PASSIVE INFRARED DETECTOR THAT SPECTRALLY EVALUATES THE HEAT RADIATION EMITTED BY AN OBJECT

摘要

The sensor (3) breaks down the incident infrared radiation into four spectral channels for which corresp. wavelength-dependent electrical signals (A1-A4) are produced. These signals are filtered (4) and their amplitudes are evaluated (5) for presentation to a logic unit (6). The spectral fundamental patterns of emission characteristics of a variety of infrared sources are stored in the memory (7). The mean voltage amplitude over the entire wavelength range is used as a basis for comparison. If correspondence to the stored patterns lies within allowed limits, the source is identified and an alarm given.