Specifications

Synergy Nano Technical Manual, Revision -
Page 43
Vaisala Temperature Compensation
Vaisala Relative Humidity sensors are available in temperature compensated and uncompensated versions
and the Synergy Nano is compatible with both types. In addition the controller can accommodate sensors
with 0-5VDC and 4-20mA outputs.
The Synergy Nano uses the Vaisala recommended temperature compensation algorithm. The algorithm is a
second order polynomial defined over four temperature ranges by the following table of coefficients.
Where: a0, a1, b0, b1 are constants with the values as determined in the table below:
Vaisala Constants
Temp Range (C)
a0 a1
-40…-20 -0.104980 -0.060009
-20…+15 0.469374 -0.031292
+15…+45 0.000000 0.00000
+45…+180 -1.536460 0.034144
Temp Range (C) b0 b1
-40…-20 0.947370 -0.008510
-20…+15 1.050385 -0.003359
+15…+45 1.000000 0.000000
+45…+100 0.889657 0.002452
+100…+180 0.551922 0.005829
And Where:
Offset compensation: A = a0 + a1 * T
Gain compensation: B = b0 + b1 * T
The compensated RH value is:
RH Compensated = (RH Raw + A) * B