Monitoring of Environmental parameters is necessary in so many ways. Not, just for different industries but also for common people. Both Higher and lower values of different environmental parameters are not sufficient for a normal being. Hence, there are different sensors that can help to get the readings of those parameters, including temperature and humidity. DHT22 is one of those sensors that get employed for temperature readings.
An Overview about DHT22 Temperature Sensor
DHT22 is more like the DHT11 sensor, but it has a richer measuring range and somewhat better accuracy. It uses exclusive digital-signal-collecting-technique and humidity sensing technology with greater reliability and stability. If you are looking to measure the temperature from the range of 40°C to 80°C, or want to estimate humidity from 0% to 100%, then this sensor might be a splendid choice for you.
Internal Structure and working Principle
The sensor comprises an NTC temperature sensor, i.e. thermistor, a humidity sensing component, and an IC on the backside of the sensor. A thermistor is basically a variable resistor (potentiometer) that changes its resistance with the change of temperature. And, to measure the humidity, there is a sensing element that has two electrodes with moisture-holding substrates between them. When humidity changes the resistance between these two electrodes gets changed.
Features and Specifications of DHT22 Sensor
Features
- Full range temperature compensated
- Relative humidity and temperature measurement
- Calibrated digital signal
- Outstanding long-term stability
- Extra components not needed
- Long transmission distance
- ow power consumption
- 4 pins packaged and fully interchangeable
Specifications
- Operating Voltage: 3.5V to 5.5V
- Operating current: 0.3mA (measuring) 60uA (standby)
- Output: Serial data
- Temperature Range: -40°C to 80°C
- Humidity Range: 0% to 100%
- Resolution: Temperature and Humidity both are 16 bit
- Accuracy: ±0.5°C and ±1%
Pinouts DHT22
| Pin number | Pin Name | Description |
| 1 | Vcc | The power supply pin requires voltage from 3.5V to 5.5V |
| 2 | Data | Output pin for both humidity and temperature through serial Data |
| 3 | NC | No connection Pin. This pin is not for connecting. |
| 4 | Ground | Connection of sensor to the system’s ground |
Applications of DHT11 Sensor
Weather Station
Because of the low cost of this temperature sensor, this can be used in cheap yet effective weather stations that can depict the environmental temperature and humidity which may help in various industries.
Climate Control
Climate control is a system for monitoring the temperature and other parameters. Therefore, the DHT22 temperature and humidity sensor may help to get the environmental readings to work accordingly.
Environmental Monitoring
An environmental monitoring system that monitors or controls the quality of the environment. Hence, this system also employs humidity and temperature sensors like DHT22.
