337 0.042 16430 16821 13838 71 2.471 1.921 0.336 0.042 16623 16893 13939 72 2.448 1.923 0.337 0.036 16984 16865 13940 73 2.329 1.915 0.337 0.038 16728 16844 13890 74 2.339 1.910 0.337 0.037 17036 16981 14109 75 2.411 1.913 0.337 0.040 16793 16854 13916 76 2.383 1.916 0.336 0.038 16982 17005 14111 77 2.463 1.941 0.336 0.036 17273 17168 14305 78 2.528 1.914 0.336 0.037 16933 17049 14177 79 2.407 1.922 0.337 0.040 16521 16864 13901 80 2.346 1.969 0.337 0.039 16800 16975 14039 81 2.287 1.925 0.337 0.040 16550 16821 13837 82 2.284 1.932 0.337 0.040 16475 16790 13834 83 2.253 1.923 0.337 0.037 16822 16852 13881 84 2.396 1.920 0.336 0.037 17110 17103 14239 85 2.428 1.917 0.337 0.037 17043 17015 14119 86 2.210 1.921 0.336 0.040 16636 16899 13883 87 2.317 1.917 0.336 0.033 16934 16909 13927 88 2.150 1.918 0.337 0.031 17094 16943 13970 CLS Single Level Calibration Using Etrans 1.462 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 42 89 2.092 1.921 0.337 0.030 16954 16969 14033 90 2.242 1.925 0.337 0.038 16735 16843 13835 91 2.474 1.932 0.337 0.037 16695 16853 13834 92 2.550 1.917 0.337 0.039 16722 16888 13912 93 2.635 1.923 0.337 0.038 16799 16911 13974 94 2.925 1.921 0.337 0.040 16954 17018 14078 95 3.113 1.920 0.337 0.040 16761 16959 14018 96 3.286 1.921 0.336 0.040 16960 17030 14100 97 2.972 1.920 0.336 0.042 16703 16971 14049 98 2.583 1.926 0.336 0.042 16640 16932 13994 99 2.667 1.924 0.337 0.039 16905 16994 14061 100 2.792 1.924 0.337 0.039 16859 17000 14091 101 2.708 1.920 0.337 0.041 16756 16952 14019 102 2.640 1.921 0.338 0.041 16769 16937 14036 103 2.694 1.926 0.338 0.042 16607 16887 13929 104 2.757 1.927 0.338 0.039 16691 16907 13968 105 2.868 1.927 0.338 0.040 16753 16908 13977 106 3.214 1.929 0.338 0.040 16666 16986 14053 107 3.908 1.930 0.337 0.039 17039 17107 14211 108 4.209 1.932 0.337 0.038 17197 17207 14248 109 3.987 1.937 0.337 0.038 17273 17183 14279 110 3.732 1.933 0.338 0.038 17200 17175 14297 111 3.645 1.930 0.337 0.041 17044 17170 14289 112 3.569 1.929 0.337 0.042 17060 17164 14293 113 3.663 1.930 0.337 0.040 17175 17218 14347 114 3.678 1.934 0.337 0.037 17363 17225 14369 115 3.737 1.941 0.338 0.042 17343 17259 14364 116 3.777 1.939 0.338 0.039 17363 17295 14436 117 4.019 1.943 0.338 0.040 17492 17410 14516 CLS Single Level Calibration Using Etrans 1.462 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 43 118 4.330 1.943 0.339 0.039 17734 17453 14541 119 4.745 1.945 0.339 0.038 17814 17456 14566 120 4.792 1.942 0.339 0.039 17804 17472 14598 121 4.332 1.946 0.339 0.040 17822 17442 14577 122 4.010 1.955 0.339 0.036 17960 17461 14582 123 3.858 1.969 0.339 0.037 17859 17460 14606 124 4.154 1.976 0.339 0.038 17951 17488 14584 125 4.603 1.976 0.340 0.038 18002 17579 14654 126 5.192 1.968 0.339 0.038 18089 17673 14762 127 5.240 1.970 0.340 0.038 18251 17686 14816 128 5.214 1.970 0.340 0.038 18207 17672 14792 129 5.133 1.962 0.340 0.037 18191 17656 14798 130 4.753 1.961 0.340 0.037 18230 17663 14829 131 4.806 1.972 0.341 0.036 18291 17707 14868 132 4.763 1.970 0.341 0.036 18188 17686 14849 133 4.514 1.968 0.341 0.037 18291 17630 14794 134 4.340 1.969 0.34 0.038 18035 17600 14786 135 4.685 1.961 0.340 0.036 18171 17576 14783 136 5.425 1.958 0.340 0.037 18054 17586 14788 137 4.275 1.953 0.341 0.038 17481 17347 14568 138 3.534 1.962 0.34 0.036 17628 17270 14463 139 3.149 1.969 0.341 0.039 17549 17288 14516 140 2.763 1.972 0.343 0.041 17158 17121 14377 141 2.468 1.982 0.344 0.044 16961 17075 14288 142 2.591 1.975 0.344 0.042 16931 16992 14224 143 2.600 1.967 0.344 0.038 17049 16907 14097 144 2.563 1.966 0.344 0.042 16835 16892 14079 145 2.675 1.968 0.345 0.045 16717 16836 13991 146 2.716 1.975 0.346 0.044 16643 16752 13913 CLS Single Level Calibration Using Etrans 1.462 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 44 147 2.718 1.987 0.347 0.045 16637 16714 13851 148 2.634 1.975 0.347 0.042 16643 16747 13929 149 2.589 1.976 0.347 0.041 16610 16695 13868 150 2.785 1.973 0.348 0.041 16466 16595 13718 151 2.790 1.972 0.349 0.042 16455 16535 13694 152 2.740 1.967 0.349 0.044 16205 16481 13590 153 2.620 1.967 0.349 0.045 16149 16379 13445 154 2.683 1.987 0.350 0.042 16066 16285 13372 155 2.684 1.977 0.350 0.043 16011 16250 13328 156 2.665 1.973 0.350 0.044 16017 16214 13274 157 2.474 1.981 0.349 0.043 16241 16247 13316 158 2.388 1.982 0.349 0.042 15919 16184 13233 159 2.301 1.985 0.349 0.041 15851 16132 13178 160 2.392 1.993 0.350 0.039 15913 16109 13140 161 2.511 2.007 0.351 0.042 15759 16063 13075 162 2.500 2.014 0.351 0.044 15839 16107 13083 163 2.517 2.056 0.351 0.043 15631 15965 12922 164 2.534 2.087 0.352 0.042 15626 15958 12889 165 2.501 2.020 0.351 0.042 15523 15995 12999 166 2.461 2.004 0.351 0.043 15286 16009 13029 167 2.445 2.005 0.352 0.045 15643 16027 13060 168 2.345 1.992 0.352 0.046 15615 15989 13014 169 2.317 2.004 0.351 0.046 15520 15974 13009 170 2.218 2.022 0.352 0.044 15624 15972 12994 171 2.100 2.068 0.352 0.043 15782 15968 12987 172 2.104 2.009 0.352 0.045 15577 15896 12917 173 2.256 2.015 0.352 0.046 15336 15754 12718 174 2.281 2.000 0.353 0.043 15286 15668 12630 175 2.122 2.001 0.352 0.044 15459 15820 12803 CLS Single Level Calibration Using Etrans 1.462 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 45 176 2.081 2.010 0.352 0.043 15490 15823 12788 177 2.109 2.017 0.351 0.046 15371 15806 12772 178 2.181 2.012 0.351 0.043 15443 15787 12745 179 2.195 2.007 0.352 0.043 15368 15739 12672 180 2.071 2.075 0.353 0.043 15317 15681 12568 181 1.990 2.013 0.352 0.046 15357 15705 12626 182 1.988 2.003 0.352 0.047 15243 15728 12701 183 1.998 2.003 0.351 0.043 15394 15722 12679 184 2.084 2.038 0.352 0.044 15198 15575 12455 185 2.082 2.031 0.353 0.046 15022 15534 12431 186 1.997 2.010 0.353 0.046 15163 15587 12494 187 1.977 2.006 0.352 0.043 15142 15668 12601 188 1.939 2.008 0.351 0.043 15531 15828 12809 189 1.962 2.007 0.351 0.040 15626 15829 12810 190 2.010 2.009 0.350 0.042 15637 15931 12903 191 2.121 2.009 0.35 0.041 15775 15937 12952 192 2.267 2.014 0.350 0.045 15827 16000 13041 193 2.324 2.021 0.349 0.043 15872 16092 13122 194 2.326 2.037 0.35 0.047 15835 16075 13104 195 2.450 2.056 0.350 0.045 15859 16059 13008 196 2.945 2.048 0.350 0.045 15816 16093 13089 197 3.918 2.032 0.349 0.046 15927 16121 13066 198 4.114 2.032 0.351 0.043 15755 15966 12889 199 4.029 2.038 0.352 0.042 15490 15726 12556 200 3.362 2.030 0.353 0.043 15191 15576 12430 201 2.819 2.018 0.354 0.045 14801 15347 12225 202 2.671 2.013 0.355 0.043 14707 15274 12138 203 2.899 2.013 0.355 0.042 14863 15398 12292 204 2.724 2.004 0.356 0.041 14966 15431 12361 CLS Single Level Calibration Using Etrans 1.462 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 46 205 2.510 2.008 0.356 0.043 14858 15299 12197 206 2.399 2.013 0.355 0.043 14675 15229 12093 207 2.292 2.015 0.356 0.046 14588 15161 12041 208 2.262 2.016 0.357 0.044 14143 14887 11627 209 2.288 2.018 0.358 0.043 13953 14689 11424 210 2.261 2.020 0.358 0.043 13740 14559 11217 211 2.228 2.025 0.358 0.041 13845 14578 11275 212 2.153 2.016 0.358 0.043 13952 14641 11340 213 2.143 2.015 0.358 0.044 13984 14684 11382 214 2.140 2.016 0.357 0.044 13990 14685 11408 215 2.115 2.041 0.358 0.045 13845 14596 11293 216 2.156 2.021 0.358 0.043 13817 14561 11272 217 2.180 2.022 0.358 0.043 13944 14627 11344 218 2.208 2.020 0.358 0.043 13799 14511 11212 219 2.179 2.019 0.358 0.045 13590 14405 11072 220 2.142 2.049 0.359 0.044 13621 14351 10978 221 2.210 2.091 0.360 0.041 13363 14195 10758 222 2.249 2.060 0.36 0.044 13261 14247 10833 223 2.364 2.058 0.359 0.042 13326 14176 10752 224 2.574 2.093 0.359 0.040 13585 14346 10931 225 2.622 2.085 0.358 0.043 13935 14627 11239 226 2.841 2.108 0.359 0.048 13573 14377 10908 227 2.726 2.103 0.359 0.045 13449 14317 10814 228 2.517 2.094 0.358 0.045 13653 14431 11002 229 2.704 2.090 0.358 0.045 13850 14528 11155 230 2.514 2.074 0.358 0.045 13718 14458 11076 231 2.527 2.055 0.359 0.040 13691 14421 11078 232 2.848 2.069 0.359 0.042 13807 14485 11127 233 3.215 2.074 0.359 0.047 13650 14470 11058 CLS Single Level Calibration Using Etrans 1.462 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 47 234 4.032 2.089 0.357 0.043 14259 14765 11383 235 4.765 2.095 0.357 0.044 14373 14886 11515 236 4.097 2.113 0.359 0.045 13688 14391 10871 237 3.468 2.116 0.359 0.044 13783 14470 10930 238 3.374 2.110 0.358 0.045 13769 14532 10989 239 3.192 2.114 0.358 0.045 13925 14546 11046 240 3.120 2.089 0.359 0.046 13720 14485 10976 241 3.152 2.079 0.359 0.046 13728 14513 10960 242 2.931 2.075 0.360 0.045 13552 14297 10813 243 2.788 2.077 0.360 0.041 13284 14090 10614 244 2.757 2.087 0.361 0.043 12949 13849 10297 245 2.782 2.086 0.361 0.043 13092 13936 10410 246 2.715 2.069 0.361 0.044 12982 13881 10357 247 2.740 2.089 0.361 0.045 12985 13929 10412 248 2.626 2.139 0.361 0.044 12951 13863 10313 249 2.512 2.092 0.362 0.044 12856 13734 10226 250 2.438 2.079 0.362 0.045 12558 13630 10073 251 2.410 2.069 0.362 0.046 12661 13602 10059 252 2.544 2.076 0.362 0.043 12790 13683 10149 253 2.630 2.086 0.361 0.043 12870 13744 10231 254 2.329 2.079 0.362 0.042 12865 13778 10275 255 2.112 2.070 0.363 0.046 12893 13828 10367 256 2.178 2.122 0.364 0.045 12794 13751 10239 257 2.219 2.141 0.364 0.045 12569 13603 10026 258 2.263 2.140 0.364 0.044 12557 13510 9899 259 2.280 2.143 0.365 0.041 12498 13433 9781 260 2.311 2.121 0.364 0.044 12205 13272 9610 261 2.312 2.140 0.364 0.043 12269 13371 9708 262 2.307 2.119 0.363 0.046 12562 13547 9968 CLS Single Level Calibration Using Etrans 1.462 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 48 263 2.408 2.136 0.363 0.046 12634 13636 10045 264 2.428 2.117 0.363 0.044 12641 13653 10058 265 2.341 2.106 0.363 0.047 12588 13570 9989 266 2.397 2.106 0.363 0.043 12487 13514 9949 267 2.384 2.107 0.364 0.043 12391 13346 9730 268 2.360 2.175 0.365 0.044 12243 13283 9606 269 2.329 2.169 0.365 0.044 12164 13216 9527 270 2.307 2.157 0.365 0.044 12283 13254 9605 271 2.302 2.186 0.365 0.043 12212 13306 9634 272 2.268 2.221 0.365 0.043 12323 13385 9730 273 2.429 2.577 0.368 0.042 12594 13592 9846 274 2.946 2.434 0.367 0.044 12772 13717 10019 275 2.842 2.269 0.366 0.046 12649 13568 9906 276 2.790 2.219 0.366 0.045 12538 13541 9915 277 2.745 2.234 0.366 0.043 12566 13528 9841 278 2.668 2.369 0.367 0.044 12464 13507 9770 279 2.589 2.419 0.367 0.044 12529 13544 9826 280 2.530 2.421 0.367 0.042 12664 13586 9912 281 2.546 2.475 0.367 0.042 12605 13598 9877 282 2.554 2.440 0.367 0.040 12676 13561 9847 283 2.531 2.403 0.367 0.039 12417 13419 9687 284 2.537 2.368 0.367 0.043 12220 13311 9598 285 2.554 2.662 0.370 0.043 12159 13326 9484 286 2.574 2.610 0.370 0.040 12273 13376 9514 287 2.592 2.680 0.371 0.041 12147 13304 9342 288 2.634 2.701 0.371 0.043 12453 13503 9624 289 2.759 2.664 0.370 0.044 12517 13533 9629 290 2.769 2.647 0.370 0.055 11491 13614 9759 291 2.804 2.698 0.371 0.060 11015 13464 9460 CLS Single Level Calibration Using Etrans 1.462 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 49 292 2.880 2.765 0.372 0.015 12459 13458 9305 293 3.004 2.837 0.372 0.007 12428 13492 9270 294 3.054 2.725 0.370 0.005 12651 13627 9653 295 2.848 2.550 0.368 0.003 12902 13821 10017 296 2.798 2.578 0.368 0.002 13053 13920 10146 297 2.817 2.510 0.367 0.002 13039 13929 10169 298 2.784 2.460 0.367 0.001 13211 13960 10279 299 2.783 2.424 0.366 0.002 13280 14036 10406 300 2.929 2.526 0.367 0.001 13631 14255 10651 301 2.920 2.524 0.366 0.000 13783 14414 10804 302 2.844 2.453 0.366 0.000 14028 14542 11020 303 2.847 2.413 0.37 0.001 14195 14697 11237 304 2.968 2.429 0.375 0.000 14398 14770 11343 305 3.053 2.434 0.376 0.000 14394 14823 11347 306 3.133 2.446 0.378 0.000 14543 14879 11412 avg 2.680 2.058 0.35 0.040 15531 15841 12719 std 0.703 0.182 0.011 0.009 1859 1402 1727 B 50 Attachment 3 Concentration Data from CLS Multilevel Calibration Using Etrans Reference Spectra B 51 CLS Multilevel Calibration Using Etrans 1.462 cm 1 Reference Spectra File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

