The HTU21D(F) is a new digital humidity sensor with temperature output. Every sensor is individually calibrated and tested.
It has a typical accuracy of ±2% with an operating range that's optimized from 5% to 95% RH. Operation outside this range is still possible but with reduced accuracy. The temperature output has an accuracy of ±1°C from -30~90°C.
The easiest way to use this sensor is to purchase it on a breakout board. These boardsare available from most hardware kit suppliers. The ones we used were purchased from Sparkfun and Adafruit and are shown above. The advantageof the Adafruit breakout board is that it has on on board voltage regulator so it can handle up to 5V. It also has a protective membrane over the sensor.
The supply voltage of HTU21D(F) sensors must be in the range of 1.5VDC - 3.6VDC. Recommended supply voltage is 3VDC (regulated).
The typical application circuit includes a pull-up resistor R on data wire and a 100nF decoupling capacitor between VDD and GND, placed as close as possible to the sensor.
Click on the image below to go to the Arduino to HTU21D hookup page.