Make the Most of Radar  Following some best practices can ensure
accurate level measurement.  By Sarah Parker, Emerson Process
Management  Share Print Related RSS  The emergence of radar has
significantly advanced level monitoring. Radar provides cost-
effective and accurate measurements that are immune to density
and other process fluid changes, as well as most vapor-space
conditions.  Radar level measurement systems come in contacting
and non-contacting versions, both of which are widely applied in
the process industries. Contacting generally is a good fit for
small spaces; it easily replaces older technologies such as
displacers and capacitance probes. Non-contacting usually is
better for dirty, viscous or corrosive applications and when
agitators are present. Currently, contacting devices called
guided-wave radar (GWR) are slightly more prevalent, primarily
because they can measure interface level (e.g., oil and water)
as well as standard direct level (Figure 1).  There are some
important considerations wh