Vaisala HMT360N - Manual (Page 68)

User's Guide ______________________________________________________________________
66 __________________________________________________________________ M210744EN-C
Calculating Correspondence of Current Values
and Output Quantities
When using HMT360 without a display, calibration and adjustment is
carried out by using a multimeter. Use the following equations to
calculate the current values corresponding to the reference output
quantities.
0605-015
Example:
Temperature scaling -40 ... +120 °C, reference 22.3 °C:
0605-017
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.
where
Q
ref
= Reference value of the calibrated quantity
Q
min
= Reference value of the calibrated quantity
Q
max
= Value corresponding to 20 mA
I
4 mA 16 mA
Q
ref
Q
min
–
Q
max
Q
min
–
----------------------------- ⋅
+ =
I
4 mA 16 mA
22.3
° C 40° C
–
120
° C 40° C
–
--------------------------------------
⋅
+ 10.230 mA = =