SGP/MET/E11 - Temperature/humidity sensor may have a cold and dry bias

The temperature/humidity sensor has not been calibrated since 4/7/2009. It has passed all 
but one 6-month field calibration check (failed reading high temperature 10/19/2009).

In comparison with a nearby Mesonet site, there is evidence of the sensor relative 
humidity reading lower than expected, especially in high humidity/nighttime situations. There is 
also evidence of a possible small cold bias in the temperature data. An exit calibration 
will characterize severity when the sensor is replaced. 

In general, the relative humidity may have been subject to drift during this time. The 
manufacturer characterizes sensor drift at <1% / year.

Please contact the mentor for specific information regarding the field calibration 

check results, if necessary.

• rh_mean
• vapor_pressure_mean
• temp_mean