For the last 50 years, virtually all door alarm switches and sensors have used an electromechanical contact that is activated either magnetically or mechanically. Now, new technologies and advanced algorithms surpass the old methods.
The biggest disadvantage to all the old methods is that they rely on a simple sensing element that is either on or off. Noncontact methods such as magnetic sensing have the advantage of long life and potentially wider mounting tolerances, but traditional old magnetic sensing devices utilize a simple on/off device.
A common way to defeat traditional magnetic security switches is to place a thin, strong magnet into the air gap between the actuator and the switch. If the defeat magnet is strong enough to change the traditional security switch from “off” to “on” or vice versa, then the security switch can be defeated.
Our new high-security sensor, Sentinel, does not work the same way. It senses not just the actuator’s magnetic field strength, but also its direction and gradient. The measurements must match the actuator’s magnetic profile just as the tumblers in a lock must match the profile of a key.
A magnetic actuator is just one or more magnets. Sentinel has been developed to measure the actuator more precisely. Because of this, it is almost impossible to magnetically tamper or “fake out” the sensor. One way to understand how it works is to picture the actuator creating a magnetic field that is unique in its strength and direction throughout space. It is almost impossible to recreate this magnetic field without using magnets in the same location as the actuator. The actuator’s unique magnetic field is in effect a magnetic signature or a magnetic key.
Sentinel leverages advances in solid state technology for magnetic sensing and signal processing. The Hall effect sensors used in Sentinel take high-security entry point sensing to a new level.