2 2.364 2.295 0.355 0.047 15684 17435 13145 3 2.247 2.25 0.353 0.046 15897 17636 13343 4 2.172 2.200 0.352 0.043 15881 17743 13474 5 2.158 2.285 0.353 0.042 16189 17925 13597 6 2.209 2.226 0.352 0.040 16048 17873 13606 7 2.252 2.211 0.352 0.039 16226 17876 13590 8 2.321 2.253 0.353 0.040 16141 17892 13558 9 2.489 2.198 0.352 0.044 16247 17982 13634 10 2.554 2.193 0.351 0.040 16365 17953 13601 11 2.621 2.210 0.350 0.039 16341 17905 13566 12 2.537 2.216 0.349 0.038 16208 17936 13589 13 2.411 2.162 0.349 0.042 16344 18116 13782 14 2.367 2.209 0.349 0.043 16463 18155 13768 15 2.355 2.223 0.349 0.042 16534 18177 13761 16 2.332 2.163 0.347 0.041 16505 18173 13822 17 2.318 2.165 0.347 0.044 16423 18188 13864 18 2.319 2.153 0.346 0.042 16568 18275 13914 19 2.294 2.145 0.345 0.040 16659 18300 13991 20 2.358 2.138 0.344 0.042 16714 18403 13986 21 2.353 2.150 0.344 0.044 16709 18512 14006 22 2.246 2.142 0.343 0.041 16705 18379 13960 23 2.188 2.127 0.342 0.043 16792 18660 14041 24 2.244 2.122 0.341 0.043 16971 18789 14110 25 2.212 2.103 0.341 0.039 17142 18936 14190 26 2.085 2.064 0.339 0.040 17046 18799 14062 27 2.056 2.055 0.338 0.039 16924 18528 13982 28 2.048 2.040 0.338 0.039 16868 18480 13987 29 2.171 2.047 0.339 0.033 16921 18528 14013 30 2.126 2.052 0.337 0.042 16964 18565 14025 CLS Multilevel Calibration Using Etrans 1.462 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 52 31 2.153 2.040 0.338 0.035 16804 18224 13781 32 2.218 2.031 0.337 0.038 16839 18453 13975 33 2.061 1.995 0.337 0.038 16796 18306 13839 34 2.089 1.991 0.337 0.039 16654 18118 13663 35 2.056 1.997 0.338 0.028 16662 18118 13629 36 1.931 1.991 0.339 0.030 16480 17936 13516 37 1.970 1.995 0.338 0.033 16547 18114 13694 38 1.998 2.021 0.338 0.030 16869 18308 13838 39 1.967 2.034 0.338 0.032 16848 18359 13881 40 2.008 2.048 0.338 0.032 16891 18342 13896 41 1.885 1.987 0.338 0.029 16563 18029 13596 42 1.944 1.986 0.338 0.032 16647 18160 13775 43 1.965 2.019 0.337 0.038 16746 18250 13801 44 2.133 1.992 0.337 0.036 16831 18427 13980 45 2.145 2.028 0.337 0.032 17001 18577 14041 46 2.494 2.036 0.336 0.039 17036 18713 14042 47 2.406 2.028 0.336 0.042 16768 18339 13857 48 2.279 2.020 0.336 0.039 16605 18170 13671 49 2.218 1.996 0.337 0.039 16412 17956 13493 50 2.242 1.998 0.336 0.037 16767 18148 13666 51 2.235 2.027 0.337 0.029 16720 18226 13748 52 2.123 2.023 0.337 0.033 17052 18691 14056 53 2.089 2.031 0.336 0.037 16939 18589 14053 54 2.022 2.040 0.337 0.038 16773 18318 13861 55 2.092 2.031 0.336 0.038 16825 18360 13912 56 2.070 1.998 0.336 0.035 16856 18383 13924 57 2.054 2.029 0.335 0.039 16792 18433 13989 58 2.073 1.997 0.335 0.034 16927 18403 13937 59 2.125 2.037 0.336 0.034 16916 18441 13914 CLS Multilevel Calibration Using Etrans 1.462 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 53 60 2.323 2.032 0.335 0.037 16882 18469 13956 61 2.089 2.036 0.335 0.038 16820 18719 14088 62 2.035 2.041 0.337 0.037 17012 18829 14134 63 2.282 2.031 0.335 0.030 17079 18611 13994 64 2.317 2.053 0.335 0.034 17082 18540 13945 65 2.216 2.000 0.334 0.037 16900 18315 13784 66 2.340 2.023 0.334 0.039 16795 18295 13721 67 2.431 2.028 0.335 0.034 16680 18172 13647 68 2.285 2.050 0.335 0.035 16469 17983 13438 69 2.264 2.027 0.334 0.039 16528 17996 13493 70 2.279 2.018 0.335 0.040 16444 18015 13483 71 2.451 2.027 0.335 0.040 16634 18120 13585 72 2.428 2.029 0.335 0.033 16710 18080 13590 73 2.306 2.020 0.335 0.036 16555 18048 13538 74 2.317 1.997 0.335 0.035 16868 18251 13773 75 2.390 2.000 0.335 0.037 16742 18063 13564 76 2.362 2.021 0.335 0.036 16857 18286 13777 77 2.444 2.047 0.335 0.033 17034 18672 13985 78 2.510 2.020 0.335 0.035 16820 18351 13848 79 2.386 2.028 0.335 0.038 16523 18079 13547 80 2.324 2.077 0.336 0.037 16733 18242 13696 81 2.263 2.031 0.335 0.038 16508 18014 13480 82 2.260 2.038 0.335 0.038 16473 17969 13478 83 2.229 2.028 0.335 0.035 16719 18061 13531 84 2.376 2.026 0.335 0.035 16988 18469 13923 85 2.408 2.022 0.335 0.035 16905 18301 13786 86 2.186 2.027 0.335 0.038 16654 18129 13535 87 2.294 2.023 0.335 0.031 16801 18144 13581 88 2.126 2.023 0.335 0.029 16850 18196 13630 CLS Multilevel Calibration Using Etrans 1.462 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 54 89 2.068 2.026 0.335 0.028 16754 18232 13697 90 2.219 2.031 0.335 0.036 16662 18046 13476 91 2.454 2.038 0.336 0.035 16624 18062 13477 92 2.532 2.022 0.336 0.037 16719 18113 13553 93 2.620 2.028 0.335 0.036 16740 18146 13632 94 2.920 2.027 0.335 0.038 17026 18306 13745 95 3.115 2.025 0.336 0.038 16736 18218 13683 96 3.294 2.027 0.335 0.038 16882 18322 13773 97 2.968 2.026 0.335 0.040 16785 18235 13720 98 2.566 2.032 0.335 0.040 16748 18179 13646 99 2.653 2.030 0.336 0.037 16931 18269 13736 100 2.783 2.030 0.336 0.037 16830 18279 13764 101 2.696 2.025 0.335 0.039 16774 18208 13687 102 2.624 2.026 0.336 0.039 16813 18186 13703 103 2.680 2.032 0.336 0.040 16687 18111 13584 104 2.746 2.033 0.336 0.037 16665 18141 13629 105 2.861 2.033 0.336 0.038 16770 18142 13635 106 3.219 2.035 0.336 0.038 16679 18258 13719 107 3.945 2.037 0.336 0.037 16996 18482 13873 108 4.260 2.055 0.337 0.036 17141 18792 13915 109 4.028 2.043 0.336 0.036 17163 18718 13949 110 3.761 2.039 0.336 0.036 17108 18692 13968 111 3.669 2.036 0.336 0.038 17035 18677 13962 112 3.589 2.035 0.336 0.039 17090 18658 13967 113 3.689 2.053 0.337 0.038 17143 18826 14023 114 3.703 2.057 0.337 0.035 17243 18848 14050 115 3.766 2.064 0.338 0.040 17338 18956 14037 116 3.808 2.062 0.338 0.036 17245 19069 14113 117 4.061 2.067 0.338 0.038 17400 19269 14202 CLS Multilevel Calibration Using Etrans 1.462 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 55 118 4.386 2.067 0.338 0.037 17563 19335 14222 119 4.824 2.069 0.338 0.035 17648 19339 14248 120 4.874 2.067 0.339 0.036 17661 19364 14280 121 4.388 2.070 0.338 0.037 17635 19318 14260 122 4.052 2.080 0.339 0.034 17749 19347 14270 123 3.892 2.094 0.339 0.034 17627 19346 14299 124 4.202 2.102 0.339 0.036 17658 19389 14281 125 4.674 2.102 0.339 0.036 17758 19530 14351 126 5.284 2.093 0.339 0.036 17772 19677 14463 127 5.333 2.096 0.340 0.035 18045 19696 14517 128 5.307 2.096 0.340 0.035 17935 19675 14489 129 5.225 2.088 0.340 0.035 17868 19650 14493 130 4.833 2.087 0.340 0.034 17877 19662 14530 131 4.889 2.098 0.340 0.034 17982 19730 14567 132 4.842 2.096 0.341 0.033 17906 19697 14545 133 4.581 2.094 0.341 0.034 17956 19609 14489 134 4.397 2.094 0.340 0.036 17758 19562 14478 135 4.761 2.086 0.340 0.033 17843 19526 14478 136 5.522 2.083 0.340 0.034 17778 19541 14475 137 4.329 2.078 0.340 0.036 17174 19170 14251 138 3.552 2.087 0.340 0.034 17287 18991 14144 139 3.151 2.094 0.341 0.037 17303 19048 14215 140 2.753 2.080 0.342 0.039 16889 18525 14072 141 2.448 2.091 0.343 0.041 16778 18390 13968 142 2.574 2.084 0.343 0.039 16676 18267 13908 143 2.584 2.075 0.343 0.036 16637 18141 13763 144 2.546 2.074 0.343 0.040 16551 18118 13739 145 2.661 2.076 0.344 0.043 16555 18036 13647 146 2.703 2.083 0.345 0.042 16444 17912 13566 CLS Multilevel Calibration Using Etrans 1.462 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 56 147 2.705 2.096 0.346 