PA-II Dual Laser Air Quality Sensor

Thank you for purchasing or hosting a PurpleAir device.

In the box

1) Dual laser counter + BME280 to provide particulate, temperature, humidity and pressure.

2) Marine heat shrink pre-joined USB micro.
3) 5V 2A USB Outdoor Power Supply.
4) 33 feet of cable.
5) Mounting screws or Zip Ties.

Step 1: Register your sensor

The registration form provides us with the information we need to display your sensor on the PurpleAir Map. Register by completing the form on the right of this page.

Step 2: Connect your PurpleAir sensor to your WiFi network:

After connecting the PurpleAir sensor's power supply to a power socket,

  1. Connect a phone, tablet or pc to a WiFi network called "AirMonitor_xxxx"*.
  2. Once connected, open a web browser and enter "" in the address box to open the sensor's status page. If this fails, check step 1 and try again.
  3. Press the WiFi Settings link at the top left, then select your home's WiFi network, enter your WiFi password and press save. **
  • The sensor will then start uploading data to PurpleAir and the map marker should light up.
  • After the sensor's successful connection to WiFi, the AirMonitor_xxxx network will no longer be available.
  • * When the PurpleAir sensor is powered and cannot connect to WiFi, it creates it’s own WiFi network with a name similar to AirMonitor_xxxx where the xxxx is specific to your sensor.
  • ** PurpleAir sensors will only work on 2.4GHz WiFi networks. They will also not work on networks where you need to login on a web page to access the internet. In this last case, your network administrator will need to do one of the following:
    1. Enable the MAC address of the sensor to access the internet without the web login. OR
    2. Setup a separate SSID using WPA2-PSK with it's own password for use by the sensor.

Step 3: Install the sensor.

Before installing your PurpleAir sensor outdoors, you should first consider the following:
  • The housing is designed to protect the device from the elements while allowing the air to flow freely past the two sensors.
  • The power supply is water proof (resin filled) but should be mounted so that it will not get submersed in water or covered by snow.
  • A special technique called a "drip loop" should be used with any wires to prevent rain water from running directly down wires into the device, power supply or power outlet.
  • It is best to mount the sensor in a shady spot like under the eve of the roof on the side of the house that does not get direct sun throughout the day.
  • It is best to mount it away from vents or other local sources of pollution like BBQ's. Note: This may not always be possible, but will produce better data!
  • You need a power outlet and the sensor's power lead is 33 feet long.
Once you know where the device is going, you need to attach the sensor.
  • Using either a cable tie or screw (or any other method you choose!) attach the aluminum bracket to the chosen location.
  • Connect the power supply to the outlet and mount it away from the ground, water or where it would be covered in snow.
  • Route and tuck the wires away.
 Using a single screw and attaching under the eve of the roof.Mounted under eve of roof Using cable ties and attaching to a railing or similar place.Mounted on railing with cable ties