Calibration commands, Crh relative humidity calibration, Relative humidity calibration – Vaisala HMP230 User Manual
Page 90: Fcrh, Relative humidity calibration after sensor change
HMP230 SERIES
Appendix 1: Serial commands
M210225en-B
84
2.
CALIBRATION COMMANDS
CRH
Relative humidity calibration
Disconnect the security lock jumper!
CRH
With this command the transmitters can be calibrated against a reference. A
one-point calibration can be done against an accurate transfer standard in the
field and a two-point calibration using saturated salt solutions in controlled
conditions. A two-point calibration is performed as follows:
>CRH
RH
:
12.00
Ref1 ?
11.3
Press any key when ready ...
RH
:
76.00
Ref2 ?
75.5
In one-point offset correction, the Ref2 prompt is acknowledged with
>CRH
RH
:
12.80
Ref1 ?
11.3
Press any key when ready ...
RH
:
75.50
Ref2 ?
If the stabilization of the sensor to the humidity in the calibrator needs to be
monitored, the measurement output can be repeated by giving command c
at Ref1 and Ref2:
>CRH
RH
:
12.00
Ref1 ?
c
RH
:
11.70
Ref1 ?
c
RH
:
11.50
Ref1 ?
11.3
Press any key when ready ...
RH
:
76.00
Ref2 ?
75.5
FCRH
Relative humidity calibration after sensor change
Disconnect the security lock jumper!
FCRH
After humidity sensor change the transmitter must be calibrated using this
command and the calibration must be done at two reference points. The cali-
bration is performed as follows:
>FCRH
RH
:
1.90
Ref1 ?
11.3
Press any key when ready ...
RH
:
76.30
Ref2 ?
74.9