0.043 16417 17857 13498 148 2.618 2.083 0.346 0.040 16377 17905 13583 149 2.571 2.084 0.346 0.039 16260 17829 13507 150 2.774 2.081 0.348 0.039 16152 17683 13362 151 2.779 2.080 0.348 0.040 16142 17596 13335 152 2.728 2.075 0.348 0.042 15929 17517 13226 153 2.604 2.075 0.348 0.043 15819 17365 13075 154 2.668 2.096 0.349 0.040 15755 17228 12995 155 2.670 2.085 0.349 0.041 15694 17177 12950 156 2.650 2.081 0.349 0.042 15678 17124 12895 157 2.454 2.089 0.348 0.041 15857 17173 12924 158 2.366 2.090 0.348 0.040 15583 17079 12839 159 2.278 2.093 0.349 0.039 15484 17004 12783 160 2.371 2.101 0.349 0.037 15480 16970 12744 161 2.492 2.116 0.350 0.040 15360 16903 12673 162 2.481 2.124 0.349 0.042 15493 16967 12684 163 2.498 2.168 0.348 0.041 15224 16761 12519 164 2.515 2.200 0.349 0.040 15199 16750 12481 165 2.482 2.130 0.349 0.040 15067 16804 12594 166 2.441 2.113 0.349 0.041 14864 16825 12626 167 2.424 2.114 0.350 0.043 15255 16850 12653 168 2.323 2.100 0.349 0.044 15219 16796 12607 169 2.295 2.113 0.349 0.044 15076 16773 12605 170 2.194 2.132 0.349 0.042 15211 16770 12587 171 2.075 2.180 0.349 0.041 15348 16765 12581 172 2.080 2.118 0.349 0.043 15169 16661 12509 173 2.232 2.125 0.350 0.044 14929 16315 12303 174 2.258 2.092 0.350 0.041 14820 16072 12208 175 2.097 2.110 0.350 0.042 15067 16504 12391 CLS Multilevel Calibration Using Etrans 1.462 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 57 176 2.056 2.120 0.349 0.041 15063 16515 12377 177 2.084 2.127 0.349 0.044 14954 16465 12358 178 2.156 2.121 0.350 0.041 14992 16411 12332 179 2.171 2.100 0.350 0.041 14904 16273 12255 180 2.046 2.171 0.350 0.041 14855 16109 12150 181 1.964 2.106 0.350 0.044 14908 16177 12210 182 1.962 2.096 0.350 0.045 14793 16243 12280 183 1.973 2.095 0.349 0.041 14897 16226 12262 184 2.059 2.133 0.349 0.043 14738 15862 12031 185 2.056 2.125 0.350 0.044 14561 15805 12000 186 1.972 2.102 0.349 0.044 14699 15877 12066 187 1.951 2.098 0.349 0.041 14671 16072 12179 188 1.913 2.117 0.349 0.041 15052 16527 12396 189 1.937 2.116 0.349 0.038 15075 16529 12393 190 1.985 2.118 0.349 0.040 15188 16712 12494 191 2.097 2.118 0.350 0.039 15212 16720 12541 192 2.243 2.124 0.349 0.043 15322 16812 12630 193 2.301 2.131 0.349 0.041 15391 16945 12713 194 2.303 2.148 0.349 0.045 15368 16920 12692 195 2.429 2.168 0.349 0.043 15336 16895 12592 196 2.940 2.160 0.349 0.043 15308 16946 12684 197 3.955 2.143 0.349 0.044 15450 16987 12644 198 4.159 2.143 0.348 0.041 15236 16762 12454 199 4.071 2.133 0.349 0.040 14940 16237 12113 200 3.372 2.124 0.350 0.041 14671 15862 12001 201 2.810 2.111 0.352 0.043 14306 15547 11793 202 2.657 2.106 0.353 0.042 14182 15446 11706 203 2.892 2.106 0.353 0.041 14210 15617 11861 204 2.711 2.096 0.354 0.039 14409 15662 11935 CLS Multilevel Calibration Using Etrans 1.462 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 58 205 2.491 2.101 0.354 0.042 14295 15481 11752 206 2.377 2.106 0.353 0.041 14069 15385 11648 207 2.269 2.109 0.354 0.044 14063 15292 11590 208 2.238 2.109 0.355 0.042 13633 14918 11158 209 2.265 2.112 0.356 0.042 13382 14643 10949 210 2.237 2.114 0.356 0.042 13213 14465 10739 211 2.204 2.118 0.356 0.040 13227 14491 10798 212 2.129 2.109 0.356 0.042 13334 14577 10861 213 2.118 2.108 0.355 0.043 13429 14637 10906 214 2.115 2.109 0.355 0.042 13404 14638 10934 215 2.090 2.136 0.356 0.043 13330 14516 10818 216 2.132 2.115 0.356 0.042 13253 14468 10794 217 2.156 2.116 0.356 0.041 13367 14558 10871 218 2.183 2.114 0.356 0.042 13215 14398 10733 219 2.155 2.112 0.356 0.044 13106 14254 10591 220 2.118 2.143 0.357 0.042 13088 14181 10497 221 2.185 2.188 0.358 0.040 12785 13845 10272 222 2.226 2.155 0.357 0.042 12681 13986 10346 223 2.342 2.154 0.357 0.040 12802 13797 10264 224 2.557 2.190 0.357 0.039 12942 14173 10445 225 2.606 2.182 0.356 0.042 13357 14558 10773 226 2.832 2.206 0.357 0.046 13095 14215 10435 227 2.713 2.201 0.357 0.044 12971 14134 10344 228 2.498 2.191 0.356 0.043 13130 14289 10521 229 2.691 2.187 0.356 0.044 13248 14421 10687 230 2.495 2.171 0.356 0.043 13082 14326 10592 231 2.508 2.151 0.357 0.038 13057 14275 10591 232 2.839 2.165 0.357 0.040 13177 14363 10657 233 3.220 2.170 0.356 0.046 12987 14342 10583 CLS Multilevel Calibration Using Etrans 1.462 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 59 234 4.074 2.185 0.355 0.042 13493 14748 10896 235 4.844 2.192 0.355 0.042 13626 14915 11025 236 4.142 2.211 0.357 0.043 13038 14234 10375 237 3.482 2.214 0.356 0.042 13073 14343 10457 238 3.384 2.208 0.356 0.043 13180 14427 10520 239 3.196 2.212 0.356 0.043 13253 14447 10576 240 3.121 2.186 0.356 0.044 13129 14363 10510 241 3.154 2.175 0.357 0.044 13103 14401 10497 242 2.924 2.171 0.358 0.043 12882 14107 10341 243 2.778 2.156 0.357 0.040 12667 13571 10138 244 2.745 2.167 0.358 0.041 12294 13181 9827 245 2.771 2.165 0.358 0.042 12419 13292 9936 246 2.703 2.148 0.358 0.043 12399 13221 9878 247 2.728 2.169 0.358 0.044 12342 13283 9930 248 2.610 2.221 0.358 0.043 12387 13198 9839 249 2.493 2.172 0.359 0.042 12162 13033 9742 250 2.418 2.158 0.359 0.044 11968 12900 9593 251 2.389 2.148 0.359 0.044 11912 12865 9580 252 2.526 2.155 0.359 0.042 12021 12968 9664 253 2.615 2.165 0.358 0.042 12223 13046 9754 254 2.307 2.158 0.359 0.041 12178 13090 9789 255 2.087 2.149 0.360 0.045 12246 13154 9876 256 2.154 2.203 0.361 0.043 12229 13055 9755 257 2.195 2.223 0.361 0.043 11977 12866 9551 258 2.240 2.223 0.361 0.043 11817 12749 9429 259 2.257 2.226 0.361 0.039 11784 12651 9316 260 2.289 2.202 0.361 0.043 11553 12446 9154 261 2.289 2.222 0.361 0.042 11639 12573 9246 262 2.284 2.200 0.360 0.045 11899 12795 9495 CLS Multilevel Calibration Using Etrans 1.462 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 60 263 2.387 2.218 0.360 0.045 11959 12908 9568 264 2.408 2.198 0.360 0.043 12038 12929 9582 265 2.319 2.187 0.360 0.046 11871 12824 9513 266 2.376 2.187 0.360 0.042 11809 12753 9476 267 2.363 2.188 0.361 0.042 11673 12540 9267 268 2.338 2.259 0.362 0.043 11586 12460 9152 269 2.307 2.253 0.362 0.042 11563 12374 9074 270 2.284 2.240 0.362 0.043 11592 12423 9150 271 2.279 2.270 0.362 0.041 11629 12491 9179 272 2.245 2.307 0.362 0.041 11632 12590 9267 273 2.408 2.680 0.364 0.041 11889 12853 9386 274 2.941 2.531 0.364 0.042 12113 13012 9558 275 2.834 2.357 0.363 0.044 11887 12822 9444 276 2.780 2.305 0.363 0.043 11873 12788 9451 277 2.733 2.320 0.362 0.042 11846 12771 9386 278 2.654 2.463 0.363 0.043 11713 12744 9318 279 2.572 2.514 0.364 0.042 11838 12791 9361 280 2.511 2.517 0.364 0.040 12011 12846 9444 281 2.528 2.573 0.364 0.041 11894 12860 9410 282 2.536 2.537 0.363 0.039 11833 12814 9381 283 2.513 2.498 0.364 0.037 11665 12633 9228 284 2.519 2.462 0.364 0.042 11511 12497 9142 285 2.535 2.769 0.367 0.042 11447 12518 9037 286 2.556 2.715 0.366 0.039 11597 12580 9070 287 2.574 2.789 0.367 0.040 11457 12489 8921 288 2.617 2.810 0.367 0.042 11696 12741 9190 289 2.746 2.772 0.367 0.042 11756 12778 9200 290 2.757 2.754 0.366 0.054 11023 12881 9322 291 2.792 2.808 0.367 0.059 10623 12692 9046 CLS Multilevel Calibration Using Etrans 1.462 cm 1 Reference Spectra ( Continued)

