I received the outdoor monitor a few weeks ago and the temperature is never close to correct. I tried using the default formula and custom offsets but even when I offset it to be correct, its way off come night time out day time. When using the default formula it’s usually 5 to 12 degrees Fahrenheit to warm. I have it attached to the side of my house under a covered porch. Sun light doesn’t shine directly on it.
I may have the same issue – I also get too-warm values from an outdoor unit, a pretty constant 3.5C. Two AirGradient indoor units are each 1C too high.
I had the outdoor sensor outside until it became obvious it was too high. I have a bunch of other sensors (uhoo, aranet4, six lumi sensors, two indoor airgradient and one outdoor airgradient). As a test they are now all sitting next to each other on a table inside. The non-airgradient sensors all agree within 0.5C.
Switching between “Standard AirGraident Open Air Calibration” and “Raw Data” has no apparent effect. Setting x 1.181 - 5.113 as a custom formula matches the “standard” calibration. I added a custom -1C offset to the two indoor airgradient sensors and a custom -3.4C offset to the outdoor sensor, which is clearly a hack, but brings the current reading in line with the others (currently 74F). The other thing I tried is unplugging the outdoor sensor for 20 minutes and plugging it back in. It comes back cool and warms back up over about 15 mins, which I think confirms the issue is electronics heating the unit.
I did my initial setup with the Home Assistant integration, now using app.airgradient. Is this a known issue? What else can I try?
On the Outdoor AirGradient that you have inside for comparison, it is raised up so airflow can happen under the device? just sitting on the table will cause false readings.
Similar with the indoor AirGradients, they should be upright using their stands or mounted to a wall. If laying flat on the back, it can impact readings due to heat building up inside of the enclosure.
If you used HomeAssistant first, it changes the configuration source to Local, so none of the AirGradient corrections are going to be in effect even if you change it on the Dashboard site. You can try changing it in Home Assistant under Settings>Devices>AirGradient and finding your device and changing it to Cloud
Then it will start using what you have configured in the Dashboard app site. If you want the Local configuration source, there are API calls you can make to enable it on the device.
How are you adding the custom offsets? Making a template sensor in Home Assistant so it gets a corrected value? Or anything else special you are doing?
Similar to the other poster on this thread, are you using Home Assistant integration? If so, it likely set the Configuration Source to Local which doesn’t apply the correction algorithms by default.
You could try changing the Source to Cloud in Home Assistant if applicable and see what happens
Thanks for the tips. I did start with Home Assistant, but before posting I found another forum post and added them to app.airgradient and set configuration to cloud – so that’s already taken care of.
I’m looking at the charts in HA, but the numbers match the numbers reported on app.airgradient, and I am changing the “Temperature Calibration Formula” there. I know it’s working because I can set a custom offset and I see it take effect everywhere.
I changed the mounting as you suggested – I have them all mounted to a vertical sheet of plywood now, a few inches apart from each other, a foot above the table. It didn’t significantly change the readings.
The big issue is the O-1PST’s temperature reading is about 6F too high and I can’t figure out why.
I turned off my custom adjustments so the two indoor units are set to “Raw Data” and the outdoor is set to “Standard AirGradient Open Air Calibration”. (Setting it to “Raw Data” gives the same numbers, which seems wrong…)
Here’s the three AirGradient sensors sitting next to each other:
At 11am I tried turned the O-1PST off for 15 minutes, then back on. It starts cold and heats up by about 12F.
I appreciate any ideas I can try.