Vaisala HMT360 - Manual (Page 65)

Chapter 6 __________________________________________________ Calibration and Adjustment
VAISALA_______________________________________________________________________ 63
Connections
0505-293 Figure 25 Connecting Power Supply and Multimeter for
Calibration
1. Connect a power supply (12 ... 24 VDC, with a serial port the
minimum supply voltage is 15 VDC ) to the terminals B1 (-) and C1
(+) (Ch 1) with banana plugs, see
Figure 25 on page 63 .
2. Connect the multimeter in series with the supply, B1 (-) and A1 (+).
3. Follow the same procedure with Ch 2 using the terminals B2 (-) and
C2 (+). When calibrating both channels at the same time, use two
galvanically separated power supplies.
You can now calibrate or check the humidity and temperature or the analog
outputs according to the instructions given in this chapter.
If the current measurement is needed in a hazardous area, the multimeter
is connected to the terminals A1/A2 (+) and B1/B2 (-). Use only an
approved multimeter.
WARNING The power supply connectors (C1 and C2) MUST NOT be used in
hazardous areas. For calibration and adjustment in a hazardous area use
only an approved multimeter, which fulfills the safety factors printed on
the protective cover.
A1
B1
B2
A2
C1
C2
On
Off