Recessed, surface, or overhead mount
UL 634 · ANSI/BHMA A156.10
Maryland, DC & Northern Virginia
A door sensor tells your building whether a door is open, closed, or about to be used. Some sensors watch door position and report it to your access control or alarm panel. Others spot people and tell an automatic door when to open or stay open. Request-to-exit sensors let staff leave without setting off an alarm. Together, these small devices keep your doors secure, safe, and easy to use. When one fails, you get false alarms, propped doors, or doors that swing shut on people.
Properly aligned sensors report true door status, so your team stops chasing nuisance alarms all night.
Presence and motion sensors stop moving doors from striking people, carts, wheelchairs, strollers, and hospital beds.
Door position switches alert you when a door is forced open or held open too long.
King Locksmith And Doors Inc. installs, repairs, and services commercial door hardware across Maryland, Washington DC, and Northern Virginia. Our technicians service every type of door sensor, from door contacts to automatic door safety sensors. We serve small businesses, government agencies, hospitals, hotels, and enterprises. We test each sensor with your lock, closer, and access control system so the whole opening works as one. You get clear pricing, clean work, and doors you can trust.
The right door sensor depends on the door, the traffic, and the system it reports to. Use this guide to compare sensor types and match each one to how your door is used every day.
A door position switch uses a magnet and a switch to tell your system if a door is closed. Recessed contacts hide inside the frame and door, so they are hard to tamper with. Surface-mount contacts work on doors where drilling is not practical.
Choose the gap size to match your door. Steel doors, wide gaps, and heavy use each call for a different contact. A wrong match leads to false alarms and missed events.
A request-to-exit sensor sits above the door and sees a person walking toward it. It tells the access control panel that someone is leaving, so the door alarm stays quiet. Some models also unlock an electric strike or maglock.
Aim matters. A sensor aimed too wide can unlock the door when people walk past. We set the detection pattern and timing so the door releases only for people leaving, in line with local egress codes.
Automatic doors use two kinds of sensors. Motion sensors open the door when someone approaches. Presence sensors watch the threshold and the swing path, so the door will not close or swing into a person standing there.
ANSI/BHMA A156.10 sets the rules for sensors on power-operated doors, including where they must detect people. Hospitals, hotels, and stores need sensors tuned for carts, strollers, wheelchairs, and heavy foot traffic. Small angle changes make a big difference.
Standard door contacts can be fooled with an outside magnet. A balanced magnetic switch uses a matched set of magnets, so any outside magnet or shift in position triggers an alarm. That makes it the right choice for server rooms, pharmacies, and secure government spaces.
Look for switches listed to UL 634 at the level your site requires. We match each switch to the door type and wire it to report tamper and door status.
Loading dock doors and rolling gates need sensors built for wide gaps, dust, and constant shaking. Heavy-duty overhead door contacts mount on the floor or track and still read correctly when the door shifts in its rails.
Photo-eye safety sensors also stop a closing door when something blocks its path. We check and test both the alarm contacts and the safety sensors, so your dock stays secure without putting workers, drivers, or trucks at risk.
Many buildings weigh hardwired door sensors against battery-powered wireless contacts. Wireless can work in a pinch, but for busy commercial doors, hardwired sensors usually win on the five points below.
Consideration
Hardwired Door Sensors
Wireless Door Contacts
Powered by panel, no batteries to replace
Batteries die and must be swapped regularly
Steady wired signal through walls and steel
Radio signals can drop near metal doors
Recessed, supervised wiring resists tampering
Exposed units are easier to remove or jam
Connects directly to access control and alarms
Often needs extra receivers and added software
Lasts for years with almost no upkeep
Ongoing battery changes and service calls add up
Most door sensor problems start small. A loose magnet or dirty lens can turn into false alarms, unlocked doors, or a safety risk. Watch for these four common warning signs.
We install door position switches, REX sensors, and automatic door sensors on new and existing commercial doors.
We trace faults, replace failed sensors, and fix wiring so your doors report the right status again.
We realign magnets and adjust sensor range, angle, and timing to stop false alarms and missed detections.
We connect door sensors to your access control and alarm panels so every door event gets logged.
We inspect motion and presence sensors against ANSI/BHMA A156.10 so your automatic doors stay safe for everyone.
Scheduled visits catch worn contacts, loose mounts, and dirty sensors before they cause false alarms or downtime.
Tell us about your doors. We will assess every sensor, explain your options, and give you a clear, free estimate.
