Vaisala DMT132 - Manual (Page 54)

USER'S GUIDE____________________________________________________________________
52 __________________________________________________________________ M211289EN-A
Calibration and Adjustment
The DMT132 is fully calibrated as shipped from factory. The
recommended calibration interval is 2 years in refrigerator dryer
applications. If the transmitter is used in the dry end of the measurement
range, calibration should be done every year. Calibration should also be
done if there is a reason to believe that the device is not within the
accuracy specifications.
NOTE For accurate calibration, disconnect the current loop from connector I for
the duration of the calibration. Power the transmitter using the USB
service cable (Vaisala order code 219690) instead.
NOTE If you have replaced the HUMICAP® 180R sensor, you should adjust the
capacitance measurement of the transmitter using the serial command
CRH
. For normal calibration and adjustment, use the RHCAL and CT
commands.
Performing a good calibration takes some time and preparation. Read the
HMK15 User’s Guide before performing your first calibration with the
HMK15.
You can perform a simple field checking operation by comparing the
readings of the DMT132 and the DM70 hand-held dewpoint meter with a
calibrated reference probe. For more information, see section Field
Check Using DM70 on page 53.
To have the transmitter calibrated and adjusted by Vaisala, contact a
Vaisala Service Center or your local Vaisala representative. See section
Technical Support on page 66.