Measurement of specific heat capacity cp

Measurement of specific heat capacity cp by Differential Scanning Calorimeter (DSC)

TSpecific heat or specific heat capacity CP describes the amount of energy that is necessary to heat up one kilogram of any material exactly for one kelvin.

There are substance with higher heat capacity like water, that need a considerable big amount of energy to be heated and others, like iron or lead that can be heated very fast due to their low heat capacity value. The exact determination of CP becomes interesting for fields like energy of heating, usage of waste heat, isolation, storage of heat or heat resistance of materials.

The CP value of almost every material that is used for construction is well known today and the determination has become more or less a standard requirement, beginning even in the research and development, where mostly only small amounts of testing material is available.

With DSC, the CP value can be determined on a very small sample amount of only some milligram, measuring against a sapphire disc in the recommended temperature range.

Sapphire is a material with linear behavior of its specific heat according to the temperature rise. This makes it an ideal calibration standard for this experiment. During a CP measurement, the sample is heated with a certain heating rate and at the same time the uptaken amount of heat is determined by comparison to the empty reference side of the DSC system.

Usually, if the sample does not undergo a phase transition or chemical reaction, the temperature of the sample should be a little bit beyond the ambient temperature of the specimen holder which is in this case the measured temperature of the empty reference site crucible. From this little difference, the exact amount of energy that was consumed by the sample during getting heated can be calculated using the sapphire calibration that was measured before.