When you fasten the Ava bracelet around your wrist, the device will give a short vibration signal and the LED light on top of the bracelet gives a solid green signal (Ava bracelet 1.2: a solid white signal).
Also, if you want to double-check, there is a sensor light on the underside of the sensor pod that should switch on upon contact with your skin. This light should stay on as long as the bracelet is in contact with your skin and should still be on when you wake up in the morning.
Ava bracelet 2.0 and above
It’s possible that your bracelet may not vibrate immediately upon coming into contact with your wrist. Please note that it can take up to 5 minutes until your bracelet vibrates to indicate that it has started recording data.
Ava bracelet 1.2
If the underside green sensor light does not turn on upon coming into with your wrist, try sandwiching the sensor pod between two fingers, taking care to touch the black rectangular sensor to see if that will prompt the green light to turn on.