Touch-free devices feature expensive motion sensors that activate the device automatically, with the wave of a hand or detection of movement. The infrared electronic sensors, particularly in towel dispensers, are typically battery-operated, so the first step in ensuring that they are properly working is making sure good batteries are in place. While sensors can be adjusted for delay times, once they are in place they should not pose operational problems. But making sure they stay in good shape is crucial to their longevity. The sensors themselves must stay free of fingerprints, smudges and other dirt or debris that may inhibit the functioning of the device. Sensors should be wiped with a neutral cleanser at least once daily to prevent blockage of sensors. Damage to the sensor, from vandalism or accidents, can be expensive to remedy, so locate fixtures in places where they are least likely to be in the way or occupants.