This sensor module utilizes DHT11 as the sensitive component and has a bypass capacitor and a pull-up resistor on-board. The DHT11 is a pre-calibrated digital output temperature and humidity sensor. The single-wire wiring scheme makes it easy to be integrated into other applications. The simple communication protocol greatly reduces the programming effort required. These are bare temperature and humidity sensors. They are pinned Vcc, Data, NC (no connection), Gnd. They give readings roughly once per minute and are fairly accurate as they are factory calibrated. Output range: 20-90% humidity, 32-122 degrees F. It is inaccurate at either end of the spectrum, works pretty well in the middle of its range. Specifications: Operating Voltage: DC 3.3V - 5.5V, Humidity Measurement Range: 20%-95%RH, Humidity Measurement Accuracy: +/-5%RH, Temperature Measurement Range: 0 ~ 50 C, Temperature Measurement Accuracy: +/-2, Response Time: Less than 5s, PIN1-VDD: Power on 3.3V ~ 5.5V DC, PIN2-DATA: Signal output, PIN3-NC: NULL, PIN4-GND: External connection GND. Applications: HVAC, Testing and inspection equipment, Automotive, Data logger, Consumer goods, Automatic control, Weather station, Home appliances, Humidity regulator, Medical, Dehumidifier.