File CH4 CO N2O SF 6 H2O( 1) H2O( 2) H2O( 3)

B 61 292 2.870 2.877 0.368 0.013 11605 12684 8907 293 2.997 2.953 0.368 0.006 11629 12727 8881 294 3.051 2.835 0.367 0.003 11797 12898 9226 295 2.838 2.652 0.365 0.002 12090 13146 9564 296 2.788 2.681 0.365 0.001 12221 13272 9685 297 2.807 2.610 0.364 0.000 12257 13284 9709 298 2.773 2.557 0.363 0.000 12322 13324 9808 299 2.772 2.520 0.363 0.000 12475 13430 9926 300 2.923 2.626 0.363 0.000 12707 14006 10171 301 2.914 2.624 0.363 0.000 12872 14265 10323 302 2.836 2.567 0.363 0.000 13065 14439 10543 303 2.839 2.526 0.368 0.000 13233 14653 10766 304 2.963 2.543 0.372 0.000 13306 14754 10874 305 3.052 2.547 0.374 0.000 13420 14827 10877 306 3.134 2.561 0.376 0.000 13500 14904 10943 Avg 2.671 2.161 0.348 0.038 15095 16492 12328 Std 0.729 0.181 0.010 0.009 2035 2270 1784 B 62 Attachment 4 Concentration Data from Innovative Nonlinear Algorithm B 63 Concentration Values Reported from Innovative Nonlinear Algorithm File CH4 CO N2O SF 6 H2O CO 2 shift res 2 2.527 2.401 0.397 0.051 10684 520.1 0.52 1.486 3 2.404 2.344 0.396 0.050 10724 515.3 0.51 1.481 4 2.323 2.285 0.398 0.047 10902 510.9 0.51 1.487 5 2.306 2.399 0.399 0.046 10969 510.9 0.51 1.485 6 2.348 2.316 0.398 0.044 10894 509.1 0.51 1.483 7 2.393 2.295 0.397 0.043 10879 509.1 0.51 1.482 8 2.448 2.339 0.393 0.044 10684 509.7 0.51 1.475 9 2.612 2.269 0.393 0.047 10719 510.5 0.51 1.473 10 2.685 2.255 0.390 0.043 10546 510.0 0.52 1.466 11 2.746 2.268 0.388 0.043 10467 509.2 0.52 1.463 12 2.661 2.274 0.388 0.042 10464 509.5 0.52 1.462 13 2.520 2.202 0.387 0.046 10566 509.5 0.52 1.461 14 2.470 2.261 0.387 0.047 10552 509.9 0.52 1.460 15 2.451 2.278 0.385 0.046 10534 510.1 0.52 1.459 16 2.440 2.209 0.386 0.045 10527 510.0 0.51 1.459 17 2.417 2.212 0.384 0.048 10516 510.4 0.51 1.459 18 2.412 2.193 0.383 0.045 10525 510.4 0.51 1.458 19 2.383 2.186 0.383 0.044 10516 510.4 0.51 1.458 20 2.444 2.176 0.382 0.046 10546 510.0 0.51 1.458 21 2.431 2.188 0.382 0.048 10525 510.7 0.51 1.457 22 2.327 2.184 0.382 0.045 10490 510.0 0.51 1.457 23 2.258 2.160 0.381 0.047 10521 515.5 0.52 1.456 24 2.313 2.158 0.379 0.047 10535 529.3 0.52 1.455 25 2.276 2.112 0.379 0.043 10547 511.4 0.52 1.456 26 2.149 2.087 0.380 0.044 10485 501.1 0.52 1.455 27 2.108 2.071 0.379 0.043 10352 500.4 0.52 1.453 28 2.103 2.050 0.378 0.043 10347 499.0 0.52 1.454 29 2.215 2.062 0.378 0.036 10349 505.3 0.52 1.455 30 2.161 2.064 0.378 0.045 10297 498.2 0.51 1.453 Concentration Values Reported from Innovative Nonlinear Algorithm ( Continued)

