Chapter 3 _______________________________________________________________ Calibration
VAISALA _______________________________________________________________________ 11
CHAPTER 3
CALIBRATION
There are four ways for calibrating the HMP230, HMT100 and
HMT330 series transmitters with HMI41. You can perform a one-
point offset or gain calibration using the HMI41 probe as a reference,
or you can use HMI41 only as a terminal. Alternatively, you can
perform a two-point calibration using the HMI41 probe as a reference,
or you can use HMI41 only as a terminal. Offset and gain calibrations
are performed in the same way and differ only for internal
calculations. Two-point calibration is more accurate, and includes
both offset and gain corrections. For performing a two-point
calibration, you need two separate measurement points with a
difference of at least 50 %RH between them.
NOTE
Two-point calibration is not supported for HMT100.
When the transmitter does not have a local keypad and it is calibrated
against salt solutions without a personal computer, HMI41 can be
used as a terminal for visualizing and setting the transmitter's RH
reading.
For a successful calibration, it is essential that the probe of HMI41
and that of the transmitter are at the same temperature, and that the
reference probe has been previously calibrated. Always allow enough
time for the readings to stabilize. Note that the stabilization time
depends on the ambient conditions and may vary from 10 minutes to a
couple of hours.
Getting Started
After having selected the desired function (Selecting HMI41
Calibrator Function on page 8) and checked the line settings, turn
Summary of Contents for HUMICAP HMI41
Page 36: ...www vaisala com M210777EN...
