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Mounting the probes, Beware of temperature differences – Vaisala HMT310 User Manual

Page 23

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Chapter 3 _______________________________________________________________ Installation

VAISALA _______________________________________________________________________ 23

A

B

0507-035

Figure 4

Mounting Plate Dimensions

The following letters refer to Figure 4 above:

A = Larger mounting plate dimensions
B = Smaller mounting plate dimensions

Mounting the Probes

Do not unsolder and then again resolder the probe cable from the mother
board during installation; this may alter the humidity calibration of the
transmitter.

Beware of Temperature Differences

In humidity measurement and especially in calibration it is essential that
the temperature of the probe and the measuring environment is the same.
Even a small difference in temperature between the environment and the
probe causes an error. As the curve in Figure 5 on page 24 shows, if the
temperature is +20 °C and the relative humidity 100 %RH, a difference
of ±1 °C between the environment and the probe causes an error of
±6 %RH.