Vaisala MMT162 - Manual (Page 54)

User's Guide ______________________________________________________________________
52 __________________________________________________________________ M210934EN-C
MM70 in Checking and Adjusting
MMT162 can be checked and adjusted by using the MM70. In the field
you can check and adjust the probe's reading against the calibrated
reference probe of the MM70.
To check the MMT162 transmitter with MM70:
1. Connect the MMT162 to the MM70 indicator with the appropriate
connection cable (Vaisala item 219980).
2. Turn on the MM70.
3. Prepare the probe for adjustment by opening the adjustment menu
on the MM70 (Menu → Functions → Adjustments)
NOTE Make sure that both probes are stabilized to same conditions so that
the temperature readings are the same.
4. Press the OK key to start adjustment.
One-Point Relative Humidity Adjustment
Note that the humidity reference must be at least 50% RH. The MMT162
must be unpowered during stabilization which can take 30 minutes or
more.
Using Serial Line
To adjust the relative humidity:
1. Remove the filter from the probe and insert the probe into a
measurement hole of the dry end reference chamber (for example,
NaCl: 75 % RH in the humidity calibrator HMK15). Use the
adapter fitting.
2. Wait at least 30 minutes for the sensor to stabilize.
3. Connect the MMT162 to a PC, see section Serial Communication
on page 22. Then open a terminal program.
4. Enter the CRH command and press ENTER.
CRH
5. Type C and press ENTER a few times to check if the reading has
stabilized.