The first time you use measureQuick, you need to pair your Bluetooth probes to the app. You will also need to re-pair if you reinstall the app, or if you are an Android user who cleared the app data in device settings.
Not sure which probes you need yet? See What Probes do I Need for measureQuick?
The video below demonstrates the pairing process with Fieldpiece probes. The general steps apply to other brands as well, with one exception: Testo probes must each be added individually.
Once your probes are paired, see Proper Wireless Probe Placement for where to mount each one during a test.

