Hi, my channel B went bad a while ago, and I finally got around to replacing the sensors with new ones. It’s all working fine, I see similar data between both A and B sensors. However, on the map it still shows “Laser counter channel B is downgraded. This is usually due to abnormal readings caused by faulty hardware or contamination with debris or insect.”
How do I get the map to know I’ve swapped out sensors and that they’re now both good? I’d like the confidence to move up from the 80% it is currently.
The sensor was still downgraded because it was manually downgraded by a PurpleAir staff member. When a laser counter is manually downgraded, it must be manually un-downgraded.
I agree that the sensor looks great and I’ve gone ahead and removed the downgrade. Everything on the map should be looking good.
My B sensor has suddenly dropped to 0% after being at 100% for a month or two after a cleaning of both lasers. I checked the fans, and they’re both working fine. Is it possible that you guys downgraded it from your end? It seems unlikely because I’ve had it set on Private for a week or so. Thanks.
I’ve found your sensor. We haven’t manually downgraded a channel, but it does appear that the system has automatically downgraded channel B in your device. Now, channel B has been experiencing some erratic behavior, so I think the downgrade is justified. However, downgrades do not affect the readings from channels, they only affect which readings appear in the sensor’s map marker.
You mentioned that you tried sensor maintenance and confirmed that both fans are working. Have you opened up the laser counters as you mentioned in a different community post?
Also I’ve just confirmed that your sensor is under warranty. Please reach out to contact@purpleair.com for replacement options.
Hi Kieran,
I just took it apart and cleaned it. There was a little dust on the receiver. It looks like it’s tracking the A channel OK now. This is the 3rd time I’ve done this to this sensor, and once to the A channel sensor. I’ve noticed there are 3 other monitors in my area with a downgraded B channel. Is this a coincidence, or is there some reason why it always seems to be the B channel that has problems? Thank you.
Hi Kieran,
The B sensor is doing better after I took it apart and cleaned it again, but it still seems to be misbehaving, and the match % is hovering between about 45 and 55%. I’ve got some tools coming in a few days, that will make it easier to take them apart for cleaning. I could try cleaning it again, but I wonder if it has a problem other than being dirty. After the previous times I cleaned it, the match progressively went back up to 100%.
You said my warranty is still good, but if it’s for one year, I think it ends in only another month or so. If you think there’s something wrong with the monitor and not just the sensor, I’d prefer a new monitor, before the warranty expires. If you think there’s something wrong with just the sensor other than being dirty, maybe you could just send me a new sensor. Or, I can try taking it apart and cleaning it again. What do you think? Thank you.
I have a similar issue. I recently ordered and received a pair of PA-2 PMS5003 from Purpleair and have installed them. They are tracking nicely from A to B and also with other nearby installations. But my map display still says my channel B is degraded. My station is
Sensor: 253 Military E
Regression for the past few days shows R2 > 0.99
Had it been manually degraded?
