Sensor Start-up Guide

The following steps are what you need to do in order to get your PurpleAir sensor up and running. Your preferred, local or personal, WiFi network will be referred to as local WiFi :wifi: for the remainder of this guide. This local WiFi :wifi: is assumed to have internet access.

Summary Instructions

  1. Connect Your Sensor to WiFi
    To best configure the sensor to your WiFi, we suggest doing so with the sensor, WiFi-enabled device (e.g., cellphone, tablet, laptop), and WiFi-router in the same room.

    1. Power On: Plug in your PurpleAir sensor to an outlet and confirm that it is receiving power.
    2. Connect to Sensor’s Hotspot: Open the network settings of your WiFi-enabled device, and select the Sensor’s Hotspot :hotspot:, PurpleAir-****.1
    3. Connect Sensor to Local WiFi: In the Sensor’s Hotspot Login Page, select the local WiFi :wifi:, then enter the password for that network. Click or tap Save. Switch your Wi-Fi-enabled device back to the local WiFi to regain internet access.
  2. Register Your Sensor for Use on the Map
    Registration may instead be performed before you connect your sensor to WiFi. Use the registration form (https://www.purpleair.com/register) to place a sensor on the PurpleAir Real-time Map.

  3. Sensor Installation
    Mount or place your sensor in the desired location, ensuring to provide a power outlet, and adequate WiFi signal strength.


Detailed Instructions

Connect Your Sensor to WiFi

This section will guide you to configure the WiFi connection on your PurpleAir sensor. The WiFi configuration process is the same for all PurpleAir sensors.

Power On

Plug in your PurpleAir sensor to an outlet and confirm that it is receiving power. For the PA-I, make sure the device itself is glowing, while the PA-II & PA-II-SD, look for the dim, red glow inside the sensor housing. To best configure the sensor to your WiFi, we suggest doing so with the sensor, WiFi-enabled device (e.g., cellphone, tablet, laptop), and WiFi-router in the same room.

Sensor’s Hotspot Login Page
(Pop-up Window)

Connect to Sensor’s Hotspot

Open the network settings of your WiFi-enabled device, and select the Sensor’s Hotspot :hotspot:, PurpleAir-****.1

Once connected to the PurpleAir-**** network,1 load the Sensor’s Hotspot Login Page. Depending on the operating system of your computer or mobile device, you may get a pop-up window or system message to sign in to the network.2 If you receive a message to sign into the network, select it to make the pop-up window appear. The pop-up window will list all available WiFi networks. Select the local WiFi :wifi: and provide its password.

If the pop-up window does not appear, ensure sure you’ve selected the PurpleAir-**** network, open a new tab in a web browser, and enter the default IP address for the sensor in the address bar: http://192.168.4.1/config. See also No Pop-up Window after Connecting to WiFi.

Connect Sensor to Local WiFi

In the Sensor’s Hotspot Login Page, select the local WiFi :wifi:,3 then enter the password for that network. Click or tap Save. Ensure that the WiFi status bar states “WiFi Connected”. Any red or orange indicators on the page are expected to turn green later. For PA-I (indoor), the WiFi status bar will remain grey. For PA-II & PA-II-SD (outdoor) the WiFi status bar will turn green.

Once your PurpleAir sensor has been successfully connected to your local WiFi :wifi:, switch your Wi-Fi-enabled device back to the local WiFi :wifi: to regain internet access. Proceed to register the sensor for use on the PurpleAir map.

Register Your Sensor for Use on the Map

Registration Form

Registration may instead be performed before you connect your sensor to WiFi. Visit https://www.purpleair.com/register to place a new PurpleAir sensor on the Real-time Map, or update registration details on a previously registered sensor.

On the registration form, there are eight, user-defined fields that must be filled to proceed; Device-Id (MAC), Associated Email, Installed,4 Location Name, Visibility,5 Map Location,6 Owner’s Name, and Owner’s Email.7

Select the check-box to affirm your agreement to the terms and conditions. Finally, select the “Register” button to submit your registration.

A registration confirmation email :message: will be sent to the Associated Email and Owner’s Email indicated on the registration form. If the subject line of this email contains “Online”, then the sensor was registered successfully, is online, and reporting to the PurpleAir map.

Once you have successfully registered, you will see your sensor’s marker on the PurpleAir Real-time Map (referred to as Map Marker) within a few minutes. If your sensor is connected to local WiFi :wifi: and has internet access, you should see a colored Map Marker on the map.

Sensor Installation

There are several things that may prove critical to the location chosen to install the PurpleAir sensor. Choose a location to mount or place your sensor that is convenient to reach, has access to a power outlet, and falls within range of the local WiFi :wifi:.

