Vaisala HMD60 Series - Calibration and Adjustment; Calibration and Adjustment Overview; Calibration and Adjustment Using Trimmers

7. Calibration and Adjustment
7.1 Calibration and Adjustment Overview
You can calibrate or adjust the transmitter's measurement output using one of the following
options:
• 1-point adjustment with the RH and T trimmers on the HMD60 component board
(adjustment range: -5%RH … +5 %RH and -0.3 °C … +0.3 °C (-0.54 °F … +0.54 °F).
• 1-point or 2-point adjustment by connecting the transmitter to Vaisala Insight PC software
(requires USB cable 219690).
• 1-point adjustment by connecting the transmitter to an MI70 hand-held indicator (requires
MI70 connection cable 219980SP).
7.2 Calibration and Adjustment Using Trimmers
HMD60 transmitters have 2 separate trimmers for RH and T measurement output adjustment
mounted on the component board. The trimmers allow for easy 1-point adjustment of the
measurement output against a reference with a known value.
The transmitters are shipped with the trimmers centered. Turning the trimmer counter-
clockwise decreases the measurement output value, and turning clockwise increases the value.
Figure 25 (page 34) shows the trimmer adjustment ranges for RH and T (-5 %RH … +5 %RH
and -0.3 °C … +0.3 °C (-0.54 °F … +0.54 °F).
±0 %RH
−1 %RH
−2 %RH
−3 %RH
−4 %RH
−5 %RH
+1 %RH
+2 %RH
+3 %RH
+4 %RH
+5 %RH
±0 °C
−0.06 °C
−0.12 °C
−0.18 °C
−0.24 °C
−0.3 °C
+0.06 °C
+0.12 °C
+0.18 °C
+0.24 °C
+0.3 °C
RH: −5 %RH ... +5 %RH T: −0.3 °C ... +0.3 °C
RH T
Figure 25 RH and T Adjustment Trimmer Ranges (Indicative)
The trimmers will only turn 135 degrees each way, less than half a rotation. Do not
force the trimmer past the stopping point.
HMD65 User Guide M212243EN-A
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