File CH4 CO N2O SF 6 H2O CO 2 shift res B 64 31 2.199 2.050 0.378 0.039 10178 495.2 0.51 1.455 32 2.256 2.040 0.377 0.041 10256 495.9 0.51 1.454 33 2.096 2.024 0.379 0.041 10140 494.6 0.51 1.453 34 2.118 2.013 0.377 0.043 10032 494.2 0.51 1.453 35 2.097 2.024 0.378 0.031 10069 494.1 0.51 1.454 36 1.974 2.013 0.378 0.033 9997 494.1 0.52 1.453 37 2.010 2.014 0.377 0.037 10087 494.5 0.52 1.453 38 2.036 2.028 0.377 0.034 10191 497.4 0.51 1.453 39 2.003 2.039 0.377 0.036 10206 495.4 0.52 1.453 40 2.049 2.056 0.377 0.036 10194 491.1 0.51 1.453 41 1.923 2.012 0.377 0.032 10040 492.3 0.51 1.453 42 1.982 2.010 0.377 0.035 10100 490.9 0.51 1.454 43 1.996 2.027 0.376 0.041 10130 493.3 0.51 1.455 44 2.168 2.027 0.378 0.039 10214 492.9 0.51 1.454 45 2.181 2.046 0.378 0.035 10291 494.1 0.51 1.455 46 2.510 2.054 0.377 0.043 10246 497.4 0.51 1.454 47 2.418 2.049 0.377 0.045 10076 493.6 0.51 1.453 48 2.292 2.031 0.376 0.042 9955 493.2 0.51 1.453 49 2.233 2.023 0.377 0.042 9851 492.2 0.51 1.452 50 2.254 2.021 0.376 0.041 9958 492.4 0.51 1.451 51 2.259 2.032 0.376 0.033 10073 491.3 0.51 1.451 52 2.152 2.033 0.377 0.036 10263 491.2 0.51 1.451 53 2.105 2.035 0.376 0.041 10226 491.0 0.51 1.451 54 2.051 2.049 0.376 0.041 10107 490.7 0.51 1.450 55 2.114 2.042 0.376 0.041 10127 490.3 0.51 1.450 56 2.086 2.026 0.376 0.038 10103 492.7 0.51 1.451 57 2.043 2.041 0.376 0.043 10114 494.1 0.51 1.451 58 2.062 2.030 0.376 0.037 10066 495.6 0.51 1.449 59 2.121 2.053 0.376 0.037 10071 496.1 0.51 1.449 Concentration Values Reported from Innovative Nonlinear Algorithm ( Continued)

