TEMPERATURE SENSOR AND TEMPERATURE DETECTOR USING THE SAME

摘要

PURPOSE:To detect temperature by providing electrodes on mutually opposite surfaces of a pyroelectric body made of a rhombohedral system titanic acid lead zirconate ceramic composite body which has a specific coefficient of pyroelectricity. CONSTITUTION:The pyroelectric body 1 is the rhombohedral system titanic acid lead zirconate ferroelectric ceramic composite body which has the maximal inflection point of the coefficient of pyroelectricity between -50 and +130 deg.C and an electrode 2 and a lead wire 3 are provided on both surfaces and covered with a well-heat- conductive insulator film 4. This temperature sensor generates a pyroelectric current as the temperature rises. Current-voltage conversion 6 and voltage amplification 10 are performed and the resulting voltage is applied to the inverted input terminal of a comparator 7. The comparator 7 inputs a reference voltage V0 from a reference voltage setting means 8 and generates its output when the output of an amplifier 10 reaches V0 to operate a driving circuit 9, thereby generating a warning. The output of a current voltage converter 6 depends upon the coefficient of pyroelectricity and a temperature gradient, but fluctuations of 2- - 3-fold temperature gradients can be removed by proper setting and the maximal inflection point temperature of the coefficient of pyroelectricity is accurately detected.