Field Check Using Dm70 - Vaisala HUMICAP DMT132 User Manual

DMT132 User Guide
If you have replaced the HUMICAPâ 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.
More Information
‣ Field Check Using DM70 (page 48)
‣ Technical Support (page 67)
5.4.1 Field Check Using DM70
To check the accuracy of the DMT132 in the field, you need the following equipment:
• A fully charged MI70 indicator (the measurement display that is included in the DM70
and HM70 hand-held indicator products).
• A calibrated reference probe that is suitable for the intended measurement
environment and dew point range.
• DMP74A probe from the DM70 is the recommended choice, as it offers the best
accuracy in the measurement range of the DMT132.
• All probes compatible with the DM70 and HM70 hand-held indicators may be used
as a reference.
• You can also use a second DMT132 transmitter.
• A connection cable between DMT132 and the MI70 indicator (Vaisala order code
219980).
• A reference environment with a stable dew point and temperature in a suitable range
for both devices. The normal measurement environment of the transmitter can also be
used, if it meets these criteria.
In the procedure below, the readings of the devices are checked individually. You can also
perform the field check so that you connect the reference probe simultaneously with the
DMT132 you are checking. In this case, you need two of the connection cables if you are
using a DMT132 also as the reference probe.
Make sure that the measurements are made in the same pressure.
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