Vaisala MM70 - Manual (Page 47)

Chapter 5 ___________________________________________ CALIBRATION AND ADJUSTMENT
10. Enter the second reference humidity value by using the arrow
keys. Press the OK key.
11. Confirm by pressing the YES key.
12. To return to the basic display, first press the BACK key, then
the EXIT key twice.
Calibration and Adjustment of
MMT318 Transmitters
You can check and adjust MMT318 transmitter reading against a
calibrated reference probe of MMP78 or against another reference
condition by using MI70 indicator in communication. Follow the first
4 steps and continue according to the chosen calibration method.
1. Connect the DRW216050-calibration cable between the screw
terminal connector of the MMT318 transmitter and the MI70
indicator.
2. Turn on MM70.
- In case you use a MMP78 probe as a reference: 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 on the lowest row.
- In case MI70 is used as an display, the reading of the
MMT318 transmitter is shown on the display.
3. Remove the MMI318 transmitter unit from the mounting plate
and press the adjustment key once. Now MI70 is starting the
Adjustment mode.
4. Press the OK key to start adjustment.
Field Checking and Adjustment by
Using a Calibrated Reference Probe
When using this adjustment method, start with the steps 1 through 4 in
the section Calibration and Adjustment of MMT318 Transmitters on
page 45. Then proceed as follows:
VAISALA _______________________________________________________________________ 45