What do purple air numbers mean?

Purple means air quality is very unhealthy.

Why are PurpleAir readings higher?

Broadly put, PurpleAir provides more localized, more current and less accurate readings than AirNow. … PurpleAir readings and those from government sensors like the ones maintained by the Bay Area Air Quality Management District differ in several key ways: speed, accuracy and placement.

What are the six 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.

Are PurpleAir sensors accurate?

For the national data set of sensors collocated with regulatory-grade monitors, results show that PurpleAir sensors, when corrected, accurately report NowCast AQI categories 90% of the time as opposed to uncorrected PurpleAir data, which are accurate only 75% of the time.

What do the AQI colors mean?

AQI colors

For example, the color orange means that conditions are “unhealthy for sensitive groups,” while red means that conditions may be “unhealthy for everyone,” and so on.

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.

Why should I buy a PurpleAir sensor?

Real-time air quality monitoring for people who care about the air. PurpleAir makes sensors that a community of citizen scientists use to collect hyper-local, real-time air quality data and share it on a map that is accessible to everyone.

What does purple air quality mean?

Check the AQI at www.epa.gov/airnow. … Yellow means air quality is moderate. Orange means air quality is unhealthy for sensitive groups — people with heart disease or lung disease such as asthma, children &amp, teens, people who are active outdoors, and older adults. Purple means air quality is very unhealthy.

What is a good air quality number?

What’s a good number for air quality?

How long do purple air 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.

Why are AQI readings so different?

Update frequency: It is possible that different sources update at different times. This can cause different locations to show different data – some current, some outdated. Update time is listed under the air quality reading on the AirVisual app – and can also be found on the US EPA (AirNow) website.

How does purple air measure air quality?

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.

How bad is an AQI of 500?

“An AQI of 500 is exceptionally high. … The higher the AQI value, the greater the level of air pollution and the greater the health concern. “The kind of air quality you are breathing depends on the concentrations of pollutants such as PM 2.5 or PM 10.

What can I do if my AQI is 500?

How bad is 150 air quality?

At 101 to 150, the air is considered unhealthy for sensitive groups: The elderly, children, and people with lung disease are vulnerable to the effects of ozone pollution, and the elderly, children and those with heart and lung disease are at risk from particulate matter.