PurpleAir sensors use a laser particle counter to count the number of airborne particles in the air. That count is used to calculate a mass concentration, assuming an average particle density in an algorithm developed by the laser counter manufacturer, Plantower.
What sensors does PurpleAir use?
PurpleAir uses PMS5003 and PMS1003 laser particle counters. These sensors count suspended particles in sizes of 0.3, 0.5, 1.0, 2.5, 5.0, and 10um. These particle counts are processed by the sensor using a complex algorithm to calculate the PM1.
How accurate is PurpleAir?
Raw Purple Air data are about two times higher than the real values. We know this from placing Purple Air sensors at our regulatory monitors and comparing measurements. There are two important considerations when looking at Purple Air data to ensure the data is accurate: The data need to be calibrated.
What is purple on the air quality scale?
| Daily AQI Color | Levels of Concern | Values of Index |
|---|---|---|
| Yellow | Moderate | 51 to 100 |
| Orange | Unhealthy for Sensitive Groups | 101 to 150 |
| Red | Unhealthy | 151 to 200 |
| Purple | Very Unhealthy | 201 to 300 |
How does PurpleAir get its data?
Users of PurpleAir can toggle between real-time data and readings averaged over the last 10 or 30 minutes. The data comes from the commercial sensors the company sells, which members of the public install on porches, yards and other neighborhood sites.
What is Lrapa PurpleAir?
LRAPA has deployed a network of low-cost air quality Purple Air sensors throughout Lane County. The Purple Air sensors provide particulate matter (PM) data in communities without regulatory monitors.
Why is PurpleAir different than AirNow?
Why does the AirNow Fire and Smoke Map look different than the PurpleAir Map? … AirNow identifies potentially malfunctioning sensors based on a comparison of readings from the two fine particle sensors each PurpleAIr sensor contains, or from user reports.
How long do PurpleAir sensors last?
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.
What AQI is unhealthy?
An AQI over 150 is considered unhealthy for the general population. AQI over 101 can be unhealthy for sensitive groups and some workers with asthma and other conditions may feel unhealthy when the AQI is below 150.
What is the best site for air quality?
There are a lot of websites that offer a similar set of features without installing anything. Two you should try are BreezoMeter and Aqicn. Both of them provide largely accurate results. As it turns out, Aqicn actually stems from a social enterprise project called The World Air Quality Index Project.
What do PurpleAir numbers mean?
Purple means air quality is very unhealthy.
What are the 6 levels of air quality?
These six pollutants are carbon monoxide, lead, nitrogen oxides, ground-level ozone, particle pollution (often referred to as particulate matter), and sulfur oxides.
Which PurpleAir conversion should I use?
If you want the most up-to-date AQI measurements, I’d recommend using Purple Air with AQandU enabled. Once the EPA conversion factor is available on PurpleAir I’d use that instead.
How does a PurpleAir sensor work?
How do PurpleAir sensors work? PurpleAir sensors use PMSX003 laser counters to measure particulate matter in real time, with each laser counter alternating 5-second readings averaged over 120 seconds. Each laser counter uses a fan to draw a sample of air past a laser beam.
What is a PurpleAir?
PurpleAir is a community air monitoring system of PM (10, 2.5, 1.0) air pollution sensors. … PurpleAir sensors use a fan to draw air past a laser, causing reflections from particles in the air. These reflections are used to count particles in six sizes between 0.3 and 10 micrometers in diameter.
Do PurpleAir sensors measure temperature?
The PurpleAir counts the numbers of particles in several size classes and converts them to estimates of mass concentration. In addition to PM2.5 and PM10, the PurpleAir reports the concentration of particles less than 1.0 µm in diameter, called PM1.0. The PurpleAir also measures temperature and relative humidity.