Vaisala hmt120 - Figure 17 Location of the HMI41 Calibration Connector

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3
2
Figure 17 Location of the HMI41 Calibration
Connector
1 HMI41 indicator
2 25917ZZ connection cable
3 EXT connector
There are three adjustment modes available: oset (dry point), gain (wet point), and 2-point
adjustment. All of these can be performed using the HMI41 either as a reference meter (for
example when the transmitter is mounted in an air-conditioning channel), or only as a terminal
for visualizing and setting the transmitter's RH reading.
Oset and gain adjustments are performed the same way and dier only in internal
calculations. Select oset adjustment when the reference humidity is < 65 %RH and gain
adjustment when the reference humidity is ≥ 65 %RH. Two-point adjustment is more accurate,
and includes both
oset and gain corrections. For performing two-point adjustment, you need
two separate measurement points with a dierence of at least 50 %RH between them.
Start by completing the initial steps for connecting the HMI41 to the transmitter and selecting
the HMI41 calibrator function, and then continue according to the chosen adjustment method.
Chapter 6 – Calibration and Adjustment
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