Vaisala HMT100 - Manual (Page 29)

Chapter 4 ______________________________________________________________ Maintenance
VAISALA _______________________________________________________________________ 29
3. Press the ADJ button on the transmitter motherboard. An indicator
LED lights up.
4. Insert the probe into the measurement hole of the LiCl salt
chamber. The indicator LED blinks evenly, indicating that the
measurement is changing.
5. Wait for 30 minutes or until the indicator LED stops blinking and is
lit continuously, which means that the measurement has stabilized.
6. Press the LiCl 11 % button to adjust the 11 % RH condition. The
transmitter returns to the normal operation mode, and the indicator
LED turns off.
7. To start calibrating the 75 % RH condition, press the ADJ button on
the transmitter motherboard again. The indicator LED lights up.
8. Insert the probe into the measurement hole of the NaCl salt
chamber. The indicator LED starts blinking.
9. Wait for 30 minutes or until the indicator LED stops blinking and is
lit continuously.
10. Press the NaCl 75 % button to adjust the 75 % RH condition. The
transmitter returns to the normal operation mode, and the indicator
LED turns off.
11. Replace the filter and the probe cover.
Adjustment with HM70
You can check and adjust the HMT100 relative humidity measurement
with the HM70 Hand-Held Humidity and Temperature meter. A HM70-
connection cable is needed. Vaisala order code: 211339.
There are four types of adjustments available: field checking and
adjustment using a calibrated reference probe, one-point adjustment
using a calibrator, two-point adjustment using a calibrator, and LiCl-
NaCl adjustment.
Follow the first seven steps and continue according to the chosen
adjustment method.
0505-351
Figure 14 Location of the MI70 Probe and Cable Connector
Ports