page_title: Staircase timer
section_title: Occupancy detectors
hierarchical_section_title: Staircase timer / Occupancy detectors
caption_attribution_description: English: Light switch with PIR-based motion detector
context_page_description: A staircase timer is an electrical switch used to control lighting on a staircase, corridor or lobby. A single action turns on the lights and they remain on for long enough to ascend or descend the stairs. The lights then turn themselves off automatically.
context_section_description: PIR sensors may be used to control lighting in such areas. They avoid the need to press a push-button but otherwise operate as for electronic timers. As PIR sensors are not perfectly reliable a timer is needed to avoid the lights flashing off and on as the occupier moves out of detector range. The timer interval is short though compared to a push-button timer; it times the interval between sightings of the occupier, not the time of occupancy.
  Such sensors are also used for restrooms. Owing to the variability of occupancy time in a restroom, a simple fixed timer was unworkable. This ability to cope with variably occupancy times is also useful when stairwells, lift lobbies and corridors must grant disabled access as they no longer discriminate in favour of an assumed transit time for an able-bodied person.
caption: Combined PIR sensor and lightswitch
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