Humidity Sensor

Resistive Humidity Sensor

Humidity sensor works on the principle of relative humidity and gives the output in the form of voltage. This analog voltage provides the information about the percentage relative humidity present in the environment.

A miniature sensor consisting of a RH sensitive material deposited on a ceramic substrate. The AC resistance (impedance) of the sensor decreases as relative humidity increases.

The relative humidity is defined as:                       

The analog output of sensor is connected to ADC to get its corresponding digital value. For calibration of digital values, the reference voltage of ADC is set to 1.5 volts. The digital values are received   at port of microcontroller.  These digital values are used to calculate percentage relative humidity of environment. The calculated data is sent to LCD to display the   percentage relative humidity.

High sensitivity and reliability in a small package

Fast response time

High resistance to chemicals and contaminants

Enclosed in a moulded, cream coloured body

5mm pitch terminations

Technical Specification

AC resistance value 25°C	RH %	Value kΩ
	30	920
	40	220
	50	66
	60	23
	70	9.6
	80	4.2
	90	1.9
Humidity range	30 to 90% RH
Rated voltage	1.4 V AC pk
Rated power	0.26 mW pk
Frequency range	50Hz to 1kHz
Accuracy	±3% RH 60% RH, 25°C
Hysteresis	–3% RH 40-80% RH
Temperature dependence	0.5% RH/°C
Response time	60s
Operating temperature	0°C to +60°C