Final answer:
Garage door sensors must be installed no higher than 6 inches above the garage floor to ensure safety by detecting small objects that could be obstructed by the door.
Step-by-step explanation:
The standard regulation for mounting a garage door sensor stipulates that the device shall not be mounted higher than 6 inches above the garage floor. This height is a safety measure designed to ensure that the sensor will detect small objects, such as a child or a small animal, to prevent the door from closing on them. Proper installation and placement of the garage door sensor is crucial for the safety and functionality of the garage door system.