Manual adjustment, Low end adjustment (hmt360 without display) – Vaisala HMT360 User Manual
Page 69
Chapter 6 __________________________________________________ Calibration and Adjustment
VAISALA_______________________________________________________________________ 67
Manual Adjustment
This section contains separate manual adjustment procedures for
transmitters with and without display. You can perform the low-end
adjustment only (one-point adjustment), or adjust both low and high end of
the measurement (two-point adjustment).
Low End Adjustment (HMT360 without Display)
1.
Connect the power supply and multimeter as instructed in section
.
2.
Remove the filter and insert the probe into a measurement hole of the
reference chamber (for example LiCl: 11 %RH) in the humidity
calibrator.
3.
Power up the transmitter.
4.
Set the internal DIP switch Calibration Enabled/Disabled to
position ON and select RH calibration by using switches 3 and 4 (see
section
DIP Switch Functions on page 45
).
5.
The LED indicator will start blinking. According to the calibrator
used, wait at least 10 ... 15 minutes for the sensor to stabilize; use a
multimeter to monitor the stabilization.
6.
Press buttons Up and Dn to adjust the multimeter reading to
correspond the reference value (calculate the current value
corresponding to the reference humidity by using the equations
presented in
Calculating Correspondence of Current Values and
). Press button E to conclude the
adjustment.
7.
To continue with the high end (two-point) adjustment follow the
instructions in the next section.
If the low end adjustment is sufficient, press button E again to
conclude the calibration. Also restore the DIP switch settings; set the
calibration DIP switch to position disabled (down).
NOTE
If you use serial commands, please refer to section