PurpleAir Classic Air Quality Monitor
PurpleAir Classic Air Quality Monitor
PurpleAir Classic Air Quality Monitor
PurpleAir Classic Air Quality Monitor
PurpleAir Classic Air Quality Monitor
PurpleAir Classic Air Quality Monitor
PurpleAir Classic Air Quality Monitor

PurpleAir Classic Air Quality Monitor

Regular price
Sale price

The PurpleAir Classic air quality monitor is the original and popular PurpleAir sensor. It measures real-time PM2.5 concentrations for residential, commercial, or industrial use and can be installed indoors or outdoors. Built-in WiFi enables the air quality measurement device to transmit data to the real-time PurpleAir Map, which is stored and made available to any smart device. 

The PA-II is available in two editions. The SD edition includes an onboard SD logger to record and store data without a WiFi connection.

Please note: This sensor does not come with a power adaptor. Find a suitable OUTDOOR-rated adaptor here or use your own USB power source (any 5V, 1.2 to 2.4 amp adaptor will work).

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  • Classic PurpleAir PA-II particulate sensor
  • Dual Laser Particle Counters (PMS-5003)
  • Pressure, Temperature & Humidity Sensor (BME280)
  • WiFi connectivity with data stored in the cloud
Classic PurpleAir dual laser particulate sensor
Dimensions 3.5 in x 3.5 in x 5 in
(85 mm x 85 mm x 125 mm)
Color White
Power requirements 5V USB Micro, 0.18A continuous, 600mA peak
Intended Use Outdoor and indoor use
WiFi Yes
Expansion Port No
Internal Storage No
Warranty One (1) year limited warranty
Laser Particle Counters

Class 1 Laser. A Class 1 laser is safe under all conditions of normal use.

Manufacturer Plantower

This device contains two particle detectors to provide redundancy and help determine sensor health.

Type PMS-5003 (2)
Range of measurement 0.3, 0.5, 1.0, 2.5, 5.0, & 10 μm
Counting efficiency 50% at 0.3μm & 98% at ≥0.5μm
Effective range
(PM2.5 standard)*
0 to 500 μg/m³
Maximum range (PM2.5 standard)* ≥1000 μg/m³
Maximum consistency error (PM2.5 standard) ±10% at 100 to 500μg/m³ & ±10μg/m³ at 0 to 100μg/m³
Standard Volume 0.1 liter
Single response time ≤1 second
Total response time ≤10 seconds
Pressure, Temperature, & Humidity Sensor
Manufacturer BOSCH
Model Number BME280
Temperature range -40°F to 185°F (-40°C to 85°C)
Pressure range 300 to 1100 hPa
Humidity Response time (τ63%): 1s
Accuracy tolerance: ±3% RH
Hysteresis: ≤2% RH

Contains Transmitter Module FCC ID: 2AC7Z-ESPWROOM02D

Wireless Networks 802.11b/g/n @ 2.4GHz
(WPA2 pre-shared key or open networks)
Certificates FCC/CE/TELEC/SRRC
Tx Power 802.11 b: +20 dBm
802.11 g: +17 dBm
802.11 n: +14 dBm
Rx Sensitivity 802.11 b: -91 dbm (11 Mbps)
802.11 g: -75 dbm (54 Mbps)
802.11 n: -72 dbm (MCS7)
Antenna Type 2 dBi on-board PCB antenna

FCC Compliance Statement (Part 15.19)

This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions:

  1. This device may not cause harmful interference, and
  2. This device must accept any interference received, including interference that may cause undesired operation.

Warning (Part 15.21)

Changes or modifications not expressly approved by the party responsible for compliance could void the user’s authority to operate the equipment.

FCC Interference Statement (Part 15.105 (b))

This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one of the following measures:

  • Reorient or relocate the receiving antenna.
  • Increase the separation between the equipment and receiver.
  • Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
  • Consult the dealer or an experienced radio/TV technician for help.

To comply with FCC/IC RF exposure limits for general population / uncontrolled exposure, the antenna(s) used for this transmitter must be installed to provide a separation distance of at least 20 cm from all persons and must not be co-located or operating in conjunction with any other antenna or transmitter.

Customer Reviews

Based on 25 reviews
Morgan Seeley
Providing another data point

As wildfire smoke and other pollutants in our air increase, I was interested in helping out in any way possible. I noticed that there were no monitors reporting in my area. This was my solution. It seems a bit pricey, and the setup instructions are almost totally useless, but now when I go to the air quality maps online, my personal station shows up. I guess there's an app that I could install to access the local data more directly, but that's way over my head.

Easy to install, convenient web chart of data, needs simpler history download

The PurpleAir Classic device was easy to install, and offers convenient web charting of data. Downloading historical data could be made much simpler. A “mobile unit” option would also be helpful (useful for periodic monitoring of several sites).

Bob Steventon
It works.

It is nice to see a dot that represents our location on the purple air map. We can see when wildfire smoke (in the summer) and industrial emissions (any time) are an issue.

George B.
great to have micro local details

To me the temperature, humidity, and air pressure numbers are extremely useful, in addition to the air quality data. I don't have close neighbors, but I can compare sensor data from 5 or so miles away to get a good overview of my area.

Edward Mitchell
Fast ship, easy install, works well

We are in fire season in our arid west location. Keeping track of AQI is helpful in knowing when we can keep our windows open, and when it is best not too. Just looking at smoke haze or guessing from the smell turns out not to be an accurate metric - better to track the actual AQI. Shipment from PurpleAir was very quick, installation was easy and the unit works perfectly.