Sensor:
https://www.adafruit.com/product/2652
I recently purchased 11 Adafruit BME280 sensors (product ID 2652) that I have hooked up to Pi Zeros via I2C. All of them are pretty consistent in their humidity readings (around 40% in my case), but that is nearly 10% lower than all of my other hygrometers (Accurite, ExTech, Temp Stick, and Google Nest Thermostat). I don't have a problem with putting an offset in my code per se, but I'm not familiar enough with RH detection to know if there are issues with non-linearity or not.
Is this much of a difference possibly a defect in these sensors, something else? Would an offset (even as high as 10%) be sufficient at higher and lower RH? At $15 a pop, I'm honestly a little disappointed to have this kind of disparity. I didn't see any natively supported calibration method when searching online.
Thanks
PS: The temperature values are also consistently about 8 degrees (F) high; I think I read that this sensor uses the temp sensor to inform the humidity. Could that be related?
BME280 Sensor accuracy
Moderators: adafruit_support_bill, adafruit
Please be positive and constructive with your questions and comments.
- adafruit_support_bill
- Posts: 88093
- Joined: Sat Feb 07, 2009 10:11 am
Re: BME280 Sensor accuracy
Temperature and relative humidity are definitely related. The most important property of a sensor is repeatability. If you have a suitable reference to calibrate against, accuracy is attainable via calibration: https://learn.adafruit.com/calibrating-sensors
Please be positive and constructive with your questions and comments.