In this article we will describe how to calibrate sensors on your PocketLab Air and how to interpret your readings.
24 Hour Calibration Procedure
PocketLab Air sensors are calibrated in the factory, but sensor drift can occur during shipment. If you let the PocketLab Air run for 24 hours or more, it will go through a Station Calibration Procedure for all functions. To calibrate, connect PocketLab Air to PocketLab Notebook (info on getting connected to PocketLab Notebook below) and allow the sensor to run for 24 hours. The PocketLab Air can run on battery or plugged into the USB power.
CO2 Field Calibration
Field Calibration: You can calibrate the CO2 function by connect the PocketLab Air to the PocketLab Notebook and exposing it to clean outdoor air for five minutes. Click the graph menu icon on the CO2 graph (three lines) and press the Calibrate option. (Note this calibration method is not yet available on the PocketLab iOS app. However the calibration will save once done in PocketLab Notebook. For more info on PocketLab Notebook, see below).
PM and Ozone Field Calibration
The PocketLab Team is developing other protocols to calibrate the sensor using local monitoring station data from the US Environmental Protection Agency (EPA) and other crowdsourced data. We will update the app and send out more information as we develop those new features.
The Ozone sensor needs to be calibrated to change the offset so that the absolute numbers are more accurate. That calibration procedure will be released soon. In the meantime, relative changes in Ozone are still accurate. You may notice that the instantaneous Ozone readings jump around a lot. This is common in an electrochemical sensor. For Ozone, it is best to look at average data over time. Give the Ozone sensor 10 minutes to settle, then use the 10-minute average graph, rather than the instantaneous readings
Getting Connected to PocketLab Notebook:
PocketLab Notebook is compatible on Google Chrome browsers on Windows 10, Chromebook, Mac, and Android devices. (Note: For iOS devices, use the PocketLab iOS app, downloaded from the Apple App store)
Open a Google Chrome browser
Click "Start Collecting Data" to go to the Trials page
Click "Connect a PocketLab" on the Trials page
A connection window should pop up. (Note: If it doesn't, make sure pop-up blockers are disabled)
Turn on your PocketLab sensor.
The name of your PocketLab should appear in the connection window.
Click on the name of your PocketLab to select it, and then click "Pair"
Your PocketLab should now connect automatically
Once connected, you can Calibrate the CO2 sensor using the CO2 graph menu.