I see a red circle surrounded by green circles. Why is that?

The sensor could be experiencing pollution from a nearby source, such as a fire pit or chimney. The sensor could also be malfunctioning. While we try to remove data from malfunctioning sensors through our QC process, it is not perfect. Occasionally some low quality data will get through. One thing you can do to check is to look at the minute data on the “Instant” view. If you see a lot of spikes or really high values for a long time, then that sensor is probably malfunctioning. If that is your sensor, try to clean it out with some canned air.

Show All Answers

1. I see a red circle surrounded by green circles. Why is that?
2. Why are the Health and Instant views different?
3. What does the color scale mean?
4. What can I use the Health view for?
5. What can I use the Instant view for?
6. Why does your map look different from the map at purpleair.com?
7. Can I put a sensor on your map?