PurpleAir Air Quality

Overview

PurpleAir is a company that sells internet-connected pollution sensors that use laser particle counters to provide an accurate and low-cost way to measure smoke, dust, and other particulate air pollution. This global dataset, which we refresh 4x daily (around 0:30, 6:30, 12:30, and 18:30 UTC daily), includes information from outdoor sensors whose owners have chosen to make their readings available to the public. The readings listed in this dataset reflect their values at the time of ingestion, which should be close to the timestamps available in the last_seen_at property.

Attributes

name

The name given to the sensor from the registration form.

string
confidence

Many PurpleAir sensors have multiple counters, which take independent measurements. Confidence (percentage, stored as its decimal equivalent) indicates how closely the measurements align. A confidence of 0.0 (0%) likely indicates an issue with one of the device's counters. A high confidence indicates that the measurements are closely aligned across all the device's instruments.

number
humidity

Relative humidity (percentage, stored as its decimal equivalent) inside of the sensor housing at the time of reading. On average, this is 4% lower than ambient conditions. NULL if not equipped.

number
temperature_raw

Temperature inside of the sensor housing (F) at the time of reading. On average, this is 8F higher than ambient conditions. NULL if not equipped.

integer
temperature

Generally identical to temperature_raw, but NULL when the temperature is outside of the operating range of the device (-40 to 185 degrees Fahrenheit), which would imply a faulty reading.

integer
pressure_raw

Pressure in Millibars at the time of reading. NULL if not equipped

number
pressure

Generally identical to pressure_raw, but NULL when outside a generous range of possible atmospheric pressures (500-1100 millibars).

number
voc_concentration

Volatile organic compound (VOC) concentration (IAQ) in Bosch static iaq units as per BME680 spec sheet at the time of reading. EXPERIMENTAL. NULL if not equipped. At present, very few sensors support

number
ozone_concentration

Ozone concentration (PPB) at the time of reading. NULL if not equipped.

number
pm1_0__mass_concentration

Estimated mass concentration of PM1 (ug/m3) at the time of reading. PM1 are extremely fine particulates with a diameter of fewer than 1 microns.

number
pm2_5__mass_concentration

Estimated mass concentration of PM2.5 (ug/m3) at the time of reading. PM2.5 are fine particulates with a diameter of fewer than 2.5 microns.

number
pm2_5__mass_concentration_24hour

24 hour pseudo (simple running) average for PM2.5 mass concentration.

number
pm_2_5__mass_concentration_1week

1 week pseudo (simple running) average for PM2.5 mass concentration.

number
pm10_0__mass_concentration

Estimated mass concentration of PM10 (ug/m3). PM10 are coarse particulates with a diameter of fewer than 10 microns.

number
pm0_3__count_concentration

Count concentration (particles/100ml) of all particles greater than 0.3 µm diameter.

integer
pm0_5__count_concentration

Count concentration (particles/100ml) of all particles greater than 0.5 µm diameter.

integer
pm1_0__count_concentration

Count concentration (particles/100ml) of all particles greater than 1.0 µm diameter.

integer
pm2_5__count_concentration

Count concentration (particles/100ml) of all particles greater than 2.5 µm diameter.

integer
pm5_0__count_concentration

Count concentration (particles/100ml) of all particles greater than 5.0 µm diameter.

integer
pm10_0__count_concentration

Count concentration (particles/100ml) of all particles greater than 10.0 µm diameter.

integer
last_seen_at

The timestamp of the last time the PurpleAir server received data from the device prior to ingestion.

string