Having a few temperature sensors at my disposal, I made a big mistake: I compared the values they’re emitting.
From left to right we have here, in an area of 20 cm2, the following sensors:
- HTU21D, cost: $15
- XDK on loan; this is a pre-production unit, cost: $lots
- TI SensorTag CC2650, cost: $25
- DS18B20, cost: $10
- El cheapo is an inexpensive temperature and humidity display, cost: $21
- DHT11, cost: $5
Humidity is even more off than temperature:
The TI SensorTag CC2650 currently doesn’t feel like reporting humidity, so there!
Who actually calibrates these things? But much more importantly: how high is the temperature in my office?