File CH4 CO N2O SF 6 H2O CO 2 shift res B 65 60 2.289 2.038 0.375 0.040 10082 494.7 0.51 1.449 61 2.051 2.054 0.376 0.041 10150 492.4 0.51 1.449 62 2.022 2.038 0.376 0.040 10207 491.5 0.51 1.450 63 2.277 2.041 0.376 0.034 10113 491.2 0.51 1.449 64 2.301 2.065 0.376 0.038 10033 491.5 0.51 1.449 65 2.207 2.025 0.375 0.041 9912 491.3 0.51 1.448 66 2.314 2.022 0.374 0.043 9864 491.8 0.51 1.446 67 2.406 2.035 0.375 0.038 9780 492.9 0.51 1.446 68 2.264 2.057 0.374 0.039 9668 494.8 0.51 1.445 69 2.240 2.030 0.374 0.043 9665 492.5 0.51 1.447 70 2.263 2.020 0.374 0.043 9682 491.7 0.51 1.447 71 2.426 2.032 0.374 0.043 9749 492.2 0.51 1.447 72 2.400 2.036 0.374 0.037 9751 491.8 0.51 1.448 73 2.283 2.023 0.375 0.039 9729 491.4 0.51 1.449 74 2.295 2.015 0.375 0.038 9861 491.5 0.51 1.449 75 2.370 2.021 0.375 0.041 9754 490.8 0.51 1.449 76 2.345 2.026 0.374 0.040 9888 491.2 0.51 1.448 77 2.426 2.061 0.375 0.037 10034 491.3 0.51 1.448 78 2.485 2.020 0.374 0.038 9895 491.4 0.51 1.446 79 2.368 2.029 0.373 0.041 9734 491.3 0.51 1.446 80 2.306 2.089 0.374 0.041 9813 491.2 0.51 1.446 81 2.245 2.034 0.374 0.041 9683 491.7 0.51 1.447 82 2.243 2.046 0.374 0.042 9652 492.2 0.51 1.449 83 2.214 2.033 0.374 0.038 9725 491.4 0.51 1.449 84 2.350 2.033 0.375 0.038 9929 491.7 0.51 1.448 85 2.377 2.026 0.374 0.039 9817 491.8 0.51 1.448 86 2.158 2.034 0.374 0.041 9668 492.0 0.51 1.447 87 2.263 2.024 0.374 0.034 9700 491.7 0.51 1.447 88 2.109 2.029 0.374 0.032 9782 491.9 0.51 1.449 Concentration Values Reported from Innovative Nonlinear Algorithm ( Continued)

File CH4 CO N2O SF 6 H2O CO 2 shift res B 66 89 2.044 2.027 0.375 0.031 9808 491.7 0.51 1.448 90 2.200 2.036 0.374 0.039 9683 491.9 0.51 1.449 91 2.428 2.043 0.374 0.038 9698 493.5 0.51 1.449 92 2.500 2.024 0.374 0.041 9749 493.7 0.51 1.448 93 2.590 2.032 0.374 0.040 9768 491.9 0.51 1.448 94 2.879 2.018 0.373 0.042 9874 493.0 0.51 1.447 95 3.074 2.026 0.374 0.041 9834 492.9 0.51 1.449 96 3.243 2.032 0.374 0.041 9890 493.2 0.51 1.449 97 2.924 2.025 0.374 0.043 9831 492.3 0.51 1.448 98 2.534 2.034 0.373 0.044 9773 491.5 0.51 1.448 99 2.621 2.042 0.376 0.041 9848 491.4 0.51 1.449 100 2.751 2.036 0.375 0.041 9864 491.7 0.51 1.450 101 2.656 2.031 0.375 0.043 9809 492.2 0.51 1.449 102 2.594 2.026 0.375 0.043 9816 491.6 0.51 1.449 103 2.650 2.029 0.374 0.044 9768 491.4 0.51 1.448 104 2.705 2.030 0.374 0.041 9779 491.5 0.51 1.447 105 2.814 2.033 0.374 0.042 9781 491.7 0.51 1.447 106 3.169 2.033 0.374 0.042 9856 492.7 0.51 1.447 107 3.879 2.040 0.374 0.040 9974 495.0 0.51 1.448 108 4.201 2.048 0.375 0.040 10073 496.4 0.51 1.449 109 3.975 2.049 0.375 0.040 10058 496.1 0.51 1.450 110 3.718 2.049 0.376 0.040 10066 495.5 0.51 1.450 111 3.624 2.046 0.375 0.042 10079 494.8 0.51 1.450 112 3.550 2.044 0.374 0.043 10081 494.3 0.51 1.451 113 3.643 2.045 0.375 0.041 10126 494.8 0.51 1.450 114 3.660 2.052 0.376 0.039 10154 494.5 0.51 1.451 115 3.731 2.060 0.376 0.044 10195 495.2 0.51 1.451 116 3.780 2.058 0.377 0.040 10249 496.5 0.52 1.452 117 4.032 2.065 0.377 0.042 10354 498.4 0.51 1.451 Concentration Values Reported from Innovative Nonlinear Algorithm ( Continued)

File CH4 CO N2O SF 6 H2O CO 2 shift res B 67 118 4.357 2.065 0.377 0.041 10410 499.6 0.51 1.451 119 4.803 2.068 0.378 0.039 10431 500.4 0.52 1.452 120 4.868 2.068 0.378 0.040 10456 500.7 0.52 1.452 121 4.382 2.070 0.377 0.041 10437 500.3 0.52 1.452 122 4.041 2.086 0.377 0.038 10475 501.6 0.51 1.453 123 3.875 2.104 0.378 0.038 10467 502.5 0.51 1.453 124 4.182 2.111 0.378 0.040 10507 504.6 0.51 1.453 125 4.663 2.107 0.377 0.040 10615 504.7 0.51 1.453 126 5.318 2.105 0.379 0.040 10714 504.7 0.51 1.454 127 5.381 2.106 0.379 0.039 10737 504.2 0.51 1.454 128 5.358 2.109 0.380 0.039 10732 504.3 0.51 1.454 129 5.273 2.099 0.380 0.039 10737 504.5 0.52 1.454 130 4.871 2.097 0.379 0.038 10751 503.3 0.51 1.454 131 4.937 2.107 0.380 0.038 10799 503.7 0.52 1.454 132 4.882 2.102 0.379 0.037 10792 503.8 0.52 1.454 133 4.632 2.103 0.379 0.038 10759 503.8 0.52 1.455 134 4.437 2.104 0.379 0.040 10722 503.5 0.52 1.455 135 4.813 2.092 0.379 0.037 10723 503.9 0.51 1.455 136 5.625 2.089 0.379 0.038 10747 504.1 0.51 1.456 137 4.341 2.082 0.378 0.040 10527 499.1 0.51 1.457 138 3.573 2.089 0.377 0.037 10420 495.6 0.51 1.456 139 3.181 2.097 0.378 0.041 10452 493.9 0.51 1.456 140 2.792 2.096 0.377 0.043 10381 497.1 0.51 1.457 141 2.503 2.114 0.379 0.045 10377 504.2 0.51 1.456 142 2.631 2.098 0.379 0.043 10315 501.5 0.52 1.456 143 2.639 2.091 0.379 0.039 10227 500.2 0.52 1.457 144 2.593 2.090 0.378 0.043 10217 501.6 0.52 1.456 145 2.726 2.091 0.378 0.047 10204 506.8 0.52 1.457 146 2.767 2.101 0.379 0.046 10150 513.1 0.51 1.457 Concentration Values Reported from Innovative Nonlinear Algorithm ( Continued)

File CH4 CO N2O SF 6 H2O CO 2 shift res B 68 147 2.770 2.111 0.378 0.046 10140 516.4 0.52 1.458 148 2.686 2.108 0.379 0.044 10181 518.5 0.51 1.459 149 2.641 2.108 0.379 0.042 10160 522.4 0.51 1.460 150 2.851 2.097 0.379 0.042 10102 535.6 0.51 1.460 151 2.857 2.091 0.379 0.043 10075 536.3 0.51 1.461 152 2.813 2.095 0.379 0.046 10022 533.9 0.51 1.461 153 2.680 2.091 0.379 0.046 9923 525.5 0.51 1.461 154 2.749 2.115 0.380 0.044 9860 533.2 0.51 1.462 155 2.749 2.102 0.380 0.045 9846 532.7 0.52 1.461 156 2.738 2.093 0.380 0.045 9836 530.1 0.52 1.462 157 2.547 2.103 0.380 0.044 9872 514.4 0.52 1.463 158 2.463 2.099 0.380 0.043 9817 512.3 0.52 1.462 159 2.366 2.103 0.380 0.043 9773 510.1 0.52 1.462 160 2.468 2.114 0.380 0.041 9762 520.2 0.52 1.461 161 2.579 2.128 0.379 0.044 9736 532.1 0.52 1.463 162 2.577 2.149 0.380 0.045 9748 535.4 0.51 1.461 163 2.595 2.198 0.379 0.045 9648 538.0 0.51 1.463 164 2.609 2.239 0.380 0.044 9654 534.9 0.52 1.462 165 2.582 2.148 0.380 0.043 9706 525.5 0.52 1.462 166 2.542 2.132 0.380 0.045 9738 534.9 0.52 1.463 167 2.521 2.139 0.382 0.047 9767 539.0 0.52 1.463 168 2.425 2.117 0.381 0.047 9738 532.2 0.52 1.463 169 2.403 2.134 0.381 0.047 9727 529.4 0.52 1.463 170 2.297 2.153 0.381 0.045 9728 524.3 0.52 1.463 171 2.168 2.216 0.381 0.044 9718 530.1 0.52 1.464 172 2.180 2.129 0.381 0.046 9662 528.5 0.52 1.462 173 2.334 2.141 0.380 0.047 9559 539.1 0.52 1.464 174 2.360 2.120 0.380 0.045 9490 540.5 0.52 1.464 175 2.201 2.123 0.380 0.046 9599 527.1 0.52 1.465 Concentration Values Reported from Innovative Nonlinear Algorithm ( Continued)

