Vaisala HMT360 User 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
=
=