Vaisala HMP110REF

User's Guide _______________________________________________________________________
48 ___________________________________________________________________ M211060EN-H
Calibration Commands
Calibrate Humidity Measurement
Use the CRH command to perform a one-point or two-point correction to
the capacitance measurement of the probe. This command changes the
offset and/or gain of the humidity measurement, depending on the
calibration and reference:
- one-point calibration with a single < 50 %RH reference will adjust the
offset of the capacitance measurement
- one-point calibration with a single > 50 %RH reference will adjust the
gain of the capacitance measurement
- two-point calibration will adjust both offset and gain. The first point
requires a < 50 %RH humidity reference, the second point must be
> 50 %RH. There must also be at least 30 percentage point difference
between the references.
CRH [reference]<cr>
This command is not available on the HMP110T.
When performing a one-point calibration, you need to place the probe in
the reference humidity and wait for 20 – 40 minutes for the humidity to
stabilize. To apply the adjustment, enter the CRH command with the
reference %RH as a parameter.
Example: one-point calibration (LiCl reference, 11 %RH):
crh 11
OK
Example: one-point calibration with NaCl reference (75 %RH):
crh 75
OK
Giving the command without parameters starts the two-point calibration.
Remember to allow the humidity to stabilize for 20 - 40 minutes after
changing the reference.
Example: two-point calibration with LiCl (11 %RH) and NaCL
(75 %RH) references:
crh
RH : 11.2684 1. ref ? 11
Press any key when ready ...
RH : 75.0612 2. ref ? 75
OK