Chapter 4 ______________________________________________________________ Maintenance
VAISALA____________________________________________________________________ 31
Offset and Gain Adjustments
Offset and gain adjustments are performed in the same way (they
differ only in internal calculations) so the following chapter is valid
for both methods.
4.
Connect the 25917ZZ HMI41-connection cable to the
SERVICE
PORT
connector on the HMT100 motherboard (see Figure 10 on
page 19).
5.
Connect the other end of the connection cable to the
EXT
connector located on the bottom of the HMI41 indicator (see
Figure 18 on page 29).
6.
Turn on both devices. Wait until the following display appears:
RH
7.
Select the appropriate adjustment mode with the
▲
and
▼
buttons. Select offset adjustment if the humidity is < 65 %RH
and gain adjustment if the humidity is
≥
65 %RH:
RH
or
RH
Press
ENTER
to confirm the selection. A display similar to the
following appears:
RH
%
The next sections describe how to perform offset and gain adjustments
in two different ways.
HMI41 as a Reference Meter
The HMI41 humidity probe is used to show the correct humidity value
(be sure that the reference probe has previously been adjusted).
Connect the cable and select the appropriate adjustment method as
previously explained and continue according to the following
instructions.
8.
A display similar to the one below should be visible:
RH
%
