Vaisala DMT132 - Manual (Page 57)

Chapter 5 ______________________________________________________________ Maintenance
VAISALA _______________________________________________________________________ 55
Humidity Calibration and Adjustment
(RHCAL)
The procedure below describes a humidity measurement calibration and
adjustment using the serial line commands and the Vaisala Humidity
Calibrator HMK15. You can use the procedure to do a one-point
calibration (offset) or a two-point calibration (offset and gain).
- To use the HMK15 humidity calibrator with the DMT132 you need
the special cover set for HMK15 (Vaisala order code 230914).
- One-point calibration requires a < 50 %RH reference
- Two-point calibration requires additionally a > 50 %RH reference,
with over 30 %RH difference between the two points.
NOTE Even though the transmitter outputs dewpoint, the humidity calibration
procedure is performed using relative humidity (RH) values. You can use
the Humidity Calculator to convert between dewpoint and relative
humidity. The Humidity Calculator can be found at:
www.vaisala.com/humiditycalculator .
1103-037
Figure 27 Calibrating DMT132 Using HMK15 and USB Cable