From Micro Ohm's description

DHT22 Digital Temperature and Humidity Sensor Module AM2302 Black Board If you are wandering to build a device that detects temperature and humidity from the atmosphere, then This sensor is needed for you. you can Purchase this sensor from Micro Ohm at a reasonable price. The DHT22 Digital Temperature and Humidity Sensor Module AM2302 is a basic, low-cost digital temperature and humidity sensor. It uses a capacitive humidity sensor and a thermistor to measure the surrounding air and spits out a digital signal on the data pin (no analog input pins needed). It’s fairly simple to use but requires careful timing to grab data. The only real downside of this sensor is you can only get new data from it once every 2 seconds, so when using our library, sensor readings can be up to 2 seconds old. Simply connect the first pin on the left to 3-5V power, the second pin to your data input pin, and the rightmost pin to the ground. Although it uses a single wire to send data it is not Dallas One Wire compatible! If you want multiple sensors, each one must have its own data pin! Features : High precision Capacitive type Full range temperature compensated Relative humidity and temperature measurement Calibrated digital signal Outstanding long-term stability Extra components not needed Long transmission distance Low power consumption 4 pins packaged and fully interchangeable Package Includes : 1 x DHT22 Digital Temperature and Humidity Sensor Module AM2302 1 x Connecting Cable Model AM2302 Operating Voltage 3 ~ 5.5V Accuracy resolution 0.1 Humidity range 0-100%RH Temperature range -40~80°C Humidity measurement precision ±2%RH Temperature measurement precision ±0.5°C Length (mm) 43 Width (mm) 15 Height (mm) 10 Weight (gm) 7 Shipment Weight 0.01 kg Shipment Dimensions 5 × 4 × 2 cm DHT22 DATASHEET

From Most Electronic's description

DHT22 Digital Temperature and Humidity Sensor is a high-quality electronic component designed for Arduino, prototyping, and educational electronics. Description The DHT22 Humidity / Temperature Sensor Module uses a 1-wire interface to report both humidity (0 – 99.9%) and temperature (-40 – 80°C). PACKAGE INCLUDES: DHT22 Humidity / Temperature Sensor Module 3 x Female / Female jumper cable for connecting the module to a microcontroller. KEY FEATURES OF DHT22 HUMIDITY / TEMPERATURE MODULE: Reports humidity over range of 0% to 99.9% Reports temperature over range of -40°C to 80°C Uses 1-Wire interface 3.3 and 5V logic compatible This module utilizes the DHT22 which is a combined humidity and temperature sensor assembly. Note that AM2302 is just another name sometimes used for the DHT22 and you may see this marking on the module. The DHT22 sensor is capable of reading humidity over the full range of 0 to 99.9% with an accuracy of +/- 2% and temperature over the range of -40 to 125°C with an accuracy of +/- 0.5°C. The humidity accuracy increases to +/-5% at temperature extremes. The device does have a minimum sampling time of 2 seconds so the sensor cannot be polled more often than every 2 seconds or bad data may be retrieved. Module Connections The module has a 3-pin header on the assembly. 1 x 3 Header ‘+’ = Connect to 3.3V to 5V. OUT = Digital sensor I/O – Connects to a digital pin on a microcontroller ‘- ‘ = Connect to system ground. This ground needs to be in common with the microcontroller. The sensor is written and read via a single digital pin and requires the use of a library for the communications. With an Arduino, the DHTLib library can be downloaded from the Arduino site or GitHub. Parameters of the temperature and humidity sensor DHT22 Sensor AM2302 (DHT22) Supply voltage: from 3.3 V to 5.5 V Average current consumption: 0.2 mA Does not require additional external components 3 x female-female wires – included Module dimensions: 44 x 16 x 10 mm Temperature Measurement range: -40 to +80°C Resolution: 8-bit (0.1 °C) Accuracy: ± 0.5 °C Response time: on average – 2 seconds Humidity: Measuring range: 0 – 99.9 %RH Resolution: 8-bit (±0,1 %RH) Accuracy: ±2 %RH* Response time: on average – 2 seconds Details in the documentation . *RH – relative humidity is expressed in percentages. It is the ratio of actual humidity in the air to the maximum number that air can keep at a given temperature. It’s perfect for DIY makers, students, and anyone building custom electronic circuits or STEM kits.

From Future Electronics Egypt's description

This is DHT22 is a digital temperature and humidity sensor. It uses a capacitive humidity sensor and a thermistor to measure the surrounding air, and spits out a digital signal on the data pin (no analog input pins needed). Compared to the DHT11 , this sensor is more precise, more accurate and works in a bigger range of temperature/humidity. Features 3 to 5V power and I/O. 2.5mA max current use during conversion (while requesting data). Good for 0-100% humidity readings with 2-5% accuracy. Good for -40 to 125°C temperature readings ±0.5°C accuracy. 0.5 Hz sampling rate. Temperature and humidity sensor arduino code and how to connect . DHT22 Temperature and humidity sensor datasheet .