摘要 |
A combination temperature unit/intruder sensor is described wherein the thermistor used for adjusting the sensitivity of a passive infrared detector in a microprocessor of the unit is also used for the secondary purpose of indicating whether the ambient temperature of a protected zone falls outside a pre-selected temperature range. The detector, in addition to providing signals indicative of an intruder, can provide indications of possible freezing, thawing, or fire conditions. Both the intruder detection and temperature sensing capabilities are provided in a single, inexpensive housing.
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