The DHT22 is a popular, low-cost digital sensor for measuring relative humidity and temperature. It uses a capacitive humidity sensor and a thermistor, which are connected to an internal 8-bit single-chip computer to output a calibrated digital signal.
Features:
Dual Function: Measures both relative humidity and temperature in one package.
Calibrated Digital Output: Provides a fully calibrated digital signal.
High Accuracy: Delivers precise measurements with an accuracy of <±0.5°C for temperature and ±2%RH for humidity.
Wide Measurement Range: Capable of measuring temperatures from -40°C to 80°C and humidity from 0% to 100% RH.
Excellent Long-Term Stability: Highly stable with low drift, rated at ±0.5%RH per year.
Long Transmission Distance: The digital signal can be reliably transmitted over a distance of up to 20 meters.
Low Power Consumption: Efficient design ideal for battery-powered applications.
Specifications:
Parameter
Value
Model:
DHT22
Power Supply:
3.3V – 6V DC
Output Signal:
Digital signal via single-bus
Sensing Element:
Polymer Capacitor
Operating Range (Humidity):
0 – 100% RH
Accuracy (Humidity):
±2% RH (Max ±5% RH)
Resolution (Humidity):
0.1% RH
Operating Range (Temp):
-40°C to 80°C
Accuracy (Temp):
<±0.5°C
Resolution (Temp):
0.1°C
Repeatability:
±1% RH / ±0.2°C
Long-Term Stability:
±0.5% RH / year
Sensing Period (Average):
2 seconds
Dimensions:
25.1mm x 15.1mm x 7.7mm
Pinout:
Pin
Description
VCC
Power Supply
DATA
Digital Data Output
GND
Ground
Applications:
Home Automation and Smart Home Devices.
Personal Weather Stations.
HVAC (Heating, Ventilation & Air Conditioning) Systems.