Vaisala HUMICAP HMT360 SERIES - Calculating Correspondence of Current Values and Output Quantities

User’s Guide ______________________________________________________________________
62 ___________________________________________________________________ M010056EN-I
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° C40° C–
120° C40° C–
--------------------------------------
⋅+ 10.230 mA==