PurpleAir Sensor FAQs

PurpleAir sensors are used to detect and measure air pollution in nearby areas, namely fine particulate matter (PM 2.5), smoke, and dust in the air. The sensors that APIFM is distributing are the PA-II Dual Laser Air sensors. To find out more about these sensors, please visit the PurpleAir website: https://www.purpleair.com/sensors.
  • Willingness to participate in the Clean Air SGV program and a community conversation about air quality.
  • An electrical outlet that allows the sensor to be installed on the outside of a building.
  • A flat surface where the air sensor can be mounted (with one screw).
  • Wifi access to get the sensor online.
  • Willingness to receive APIFM communications to maintain the sensor.
The air sensors are valued at approximately $259 each. Through grant funding from South Coast AQMD and SoCal Gas Company, APIFM is able to provide select participants with a free air sensor at no-cost as long as hosts agree to participate in the study and the Clean Air SGV program.
According to residents who are already hosting PurpleAir sensors, you should not be seeing a noticeable increase to your electricity bills.
The sensors need to be connected to your WiFi upon installation, but it should not slow down the speed of your WiFi.
The sensors are manufactured to report on outdoor air quality.
The sensor is yours to keep! We ask that the sensor be installed for at least two years but we would appreciate it if you could keep the sensor plugged in for as long as possible.
There is not a significant difference amongst the two, but we suggest to keep it on the second floor to prevent theft and vandalism.
The sensor will only show an approximate location of where it is based on it’s Wifi connection but will not display an address. All the air quality data collected will also be posted. The information and location of the sensor can not be turned off manually.

Yes! After installing the air sensors, you can track the air quality in your area on this website: https://www.purpleair.com/map?#1/11.4/-30.


  1. Open the PurpleAir link on your browser
  2. Click on the “Map” icon (located on the purple bar at the top of the webpage)
  3. On the top left hand corner, type in your location or the name of your sensor (ex. “SCAP_10”)
  4. Once the map locates your sensor, click on the circle icon to view the current air quality that your sensor is picking up
  5. Refer to the legend on the bottom left corner of the website. Make sure you toggle the downward arrow under the “Map Data Layer,” section to read , “US EPA Village Green,” which will give you the real time readings of the purple air sensors versus the generalized air quality index (AQI) readings which can be one of six federally regulated air pollutants (so the reading may not necessarily be based on PM levels) and these readings are not based on the last 24 hours since the data gathered is averaged over a longer period of time. Please visit: https://www.epa.gov/air-sensor-toolbox/what-do-my-sensor-readings-mean-sensor-scale-pilot-project for more information on what your sensor readings mean.

Yes, definitely! Anytime you will be doing prolonged activities outdoors you should check the purple air map and see where PM 2.5 levels have been at for the past hour. If the you are seeing readings that are medium-high it is advised you stay indoors or reduce the amount of time you are outdoors. For more detailed information please visit https://www.epa.gov/air-sensor-toolbox/what-do-my-sensor-readings-mean-sensor-scale-pilot-project and reference the FAQ section.

Please select “Public” when asked during the registration phase so that all the data collected on your monitor will appear on the Purple Air Map, otherwise your data collected will not be able to assist in our policy work in your community.
This is a personal preference but we suggest to install it closest to the street but behind a gate/fence to avoid the sensor being stolen. Thank you for your interest in hosting a PurpleAir Sensor and participating in the Clean Air SGV Project!