Humidity Sensor Hygromer CS 30: Linearity Data

Home Page | CS 30 Overview

Hygromer ^® CS 30: Linearity Data

Sensor Characteristic Response at 23°C

Linearity after calibration at 35 and 80%RH
The following table shows the deviation of the humidity signal from a perfect linear response when the sensor is associated with a linear electronic circuit. The data is valid at 23°C, after adjusting the circuit by exposing the sensor to 35 %RH and 80 %RH (offset and gain adjustment).

Rel. Humidity [%RH]	0	5	10	20	30	35	40	50	60	70	80	90	100
LDR - deviation [%RH]	-10.0	-5.5	-3.5	-1.5	-0.3	0.0	0.1	0.2	0.2	0.0	0.0	0.1	0.5

Example: the humidity output reads 18.5 %RH when the sensor is exposed to 20%RH.
Linearity after calibration at two values other than 35 and 80%RH
The linearity of the humidity signal depends on the choice of the two nominal humidity adjustment points by the circuit designer. When the humidity adjustment points are two values other than 35 %RH and 80 %RH, the linearity of the humidity signal can be derived from the 35-80 %RH table as follows: LD = (LDR – LDR1) – (LDR2 – LDR1) x (RH – RH1) / (RH2 – RH1) with: LD: linear deviation at the humidity RH [ %RH], after adjustment at RH1 and RH2 RH: actual value of relative humidity [%RH] RH1: first adjustment point – offset [%RH] RH2: second adjustment point – gain [%RH] LDR: linear deviation at the humidity RH [ %RH], as per the above table LDR1: linear deviation at the humidity RH1 [ %RH], as per the above table LDR2: linear deviation at the humidity RH2 [ %RH], as per the above table Example: linear deviation at 50 %RH, after adjustment of the sensor and associated electronics at 11.3 %RH and 75.3%RH (values that are not found directly in the above table are interpolated): (0.2 + 3.414) – (0.0 + 3.414) x (50.0 – 11.3) / (75.3 – 11.3) = 1.55 %RH When the sensor is exposed to 50%RH, the humidity signal reads 51.55 %RH Linearity – and measurement accuracy - can be improved by correcting the output signal either digitally or with an analog circuit.