Humidity Sensor HR202

The Humidity Sensor HR202 is a humidity-sensitive resistor: its resistance falls as the relative humidity of the air rises. It is small, low cost and responds within seconds, which makes it a good choice for humidity alarms, simple hygrometers and comparator-based humidity switches. It is also the sensing element used on the popular HR202 humidity detection modules.

Humidity Sensor HR202 Specifications

• Type: resistive humidity sensing element
• Humidity range: 20–95 %RH
• Operating temperature: 0–60 °C
• Accuracy: ±5 %RH
• Impedance: about 31 kΩ at 25 °C and 60 %RH (1 kHz, 1 V AC)
• Drive signal: AC only, up to 1.5 V AC, 500 Hz–2 kHz
• Response time: under 10 s

Humidity Sensor HR202 Applications

• Humidity alarms for storerooms, cupboards and server rooms
• Switching a fan or dehumidifier through a comparator and relay
• Greenhouse and incubator monitoring
• School science and sensor experiments

What's in the Box

• 1 × HR202 humidity sensor

Tip: Do not drive the HR202 element with plain DC for long periods, because polarisation shifts its reading; the datasheet calls for an AC signal. The resistance changes a lot with temperature too, so for calibrated %RH readings use a DHT22 or SHT-series sensor instead.

Orders placed before 14:00 are ready for pickup the same day. Delivery across Lebanon usually takes 1–3 working days.