Si7021 Highly Recommended!
The sensor should be plugged into the smart switch before power-on. It is not advised to plug or unplug the sensor after power-on. DS18B20 is waterproof, which can only measure temperature. Other sensors can measure both temperature and humdity.
With the eWeLink app, users can create simple conditional statement (Smart Scene) to trigger on/off other smart devices. This means users can use Sonoff TH10 or Sonoff TH16 with Si7021, AM2301, DS18B20 or DHT11 sensor to detect temperature/humidity, and then set specified temp. or hum. ranges as conditions to trigger on/off other smart devices in the same account, such as Sonoff Basic, Sonoff RF, Sonoff SV, S20. This device works perfectly with electric fan, air conditioner, humidifier, smart fish tank, watering system, etc.
Temperature and Humidity Sensor, No Waterproof