Blog from December, 2020

TRH post calibrations

T and RH post calibrations were done (2020 Nov 11 and 2020 Nov 18, respectively) on all deployed sensors, so that there would be a record for posterity.  T data from SN 104 were not recorded, due to a LabView bug.  Also, the reference temperature was recorded in ohms, so I wrote code to convert it to degrees that might not be perfect.

All T data were great, with consistently slightly negative offsets, but still within -0.1 degC of the reference.

The RH data were not quite as good, with values high by up to 5%, but typically within 0.5 to 2.5%.  The largest errors were at cold temperatures (0 degC).  Errors at 20 and 40 degC were typically about 1%, or close to our specification.

Thus, T/RH data from SWEX20 are usable without correction – not bad for sensors left unattended for 9 months.  (Though there were fan issues...)