Fan-Aspirated MET4A Humidity Sensor Response Time

by Tim Potter

  Summary
A Fan-Aspirated MET4A Meteorological Measurement System was tested to determine the recovery time of the relative humidity sensor from 100% RH.  The measured relative humidity recovery time constant was less than 11 seconds.
  Test Method
The MET4A was placed into a humidity chamber.  Time-stamped relative humidity measurements were periodically taken until 100% RH was measured.  The MET4A was immediately removed from the chamber and relative humidity measurements continued until the measured RH values stabilized at room ambient humidity.

The test data was analyzed to determine the relative humidity recovery time constant, defined as the time required for a 63.2% change in measured RH.

  Results

Refer to Figure 1.  The graph demonstrates a measured relative humidity recovery time constant of less than 11 seconds.

 


Figure 1. Met4A Humidity Recovery Time

©2007 Paroscientific, Inc.