Sensor purge heats the sensor to a high temperature, which evaporates excess molecules out of the sensor polymer. This minimizes the drift at the wet end of humidity readings, and removes contaminants from the sensor element. The heating phase is followed by a cooling phase where the sensor cools down to ambient temperature.
During sensor purge the values of the output parameters stay frozen at their last measured values. Sensor purge takes a few minutes to complete, after which measurement continues normally and updated values of output parameters are again available.
When ordered with sensor purge enabled, HMP model probes perform the purge at one day intervals (known as interval purge). If desired, sensor purge can also be performed when the probe is powered on (known as startup purge). Purge settings can be configured with the Insight software, the Indigo80 handheld indicator, or using the Modbus protocol.
|To allow the sensor purge to be completed in a reasonable time, it will not be started if the ambient temperature is below 0 °C (+32 °F).|