How to Obtain Sensor Data

Below is a list of ways to obtain data from PurpleAir sensors. Some require a network connection or a specific type of sensor.

If you’re concerned about reliably collecting data over long periods of time, you’ll also want to examine our Data Collection and Reliability article.

PurpleAir Sensors typically report data at 2-minute intervals. Sections in this article with a star * at the end discuss how to locally retrieve even higher-resolution data.


Obtaining Data if Your Sensor is Registered and Connected to the Internet

Once you’ve connected your sensor to WiFi, it will send any collected data to PurpleAir. You can register your sensor to make reported data available to retrieve.

Please note that SD-capable PurpleAir Sensors do not upload any SD data to our systems. If your sensor experiences an interruption in power or network connection, data for those times will not be available through these methods.

Map

The PurpleAir Map is the primary way many people view their sensor’s data. To add your sensor to the map and set it’s location, you’ll need to register it.

Once registered, a map marker will be created showing your sensor’s readings. Clicking this map marker will display your sensor’s readings over time in a graph.

You can download the data shown in the map graph. However, the map graph will show a limited amount of historical data based on the selected averaging period. A table of times for each averaging period is available here.

API

While the PurpleAir Map provides a graphical way to view sensor data, the PurpleAir API allows for more advanced and programmatic use of reported sensor data. You can use the API to access all reported data from your sensor, as well as publicly reported data from all other sensors.

For further information, our About the PurpleAir API page provides an introduction.

If you’ve chosen to register your sensor privately, you can still access its data from the API using the private read key obtained during registration.


Obtaining Data Without an Internet Connection

SD Data

Not all PurpleAir sensors have a microSD logger. However, the ones that do will write data to an inserted microSD card. SD Data is recorded at the same interval it’s sent to PurpleAir, once every two minutes. The microSD card must then be physically retrieved and plugged into a computer to obtain data.

This data is recorded in CSV format, which can be imported into Excel. The columns of this CSV data are described in our SD Card File Headers article.

Recovering SD Data

Whenever you retrieve SD data, we recommend using the PurpleAir Utility’s SD Data Tool. The SD Data Tool will search for any recoverable data recorded in log files.

Second-by-Second SD Data for Classic-SD Sensors *

For PurpleAir Classic-SD sensors, a hardware modification can be performed to record SD data every second. The modification, as described in the previously linked article, does not work for the PurpleAir Flex or Zen.

PurpleAir Utility * / Serial Data *

PurpleAir Utility *

You can use the PurpleAir Utility to record second-by-second data and display it in a graph. The Utility is an installable program developed by PurpleAir. Using it requires connecting your sensor to a computer.

The Utility records data in a custom format that requires additional processing. This custom format is described in our Understanding PurpleAir Serial Output article.

Serial Data *

The PurpleAir Utility uses USB Serial to access sensor data; any program capable of accessing USB Serial can also access this same data.

Serial data is also available through a hardware connection. If you would like further details on this, send an email to contact@purpleair.com.

Using the Sensor’s Config Page *

If you only need to view the sensor’s readings momentarily, you can do so by accessing the sensor’s config page. This is accessed by either:

The config page has two modes, “Average” and “Live.” You can switch between them by clicking the links near the top of the page.

Average is the default and displays two-minute averaged data (the same data that’s sent to PurpleAir). Live will show measurements from your sensor to the second.

Locally Accessing Data in JSON Format *

If your sensor is connected to WiFi, even if it doesn’t have an internet connection, another device on the same network can query the sensor for its data. This does require some technical ability, with further information available in our View Local Sensor Output Over WiFi (JSON Data) article.

This method also provides access to live readings every second.


Learn More

Power Troubleshooting
SD Card Logging and Troubleshooting
BME Troubleshooting (temperature, humidity, pressure, and VOCs)