Vaisala Calibration of Series HMDW2030 and HMP130 Transmitter with HMI41 - Manual (Page 5)

HMI41 Calibration Option
19165ZZ-U220en-1.1 Operating Manual
1996-08-29 1
1. INTRODUCTION
1.1 HMI41 with calibration option
The HMI41 can be used as a field calibrator for various Vaisala humidity
transmitters. There are three different calibration cables available:
•
19116ZZ for the calibration of Vaisala’s HMD/W 60/70 and
HMP140 series analogue transmitters
•
19164ZZ for the calibration of HMP230 series digital transmitters
•
19165ZZ for the calibration of the HMD/W 20/30 and
HMP130 series analogue transmitters
In this manual, only the calibration of HMD/W 20/30 and HMP130 series
analogue transmitters is dealt with. For other calibration options, please refer
to corresponding manuals.
Calibration is quick and easy to perform. In calibration, the HMI41 measures
relative humidity with the reference probe and receives the RH information
from the transmitter. These two values are then compared on the HMI41
display and the transmitter is adjusted with calibration potentiometers inside
the transmitter.
1.2 Selecting the HMI41 calibrator function
The desired calibrator function is selected in the HMI41 setup menu. To enter
the setup mode, first press the ON/OFF button and the following appears:
RH
setminmax hyst hold Lo batHi
P Pa h g/m
T
Td °C °F
°C °F
%
Then release the ON/OFF button and within 1...2 seconds press both ENTER
and MODE buttons until the following text appears on the display:
After a few seconds, the text changes automatically to show the following: