When air is cooled, the temp at which condensation takes place
is termed the Dew Point (DP). A simple method of determining the DP is to cool
the air around a highly polished surface and cooling it. When the DP is reached,
condensation on this surface makes it cloudy and the temp observed at this point
is the DP. In our Dew Point Measurement System, cooling is done by dry ice (
solid CO2) in a polished tube and temp is measured by a Digital Temp Indicator.
This system can be used whenever periodic checking of dew point is required.
For continuous, online measurement system, the DP is determined by measuring
change in capacitance of special sensor placed in the air stream. This change is
transmitted to a device which displays the DP directly. This System is very
expensive and is generally installed in Air Dryers for critical applications.