The DMT132 is fully calibrated as shipped from the 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.
|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.|
|Ensure the pressure compensation setting matches the calibration environment before starting measurements and possible adjustments. For instructions on checking and setting the pressure compensation value, see Set Pressure Value for Dew Point Calculation.|
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 Vaisala Humidity Calibrator 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 dew point meter with a calibrated reference probe.
To have the transmitter calibrated and adjusted by Vaisala, contact a Vaisala Service Center or your local Vaisala representative.