I have a door between our office and warehouse that has an alarm on it that sounds whenever the door is opened. I am trying to prevent employees from exiting the warehouse but now I’d like office personnel to enter through a warehouse without sounding the alarm. How can I do this?
As your alarm will sound as soon as the magnetic contact is broken (i.e. as soon as the door is opened), you will need a switch that will shunt the alarm when exiting from the office side. The switch will then need to be wired into a timer to keep the alarm from sounding until the door has returned to the closed position. The switch may be controlled by a button, key, a keypad, or even a card/badge reader. Each of these, though, will require the user to perform an extra step before passing through the door. If a seamless passage is what is preferred, a Passive Infrared device (PIR) or a Request to Exit switch (REX) may be used.
The Passive Infrared device is often referred to as a ‘motion detector’. The unit is typically placed above the door and works on the principle of detecting changing infrared radiation patterns. Upon sensing motion — such as someone approaching the door — the PIR will deactivate the alarm.
The Request to Exit switch is placed inside a lock and is triggered by the inner working of the locking device. The mechanical movement of the lock (lever turned, exit bar depressed, etc.) will trigger the REX and deactivate the alarm.
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