Vaisala HMP42 - Manual (Page 26)

HMI41 AND HMP42
Operating Manual
M210317EN-A
22
RH
T °C
%
If the message “cal pass” does not appear (instead, some other text may
appear, e.g. “too close”, “err offst” or “err gain”), the correction has not been
stored in the memory. The error may be due to an incorrect reference value or
to measured values that are out of the range.
5.3.4 Two point temperature calibration
In two point temperature calibration, two accurate temperature references are
needed. Note that you must allow enough time for all instruments to stabilize
to the temperature equilibrium.
Start the calibration by inserting the probe to the lower reference temperature.
In setup mode, press ENTER repeatedly until the following is displayed:
set
Then press MODE five times, and the following appears:
set
T
Press ENTER to activate the two point temperature calibration mode. A
message similar to the following appears with the first line blinking:
set Lo
T
°C
The blinking number indicates the value of the lower temperature reference
stored in the HMI41 memory. Insert the probe to the lower reference
temperature. Check the reference temperature and change the display with
buttons ▲ and ▼ to correspond to the accurate value, for example: