Introduction
Welcome to PurpleAir! By purchasing a sensor, you have joined a worldwide network of people striving to better understand their air. You can now contribute to that network by setting up your device. Doing so will empower the community with high-quality, real-time data.
Users who are concerned about privacy have the option to mark their devices as private during registration.
This article is meant to serve as a starting point for your journey with PurpleAir. In it, you’ll find information regarding:
- Some basics of air quality
- How to set up your sensor
- How to view your sensor on the map
- How to download raw sensor data
Monitoring Air Quality
PurpleAir sensors measure particulate matter (PM). The United States Environmental Protection Agency (EPA) defines PM as “a mixture of solid particles and liquid droplets found in the air. Some particles, such as dust, dirt, soot, or smoke, are large or dark enough to be seen with the naked eye. Others are so small they can only be detected using an electron microscope" (Particulate Matter (PM) Basics | US EPA).
When discussing air quality, you may hear the term “PM2.5,” which refers to particles that are 2.5 microns (micrometers) in diameter and smaller. For comparison, a human hair is generally 50 to 70 microns in diameter (see image below).
People concerned about air quality related health issues often discuss PM2.5, as it has been found to be harmful to human health. The EPA discusses the damaging effects of PM2.5 here: Health and Environmental Effects of Particulate Matter (PM) | US EPA
If you want to learn more about PM, the South Coast Air Quality Management District in California has created an educational toolkit that can be found here: The South Coast AQMD Sensor Educational Toolkit
Where Can I See My Sensor?
The PurpleAir map is where your device will show up once set up, and is also where all other public sensors can be viewed. You can access your sensor’s data on the map by selecting its location marker. This will cause a data graph to appear. See example to the right:
Various types of data from your sensor can be viewed on the map. This and other map settings can be changed in the Configuration Menu
Air Quality Indexes
Generally, we have observed that PurpleAir community members prefer to view the data from their sensors in the form of an air quality index (AQI). An AQI is a measure of health impact that corresponds with air quality data. A majority of AQIs are created and supported by governmental organizations.
For example, the default option on the PurpleAir map is the “US EPA PM2.5 AQI,” which is an air quality index created by the US EPA. The scale for that index can be viewed below:
Read our article on which data layer to choose for more information.
Setting Up Your Sensor
To be able to see your sensor on the map, you’ll first need to connect it to WiFi and register it.
Connecting to WiFi
To connect your sensor to WiFi, follow the steps below:
- Connect your sensor to power. Once plugged in, it will power on automatically.
- On a WiFi-enabled device (such as a computer or smartphone), search for and connect to the PurpleAir-**** network.
- Once connected, a page should appear after a few seconds. On that page, select your WiFi network and input the password.
- Press “Save.”
If you’re having trouble, or need more detailed information on the connection process, check out the WiFi configuration section of our Sensor WiFi and Registration Guide.
We recommend doing these steps before the device is installed in its final location.
Register it on the Map
To register your device, visit www.purpleair.com/register and fill out the provided form. You will need to provide the email used to purchase your sensor in the “Associated Email” field.
Additionally, you choose where your sensor appears on the map. You do this by moving the map marker 
available in the map box to the location you want, or by inputting a set of coordinates. Please note that you can zoom in and out to make the chosen location more accurate.
If you would like further details or encounter problems during this process, go to the Registration section of our Sensor WiFi and Registration Guide.
View Your Data Online
Now that your sensor has been configured to WiFi and registered, you can view it on the PurpleAir map.
After device registration, you should receive a confirmation email. This email contains a custom link that will take you directly to your sensor on the map. Alternatively, you can simply navigate to the location you set during registration.
Sensors can be registered as public or private. Private sensors can only be viewed by logging into the PurpleAir map or using a custom link.
Installing Your Sensor
A majority of PurpleAir sensors are designed to be mounted (excluding the PurpleAir Touch). When mounting a sensor, there are a couple of things we think are important. First, you should install your sensor where you want to monitor the air. The most important thing your device can do is inform you on air quality in areas you think need monitoring. However, we also think it is important for your sensor to be fairly easily accessible. If maintenance is ever needed, it will be beneficial to have it in a location that is conveniently accessed.
More information is available in our sensor installation guide: Sensor Installation
Accessing / Downloading PurpleAir Data 
Data from PurpleAir sensors can be accessed in a number of ways:
- Most commonly, community members access data by viewing their sensor’s graph on the PurpleAir map.
- These graphs can also be downloaded directly as an image or in CSV format.
- For advanced usage of sensor data, including yours or thousands of others, you can use the PurpleAir API.
Our How to Obtain Sensor Data article contains further details, and ways to access data locally or second-by-second.
Troubleshooting and Support
Your first resource for troubleshooting is the PurpleAir Community site. Here, you can find many troubleshooting articles written by PurpleAir staff, and common questions answered by other community members. If you don’t see your question, feel free to ask! It is sure to help you and others who may be experiencing the same issue.
If all else fails, please get in touch with us by sending an email to contact@purpleair.com.
We want to leave off by once again welcoming you to the PurpleAir community. We also want to highlight that these forums are meant for much more than just troubleshooting. If you have something else to share, such as an interesting project or a suggestion for PurpleAir, we welcome those posts here.