PA-II, PA-II-SD, and PA-II-FLEX Installation

  • If possible, mount the sensor away from vents, local sources of pollution such as barbecues, and any foliage that would increase the likelihood of insects getting inside the laser counters.
  • Install the sensor in the vertical position, with the open end facing toward the ground. The housing is designed to protect the device from the elements while allowing air to flow freely past the two laser counters. This will also help avoid the collection of particles on the lenses in the laser counters.
  • Be sure to mount the sensor high enough off of any surface that would allow rain water to splash up into the underside of the sensor.
  • The power supply should be mounted so that it will not be submerged in water or snow.
  • Use either cable ties or a screw to mount the sensor and power supply, and fashion a "drip loop" to prevent water from running down the wires and into the electronics.
  • PurpleAir outdoor sensors can withstand direct sun without being damaged. Mounting the sensor under the eaves of the roof offers protection from falling objects like branches or hail. We suggest that the mounting location provide such cover.
  • Connect the power supply to a power outlet and tuck the wires away.

PA-I-Indoor Installation

  • The sensor is designed to lay flat on a hard surface like a countertop or desk.
  • Place the sensor in a central location to gather an average reading, or in an area of interest to monitor specific activity. Avoid air vents, humidifiers, and cooking areas.

We do not recommend covering the base of your sensor with any material. This will impact the air flow and ability of the sensor to properly measure particulate matter.

South Coast AQMD Walkthrough Video

The following video is a product of the South Coast Air Quality Management District, as part of their recently published Sensor Educational Toolkit, “Community in Action: A Comprehensive Educational Toolkit on Air Quality Sensors”. The video, Air Sensor Training #3: PurpleAir PA-II Sensor Installation, will walk through many of the steps we covered in this guide to help you get your PurpleAir sensor running. You can read more about the South Coast AQMD Sensor Educational Toolkit by visiting the topic, “The South Coast AQMD Sensor Educational Toolkit.”

Learn More

Learn what to do if you can’t see the sensor’s network, PurpleAir-****.1
Learn what to do if you can’t select or connect to your WiFi network.
Learn what to do if you need to update registration details.
Learn what to consider after installation.

Footnotes

  1. The **** is a 2-4 character code determined by your sensor. Also, it may take up to 10 minutes after the sensor is plugged in for this network to appear. If your sensor network name is AirMonitor_****, you will need to visit http://www.purpleair.com/configure to configure WiFi on your sensor.
  2. If the pop-up window does not appear, then after making sure you’ve selected the PurpleAir-**** network and have waited a few moments,1 open a new tab in a web browser. This should display a page (Sensor’s Hotspot Login Page) onto which you can enter your WiFi details to connect your sensor. Alternatively, open a new tab in a web browser and enter the default IP address for the sensor in the address bar: http://192.168.4.1/config
  3. Once your sensor is successfully configured to the local WiFi :wifi:, it will no longer appear in the list of available networks on your WiFi-enabled device. That is, until your sensor is configured to a local WiFi :wifi:, your sensor will continue to broadcast its own network, PurpleAir-****.1
  4. It’s important to register your device in the correct environment. For example, if a device is registered as “inside” but is in fact installed “outside”, it will report different readings than other outside sensors in the vicinity. Explicitly, an “inside” designation makes the sensor report CF_1 data, while an “outside” designation makes the sensor report ATM data.
  5. Anyone can view public sensors on the PurpleAir Real-time Map. If you register your device as private, only you (and those with whom you share the link provided in the registration email) will be able to see your sensor on the map. To view private sensors on the map, you must use the link provided in the registration confirmation email :message:, or be logged in to the map. If you want to be able to login to the PurpleAir Real-time Map and use the “Show My Sensors” checkbox, then the login email address must be a Google account.
  6. Drag and drop the red marker :red_marker: on the map to select a location for the Map Marker to appear on the PurpleAir map. If no location is set, the Map Marker will be placed near the latitude/longitude “0/0” (which is off the west coast of Africa). If you prefer the Map Marker not be at your direct location, then place it nearby on the nearest intersection or in the middle of your street. This will increase your devices anonymity while maintaining data integrity.
  7. The owner of the sensor usually has physical possession of the sensor. The Owner’s Email may be the same as or different from the Associated Email. The Owner’s Email can be any email address, but must be a Google account if you want to be able to login to the PurpleAir Real-time Map and use the “Show My Sensors” checkbox. Once the Owner’s Email is set, you must contact us if you’d like to change it. In contrast, the Associated Email is the email address used by the buyer to complete the purchase of the sensor and is used to authenticate the registration attempt. A registration confirmation email :message: will be sent to both the associated and owner email addresses.
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