Vaisala HMM212 - Manual (Page 26)

USER'S GUIDE____________________________________________________________________
Temperature Calibration
NOTE The temperature channel of the HMM212 is very stable and the modules
have been calibrated at the factory. Unless there is a strong reason to
believe that the adjustments have changed, do not perform a temperature
calibration. This is a very demanding procedure and requires both
expertise and extremely accurate references. Furthermore, it is important
to allow enough time for the stabilization during calibration. If for some
reason, it is necessary to perform the temperature calibration, follow
attentively the instructions given below.
Temperature Calibration of an RH and T
Module
- Allow enough time for the instruments to stabilize to the temperature
in which calibration is performed.
- Connect a DMM to the temperature current loop.
- Connect a jumper to the T offset or the T gain pins. Adjust the reading
with UP and DOWN switches (see Figure 5 on page 24). Note that
during gain adjustment, the offset point does not change:
Figure 6 Offset and Gain Calibration Examples
NOTE After having performed the calibration, disconnect the jumper.
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