1188 Instruction Man DS5000.doc Page 4 of 16
The sensor is a variable capacitor, which is directly affected by changes in partial pressure of
water vapour, and these changes, that are proportional to the dew/frost point temperature, are
displayed on the instrument indicator.
The measuring sensor can be installed directly into the process line but this does create
problems with access for maintenance and calibration. It is for these reasons that we
recommend that the sensor be installed in a bypass, fast loop or total loss sample system
where the sensor is accessible without interrupting the main process flow line.
4.1 Piping installation Schematic
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4A
4B
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P
Main
Process
Line
Notes
a. The sample point should be on the upper surface of the horizontal pipe, or from a
vertical section of pipe, wherever possible.
b. The sample tube should run upwards from the sample point. If this is not possible,
then an inspection port or drain tap should be installed at the lowest point in the
sample system.
