Thanks @posburn! Yeah it appears PurpleAir map is discarding the bad value. I guess you could do something similar but might be interesting/tricky to determine when you are getting bad data from one of the sensors as you might not know if the lower or higher value is the bad value. PurpleAir might be looking at nearby sensors to help make this decision to decide which sensor is bad? My sensor has a confidence of 0 lol (rightfully so, one channel is completely off the charts). I tried blowing it out with pressurized air already but plan to open it up to try and blow it out a little better when I get a chance. Otherwise will be looking to buy a new sensor to replace.