| 摘要 |
<p>A detection system capable of distinguishing between types of intruder passing into a protected area. The detection system includes means (Tx1-5) for transmitting a plurality of electromagnetic (infrared) beams, the beams being arranged such that an intruder passing into the protected area causes a break in at least one of the beams. The detection system includes means (Rx1-5) for receiving the electromagnetic (infrared) beams and for detecting breaks in the beams. The detection system also includes processing means (57) such as a microprocessor for receiving data associated with breaks in the beams. The processing means may initiate an alarm condition whenever the data associated with the breaks in the beams matches a predetermined beam signature i.e. a predetermined number or sequence of breaks in the beams. The microprocessor may be adapted to store a library of beam signatures for the purpose of identifying certain types of intruders. A swimming pool alarm incorporating the above detection system is also disclosed.</p> |
