I noticed that our Purple Air’s temperature reading looked off this morning at 48 F. I checked it against another digital sensor located next to it, which read 33 F. I also looked at two nearby Purple Air sensors, less than 1/2 mi away and they both read 33F.
Looking at the graph of temperature over time for our sensor, I can see that the temp was falling, reached around 45F, jumped up by 15 deg F within one sample period, then kept falling.
This looks a lot like some kind of error that changed an internal offset, vs some kind of artificial warming of the unit. If I add the two nearby sensors to the graph, you can see that our sensor follows the same curve they do, just offset by 15 deg.
I’m seeing the same issue. One of my monitors had that jump in temperature and a drop in humidity, it looks like the adjusted values doubled. I guess this could have been due to some update?
Just wanted to piggyback on this issue — I just installed new outdoor and indoor monitors and both are hovering 10° or more higher than actual temps. Our indoor temp, for example, is controlled at 63° (currently measured at 62° with another thermometer at the PA monitor’s location), yet this monitor’s temp sensor is logging 76°at the moment on PA’s map. Similarly for our outdoor sensor.
Looking at surround PA sensors in our area, some are registering what would seem to be more accurate outdoor temps (40s) while others are also registering significantly higher temps (60s).
So, to any and all PurpleAir employees, why did some sensors leap up 8-15 F on March 16? Is there a workaround to calibrate these sensors to match all the other PurpleAir sensors? I have three sensors, and they DO NOT agree with each other.
Hi William, sorry for the mistake in my earlier comment. The email address was incorrect (I’ve edited and corrected it). You will want to use the email contact@purpleair.com. Rest assured that we’re looking into this.
Andrew,
Did you get my email to contact@purple.com sent March 21, 2023 at 5:10 pm PDT? Here is what it said:
Hi,
At your request, I am attaching two screenshots showing how on about March 16, the temperature jumped up about 12 degrees F, and the humidity dropped by a significant amount at the same time. This issue has persisted. My other sensors are unaffected.
Device address: [removed for privacy reasons]
Please let me know if there is a fix for this. And let me know if I can help further.
Providing an update on this issue. It is an issue with the driver change from BSEC to BSEC2 in firmware 7.03.
Non-VOC sensors are unaffected (BME280, which is present in the PA Classic), whereas VOC sensors are affected (BME680/BME688, which are present in PA Touch, PA Flex, and PA Zen).
This driver update was done as part of our improvement to the VOC readings on the sensors. As an aside, we are curious to know if any of our users are noticing an improvement in the VOC readings.
Nevertheless, we wanted to provide further details. We are looking into the source of the problem and expect to release a new version of firmware when we have found a solution.
We have identified the source of the issue. We will be rolling out firmware 7.04 soon, which will resolve the issue with the temperature and humidity readings. Thank you for your patience with us.
