SHT31-D High-Accuracy Humidity Sensor
Lab-grade Sensirion sensor for precision climate logging.
A high-accuracy I2C sensor from Sensirion used in HVAC and data-logging projects where DHT-series drift is unacceptable. The SHT31-D combines a capacitive humidity sensor and a bandgap temperature sensor on a single chip with factory calibration and onboard signal conditioning, delivering lab-grade accuracy and long-term stability that far exceeds cheaper hobbyist sensors like the DHT11/DHT22 — ideal for precision climate control, weather stations, and any project where measurement drift over time is a real concern.
Specifications
| Sensor type | Sensirion SHT31-D capacitive humidity + bandgap temperature sensor |
| Operating voltage | 2.4V–5.5V DC |
| Operating current | ~1.5 µA idle, ~600 µA during measurement (very low average power) |
| Humidity accuracy | ±2% RH typical (0-100% RH range) |
| Temperature accuracy | ±0.2°C typical (-40°C to +125°C range) |
| Response time | ~8 seconds (humidity, 63% response) |
| Interface | I2C, up to 1MHz (fast mode plus) |
| I2C address | 0x44 (default) or 0x45, selectable via the ADDR pin |
| Additional feature | Built-in heater element for condensation removal and self-diagnostics |
Pinout
| Pin | Name | Description |
|---|---|---|
| 1 | VIN | Power, 2.4–5.5V DC |
| 2 | GND | Ground |
| 3 | SCL | I2C clock line |
| 4 | SDA | I2C data line |
| 5 | ADDR | I2C address select — tie LOW for 0x44, HIGH for 0x45, useful when running two SHT31 sensors on the same bus |
Add standard 4.7kΩ pull-up resistors on SDA/SCL if not already present on the breakout board. The ADDR pin lets two SHT31 sensors share a single I2C bus at different addresses, which is handy for differential measurements (e.g. indoor vs outdoor) in the same project.
Variants
Choose the SHT31-D whenever measurement accuracy and long-term stability actually matter for the project — HVAC control, calibrated data logging, or anything where DHT-series drift would be a problem. For a casual weather display where a couple of degrees of drift is fine, the far cheaper DHT22 is an acceptable downgrade.
| Variant | Temp range | Hum range | Accuracy | Protocol | Price |
|---|---|---|---|---|---|
| SHT31-D breakout | ~$6-12 | ||||
| SHT35 | ~$10-18 | ||||
| DHT22 (AM2302) | ~$3-6 |