| 摘要 |
<p>In a first aspect, the present invention is a method, apparatus, and system for detecting a change in position of a door or a window in an alarm system (1) with a singular housing (2) having a magnetometer (10) for monitoring the magnetic field of the earth, and a microprocessor (20) for detecting a change in the position of the singular housing (2) with respect to the magnetic field of the earth. Upon detecting the change, an alarm signal is transmitted to a remote receiving station (6). The device may also be used to determine if an object that it is affixed to has been moved. In a second aspect of the invention, a gravitational sensor (41) is used to monitor the gravitational field of the earth and determine if an associated object has been moved with respect to the gravitational field, thus providing motion detection and signaling an alarm.</p> |
