False alarm reduction

Many GE motion sensors allow you to select one or two zone detection ( Figure30 ). Each zone is made up of two fields of view, one positive and one negative. With one zone selected, an alarm will be indicated when an intruder moves across one positive and one negative field. With two zones selected, an intruder must cross the positive and negative fields of two zones before an alarm is indicated. We recommend two-zone detection (except when using long-range and curtain lenses) to reduce the chance of false alarms. See the sensor’s installation instructions for details on setting the zone detection.
Figure 30. Zone selection One-zone detectionTwo-zone detection2 beams2 beams2 beams

+-++-- Masking areas on motion sensors

Most motion sensors include masks to modify the coverage pattern to fit specific applications. Coverage curtains should be masked to avoid sources of false alarms such as heaters, air conditioners, and windows. Available masks include:?Plastic masks to cover large areas ( Figure31 on page44)?Adhesive labels used on mirror curtains ( Figure32 on page44)?Undercrawl window masks to improve false alarm immunity in the presence of objects within 5 ft. (1.5 m) and directly under the sensor ( Figure33 on page44)