Every sensor and Cloud Connector carries a QR code. Scanning it is the quickest way to tell which device you are holding when a shelf holds four identical boxes.
Scanning from the home screen
Tap the round QR button in the bottom right corner. The camera opens, so allow camera access if your phone asks for it. Point the camera at the code on the device and hold steady until it reads.
The sensor opens with its signal strength, its placement and the rules watching it. Tap Data at the bottom for its readings.
If the code belongs to a device that is not in this project, you get No sensor found. Check which project you are signed in to, then scan again.