초록 ▼

In an improved intrusion detection device system of the dual-sensor type, wherein one sensor is a PIR sensor and the other is a microwave sensor, the improvement comprises counting the detection of intrusion separately by the microwave sensor and by the passive infrared sensor. Thereafter, the count

In an improved intrusion detection device system of the dual-sensor type, wherein one sensor is a PIR sensor and the other is a microwave sensor, the improvement comprises counting the detection of intrusion separately by the microwave sensor and by the passive infrared sensor. Thereafter, the counts by the two separate detectors are compared and an indication is given if the number exceeds a certain user selectable threshold, to indicate fault in one of the two sensor subsystems.

대표청구항 ▼

In an intrusion detection apparatus of the type having dual sensing means, a first sensing means for generating a first output signal in response to the detection of an intruder, a second sensing means for generating a second output signal in response to the detection of an intruder, and logic means

In an intrusion detection apparatus of the type having dual sensing means, a first sensing means for generating a first output signal in response to the detection of an intruder, a second sensing means for generating a second output signal in response to the detection of an intruder, and logic means for receiving said first and said second output signals and for generating an alarm in response thereto, wherein the improvement comprising: first means for storing the number of first output signals received from said first sensing means; second means for storing the number of second output signals received from said second sensing means; and logic means for comparing the number of first output signals from said first storing means and the number of second output signals from said second storing means and for generating an output signal indicative of fault in said apparatus, in response to said comparison.