Vaisala HM70 - Manual (Page 51)

Chapter 9 ______________________________________ Calibration and Adjustment of Transmitters
VAISALA _______________________________________________________________________ 49
23. Confirm by pressing YES
24. Press BACK, EXIT, EXIT to return to the basic display.
Calibration and Adjustment of HMT320 Series
Transmitters
You can check and adjust both humidity and temperature channels.
Make the temperature adjustment first in case you adjust both
channels. Calibrate your transmitter against a calibrated reference
probe of HM70 or against a calibrator's reference humidity by using
MI70 indicator in communication. Follow the first 8 steps and
continue according to the chosen calibration method.
1. Connect the 211339 -calibration cable to the RS232 connector in
the mother board of the HMP300-series transmitter
2. Connect the other end of the calibration cable to either of the
HM70's connector port located on the bottom of the indicator,
see Figure 7 on page 40.
3. Turn on both devices (the HMT300-series transmitter can be on
all the time).
4. The reading of the transmitter is shown on the first or middle
row of the display, depending on the connector port to which the
calibration cable is connected. Value of the port I is shown on
the upper row of the display and the value of the port II on the
lower row of the display. Difference of the readings is shown in
the lowest row.
5. Take off the CAL.DIS jumper from the motherboard of the
HMT300 transmitter. Now MI70 is moved into Adjustment
mode.
6. Press OK to start adjustment.
7. Select RH or T, press SELECT.
8. Check the environment settings, if needed. Otherwise press
NO.