Where is the tuning dial?

The tuning dial is already calibrated, it is located inside the top of the unit, underneath the foam, just above the serial number.

1. Remove the rubber face piece
2. Remove the foam
3. Set adjustment screw at default position 11 o’clock
4. Turn right to increase sensitivity
5. Turn left to decrease sensitivity
6. Adjust only 1/16th of a turn and test