Vaisala HMT360 - Manual (Page 66)

User’s Guide ______________________________________________________________________
64 ___________________________________________________________________ M010056EN-J
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 1:
Relative humidity scaling 0 ... 100 %RH, reference 11.3 %RH:
0605-016 Example 2:
Temperature scaling -40 ... +120 °C, reference 22.3 °C:
0605-017
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
11.3 %RH 0 %RH –
100 %RH 0 %RH –
------------------------------------------------- ⋅
+ 5.808 mA = =
I
4 mA 16 mA
22.3
° C 40° C
–
120
° C 40° C
–
--------------------------------------
⋅
+ 10.230 mA = =