File CH4 CO N2O SF 6 H2O CO 2 shift res B 69 176 2.160 2.141 0.382 0.045 9594 523.2 0.52 1.464 177 2.187 2.143 0.381 0.048 9573 521.2 0.52 1.464 178 2.260 2.136 0.381 0.044 9563 519.6 0.51 1.465 179 2.282 2.129 0.381 0.045 9543 520.4 0.52 1.464 180 2.150 2.220 0.381 0.045 9498 520.5 0.52 1.466 181 2.067 2.136 0.381 0.047 9531 515.4 0.52 1.465 182 2.070 2.126 0.382 0.049 9560 516.2 0.52 1.465 183 2.078 2.125 0.381 0.044 9552 516.8 0.52 1.465 184 2.173 2.170 0.381 0.046 9421 530.4 0.52 1.465 185 2.172 2.157 0.381 0.048 9404 529.8 0.52 1.466 186 2.086 2.132 0.381 0.048 9458 520.0 0.52 1.466 187 2.065 2.128 0.381 0.045 9526 518.4 0.52 1.466 188 2.031 2.131 0.381 0.044 9639 507.1 0.52 1.465 189 2.050 2.132 0.382 0.041 9648 509.8 0.52 1.466 190 2.102 2.137 0.381 0.044 9709 510.6 0.52 1.465 191 2.219 2.140 0.382 0.043 9735 511.5 0.51 1.466 192 2.366 2.136 0.381 0.046 9798 509.4 0.52 1.465 193 2.427 2.154 0.381 0.045 9859 506.6 0.52 1.467 194 2.435 2.177 0.381 0.048 9847 506.4 0.52 1.467 195 2.557 2.192 0.381 0.047 9827 506.1 0.52 1.466 196 3.073 2.188 0.381 0.047 9859 506.0 0.52 1.465 197 4.122 2.165 0.382 0.047 9890 506.4 0.52 1.467 198 4.348 2.168 0.382 0.044 9808 514.2 0.52 1.467 199 4.267 2.176 0.382 0.043 9602 526.2 0.52 1.467 200 3.534 2.166 0.382 0.045 9478 528.7 0.52 1.467 201 2.950 2.144 0.380 0.047 9298 536.2 0.52 1.467 202 2.790 2.137 0.381 0.045 9243 540.4 0.52 1.467 203 3.046 2.140 0.382 0.044 9375 545.5 0.52 1.467 204 2.855 2.124 0.382 0.043 9414 546.3 0.52 1.468 Concentration Values Reported from Innovative Nonlinear Algorithm ( Continued)

File CH4 CO N2O SF 6 H2O CO 2 shift res B 70 205 2.638 2.133 0.383 0.045 9309 539.0 0.52 1.468 206 2.517 2.139 0.383 0.045 9250 533.3 0.52 1.468 207 2.398 2.138 0.383 0.047 9180 531.7 0.52 1.468 208 2.375 2.139 0.382 0.045 8948 544.0 0.52 1.468 209 2.393 2.134 0.383 0.045 8781 547.6 0.52 1.467 210 2.370 2.139 0.382 0.045 8702 548.2 0.52 1.469 211 2.340 2.142 0.383 0.043 8710 543.1 0.52 1.468 212 2.265 2.125 0.382 0.045 8774 536.3 0.52 1.468 213 2.255 2.125 0.383 0.046 8808 530.4 0.52 1.467 214 2.250 2.133 0.383 0.046 8821 526.4 0.52 1.469 215 2.230 2.160 0.383 0.046 8747 528.6 0.52 1.469 216 2.267 2.142 0.385 0.045 8726 528.1 0.52 1.470 217 2.293 2.137 0.384 0.044 8786 524.0 0.52 1.471 218 2.320 2.138 0.385 0.045 8695 529.3 0.52 1.470 219 2.297 2.143 0.385 0.047 8610 529.6 0.51 1.472 220 2.265 2.177 0.386 0.045 8595 525.5 0.51 1.472 221 2.336 2.231 0.386 0.043 8483 534.2 0.52 1.474 222 2.373 2.190 0.384 0.046 8522 532.3 0.52 1.472 223 2.492 2.188 0.384 0.043 8462 539.7 0.52 1.472 224 2.704 2.231 0.384 0.042 8569 537.6 0.52 1.471 225 2.755 2.220 0.384 0.045 8788 527.7 0.52 1.470 226 2.981 2.253 0.385 0.049 8594 538.1 0.52 1.471 227 2.871 2.251 0.384 0.047 8567 537.1 0.52 1.473 228 2.653 2.235 0.385 0.046 8646 525.2 0.52 1.471 229 2.850 2.226 0.385 0.047 8735 521.1 0.52 1.470 230 2.647 2.206 0.385 0.047 8676 524.2 0.51 1.470 231 2.670 2.181 0.385 0.041 8673 530.5 0.52 1.471 232 3.004 2.202 0.386 0.043 8711 532.9 0.51 1.470 233 3.396 2.208 0.385 0.049 8693 536.8 0.52 1.471 Concentration Values Reported from Innovative Nonlinear Algorithm ( Continued)

File CH4 CO N2O SF 6 H2O CO 2 shift res B 71 234 4.291 2.234 0.384 0.045 8915 537.6 0.52 1.470 235 5.124 2.243 0.385 0.045 9043 535.2 0.52 1.471 236 4.369 2.260 0.384 0.047 8649 545.8 0.52 1.472 237 3.664 2.266 0.385 0.045 8697 537.2 0.52 1.471 238 3.562 2.253 0.384 0.046 8754 532.8 0.52 1.470 239 3.367 2.260 0.385 0.047 8771 531.6 0.52 1.471 240 3.291 2.233 0.385 0.048 8735 537.9 0.51 1.471 241 3.322 2.215 0.385 0.047 8760 536.9 0.52 1.471 242 3.084 2.219 0.387 0.047 8589 539.0 0.51 1.472 243 2.947 2.218 0.385 0.043 8452 543.3 0.51 1.475 244 2.914 2.232 0.385 0.044 8238 556.0 0.51 1.475 245 2.945 2.228 0.386 0.045 8322 543.6 0.51 1.475 246 2.892 2.207 0.386 0.046 8295 543.3 0.51 1.476 247 2.900 2.225 0.384 0.047 8323 541.0 0.52 1.475 248 2.778 2.291 0.384 0.046 8264 536.8 0.52 1.475 249 2.665 2.227 0.385 0.045 8183 534.9 0.52 1.475 250 2.589 2.209 0.385 0.047 8100 538.7 0.52 1.475 251 2.557 2.197 0.385 0.047 8076 540.7 0.52 1.476 252 2.707 2.208 0.386 0.045 8142 538.8 0.52 1.475 253 2.803 2.221 0.385 0.045 8199 536.3 0.52 1.475 254 2.485 2.215 0.386 0.044 8237 537.9 0.51 1.476 255 2.261 2.205 0.386 0.048 8288 555.2 0.51 1.475 256 2.325 2.273 0.386 0.046 8217 557.9 0.51 1.475 257 2.371 2.298 0.386 0.047 8088 552.0 0.51 1.476 258 2.413 2.300 0.386 0.046 8021 558.3 0.51 1.477 259 2.428 2.312 0.386 0.042 7953 572.4 0.51 1.477 260 2.460 2.276 0.386 0.046 7825 568.9 0.51 1.478 261 2.464 2.301 0.386 0.044 7918 559.1 0.52 1.477 262 2.470 2.264 0.387 0.047 8060 540.2 0.51 1.476 Concentration Values Reported from Innovative Nonlinear Algorithm ( Continued)

