M is for metric units, N is for non-metric units.
Parameter
Metric unit
Non-metric unit
RH
%RH
%RH
T
d
°C
°F
T
°C
°F
Examples:
unit
Units : Metric
unit
n
Units : Non metric
6.9 Calibration commands
6.9.1 Calibrate humidity measurement
Use the
CRH
command to perform a 1-point or 2-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:
• 1-point calibration with a single < 50 %RH reference will adjust the offset of the
capacitance measurement
• 1-point calibration with a single > 50 %RH reference will adjust the gain of the capacitance
measurement
• 2-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 1-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: 1-point calibration (LiCl reference, 11 %RH):
crh
11
OK
Example: 1-point calibration with NaCl reference (75 %RH):
HMP60 and HMP110 Series User Guide
M211060EN-J
46