AirGradient One Temp Accuracy

It seems my One displays 3-4 degrees warmer than any other temp sensor I have around it. Is there a way to calibrate or adjust the temp sensor?

This has been mentioned in another post with a blog article around the research that AirGradient is doing

You have not placed it above a heat source, like for example the usb adapter? This can easily throw it of by a few degrees.

I have three One (V9, pre-soldered kit) units sitting on a shelf near me while they await installation. They report the same temperature (within 0.2F difference) and the reported temperature is what I expect it to be (and verified roughly with an infrared thermometer). I’m pleased with their temperature sensor performance :slight_smile:

Thanks @kpfleming. Getting the temperature measurement right was actually one of the most difficult things in the design of the monitor due to internal heat sources in the enclosure.

Make sure you use the AirGradient upright mounted on the wall or use the stands. The correct temperature depends on a natural convection air flow through the enclosure.

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I have it on the stand. I had it on one bare wall first and then moved it recently closer to the same wall as the HVAC thermostat. While it’s not mounted on the wall, it’s about 2 feet away from thermostat, it currently shows 3 degrees different. While the HVAC thermostat is not governing authority on the real temp, I trust it’s temp reading. I will verify using other temp gauges just to be sure.

Have you changed anything in the software? The temperature sensor has an option to turn on a heater but usually that is not enabled by default.

The temperature/humidity sensor has a heater on it, so it can be used in condensing environments. Unfortunately, it also makes temperature readings way off.

You need to turn off the heater, and the accuracy will be back to normal (around ±0.2C). The heater defaults to “on” on some versions of ESPHome.

I have SHT4x Temperature and Humidity Sensor Module in Airgradient. How I can turn it off with YAML code?

If you are using ESPHome, and a reasonably recent version, the SHT4x heater defaults to ‘off’ already. See the docs at SHT4X Temperature and Humidity Sensor — ESPHome.

I think it was the SHT30 that had the change that had defaulted to the heater enabled for awhile, but was set back to disabled in 2023.10.x series
ESPHome 2023.10.0 - 18th October 2023 — ESPHome