File CH4 CO N2O SF 6 H2O CO 2 shift res B 72 263 2.568 2.285 0.387 0.048 8127 533.8 0.52 1.474 264 2.587 2.260 0.387 0.046 8154 531.9 0.52 1.476 265 2.495 2.246 0.387 0.049 8082 534.3 0.52 1.476 266 2.559 2.248 0.388 0.044 8038 533.6 0.52 1.476 267 2.548 2.255 0.388 0.045 7920 538.3 0.51 1.478 268 2.519 2.343 0.388 0.046 7872 538.0 0.51 1.479 269 2.485 2.338 0.388 0.045 7815 538.3 0.51 1.479 270 2.463 2.323 0.389 0.046 7848 537.6 0.51 1.479 271 2.458 2.361 0.388 0.044 7885 541.8 0.51 1.479 272 2.423 2.409 0.388 0.044 7941 540.9 0.51 1.479 273 2.575 2.917 0.389 0.044 8034 541.7 0.51 1.478 274 3.139 2.704 0.390 0.045 8166 544.4 0.52 1.475 275 3.036 2.469 0.389 0.047 8080 545.8 0.52 1.476 276 2.979 2.401 0.390 0.046 8067 540.1 0.52 1.476 277 2.929 2.421 0.389 0.045 8053 541.6 0.52 1.476 278 2.844 2.615 0.389 0.045 8004 556.1 0.52 1.476 279 2.761 2.684 0.389 0.045 8029 552.7 0.52 1.476 280 2.693 2.691 0.389 0.043 8081 554.9 0.51 1.477 281 2.720 2.769 0.388 0.044 8076 560.4 0.51 1.476 282 2.723 2.721 0.388 0.042 8048 555.5 0.51 1.477 283 2.703 2.668 0.389 0.040 7941 554.2 0.51 1.478 284 2.702 2.619 0.389 0.044 7874 553.3 0.51 1.479 285 2.719 3.052 0.390 0.045 7840 558.0 0.51 1.479 286 2.729 2.973 0.389 0.042 7896 567.4 0.51 1.478 287 2.745 3.077 0.389 0.043 7825 574.0 0.52 1.478 288 2.784 3.109 0.389 0.044 7981 580.4 0.52 1.477 289 2.904 3.053 0.389 0.045 7995 579.9 0.52 1.476 290 2.923 3.027 0.389 0.057 8077 578.8 0.52 1.476 291 2.949 3.107 0.389 0.062 7954 583.2 0.52 1.476 Concentration Values Reported from Innovative Nonlinear Algorithm ( Continued)

File CH4 CO N2O SF 6 H2O CO 2 shift res B 73 292 3.014 3.215 0.389 0.015 7932 588.1 0.52 1.477 293 3.133 3.334 0.388 0.007 7932 597.7 0.51 1.478 294 3.222 3.155 0.389 0.005 8064 583.6 0.51 1.477 295 3.011 2.890 0.389 0.004 8254 568.3 0.51 1.476 296 2.959 2.930 0.389 0.003 8324 566.9 0.51 1.476 297 2.987 2.831 0.389 0.002 8337 568.4 0.51 1.476 298 2.959 2.752 0.389 0.002 8369 569.2 0.51 1.476 299 2.960 2.703 0.388 0.002 8437 566.1 0.52 1.476 300 3.109 2.848 0.389 0.002 8556 562.9 0.52 1.473 301 3.109 2.849 0.390 0.001 8676 555.2 0.52 1.473 302 3.026 2.743 0.391 0.001 8790 551.0 0.52 1.473 303 3.025 2.682 0.396 0.001 8906 549.0 0.52 1.472 304 3.156 2.708 0.402 0 8964 545.4 0.52 1.471 305 3.248 2.715 0.404 0.001 9011 544.6 0.52 1.470 306 3.329 2.735 0.404 0.001 9069 545.3 0.52 1.473 average 2.758 2.208 0.382 0.041 9496 519.2 0.51 1.462 std 0.726 0.248 0.01 0.01 879 24.4 0 0.011 C i Appendix C FTIR Spectral Analyses Conducted by ARCADIS Geraghty & Miller ( David Natschke) C ii ( Intentionally Blank) C 1 ARCADIS Geraghty & Miller, Inc. P. O. Box 13109 Research Triangle Park North Carolina 27709 Tel 919 544 4535 Fax 919 544 5690 MEMO To: John Kinsey US EPA, APPCD From: Date: David F. Natschke 27 September 2000 Subject: Report on the Analysis of Open Path FTIR Data from the Chlor Alkali Plant Introduction EPA supplied two open path FTIR data sets. The first consisted of ten Iomega ® Zip disks that included . spc files. These files were single beam sample spectra collected by USEPA Region IV personnel.

The second data set consisted of 1 Fujitsu magneto optical ( MO) disk that included . spc files. These files were absorbance spectra " packed" as " multifiles" and consisted of upwind ( background) spectra collected by USEPA/ APPCD personnel, which had already been processed from raw interferograms to absorbance by EPA. The " spc" suffix indicates a data file format used by MIDAC, Galactic Industries, and others for spectral data.

The processing steps consisted of obtaining the appropriate software, file transfer and organization,

packing the individual files as multifiles, conversion to absorbance, unpacking the multifiles to individual absorbance files, processing through the AutoQuant ® program, and results organization. These steps are described in the following sections.

Obtaining the Software Two software packages were needed to accomplish this task: GRAMS/ 32 ® and AutoQuant ® .

GRAMS/ 32 ® was needed for the processing of the . spc files, while AutoQuant ® is the quantification package. GRAMS/ 32 ® is a Galactic Industries product that may also be obtained through MIDAC Corporation and other instrument manufacturers. AutoQuant ® is a MIDAC Corporation product. Both C 2 packages were obtained from MIDAC. The " non collect" version of GRAMS/ 32 ® was purchased, as this was sufficient for the task and slightly less expensive.

File Transfer and Organization Sample spectra were obtained as . spc files on 10 Zip disks. Arcadis found that the files were highly disorganized with many duplicates and files from sequential samples spread across multiple disks.

In a few cases, an individual file was completely missing. Many irrelevant files, unknown purpose, were also included.

The disks were manually cataloged to determine the location of sequential sample files and to identify missing files. A total of 1,964 unique data files from seven nominal sampling dates were identified.

Unique files were then transferred to hard disk and organized in directories by nominal sampling date.

These files were then archived to a recordable CD before any file manipulation was performed. The following table describes the number of sample files identified by sampling date.

Table 1. Samples by Date Prefix Sampling date prefix Number of sample files D0217 1 D0218 276 D0219 327 D0220 501 D0222 272 D0223 282 D0224 305 Packing Individual Files as Multifiles The spectra were in single beam format. While not critical, the conversion to multifile format is a tremendous time saver prior to calculation of absorbance spectra. The multifile format permits spectral arithmetic operations to be performed on all members of a multifile with a single command.

The first file manipulation performed was, therefore, packing as multifiles. GRAMS/ 32 ® was used for this conversion. As implemented there is a limit of 60 files that can be packed into a single file. For C 3 convenience, 50 files were placed in the typical multifile. These files were named with the sampling date prefixes described in Table 1 with the addition of a single letter suffix and then archived to a separate subdirectory on the hard disk.

Conversion to Absorbance Spectra must be converted to absorbance prior to any quantification, based upon the following equation:

Abs log I I0 =

     In this equation, I refers to the single beam spectrum while I0 is a reference spectrum.

In open path FTIR, it is difficult to obtain a true reference spectrum. The full optical path can rarely be contained and purged of all infrared active compounds. A number of techniques have been used to generate a useful reference spectrum. It is sometimes possible to obtain a valid upwind spectrum that is free from the compounds of interest. Another technique calls for the generation of a " synthetic background" spectrum, usually by taking a spectrum and removing all known spectral features from it.

The synthetic background spectrum is often generated manually, though it may also be generated by fitting some function, for example a spline function, to the baseline of the single beam reference spectrum.

EPA supplied a synthetic background spectrum for use with this data set. The generated multifiles were converted to absorbance using this reference spectrum. The absorbance multifiles were archived to hard disk in separate subdirectories.

Unpacking the Multifiles to Individual Absorbance Files Since AutoQuant ® cannot deal with absorbance multifiles GRAMS/ 32 ® was used to separate multifiles into individual files. The individual files were archived to hard disk. C 4 Processing through the AutoQuant ® Program AutoQuant ® requires one or more " method" files, the supporting calibration spectra with concentration data, and sample absorbance spectra. EPA supplied three method files and all the associated calibration spectra for use in the quantification of these data.

In use, a given method is calibrated with the supplied calibration spectra and then applied to the selected spectrum or spectra ( batch mode). For these calculations, three separate methods were needed.

Each was applied sequentially to the selected set of spectra. Results are in ppm. Results were archived to hard disk as . txt files.

Organization of Results The AutoQuant ® results were imported into Excel ® spreadsheets, 1 per sampling date, as multiple . txt files. Since AutoQuant ® does not maintain the original sample order in its results file, results were sorted within Excel ® by sample name ( number) to restore the original order.

The original sample date and time had been " lost" ( not transferred) by either GRAMS/ 32 ® during the conversions to and from multifiles or AutoQuant ® . Examination of individual absorbance files within GRAMS/ 32 ® shows that the sampling date and time are still attached internally after all manipulations were completed. The original sampling date and time were recovered by using the DOS command: dir >>

dir. txt within each of the single beam subdirectories. This ASCII file was then imported into the Excel ® spreadsheets and aligned with the results data. Printouts of these files are included with this memo.