This AM2302 temperature and humidity sensor also called DHT22 which is a high accuracy temperature and humidity sensor used in home conditions. It consists of a capacitive sensor element used for measuring relative humidity and a negative temperature coefficient (NTC) thermistor used for measuring temperature. Each sensor was calibrated in an accurate humidity room. Small dimension, ultra low power consumption, more than 20m's signal transmission distance make it a good selection for various application environment.The accuracy of this module can gets up to 0.3 degree in temperature and 2% in relative humidity.
Compared to the DHT11, this sensor is more precise, more accurate and works in a bigger range of temperature/humidity, but its larger and more expensive.