초록 ▼

A multi-functional sensing and measuring system capable of detecting both temperature and humidity is fabricated from a porous metal-oxide ceramic whose dielectric constant varies with temperature and whose electric resistance varies with ambient humidity. The sensing element is connected in series

A multi-functional sensing and measuring system capable of detecting both temperature and humidity is fabricated from a porous metal-oxide ceramic whose dielectric constant varies with temperature and whose electric resistance varies with ambient humidity. The sensing element is connected in series with a resistor and a rectangular pulse voltage is applied across the series combination, and the ambient temperature and humidity are measured simultaneously in terms of (i) the circuit time constant (to measure temperature) of a transient state value and (ii) the steady state value of the voltage across the resistor (to measure humidity).

대표청구항 ▼

A multi-functional sensing system capable of detecting both the temperature and humidity to which it is subjected, comprising: (a) a sensing element comprising a porous dielectric metal oxide ceramic plate the dielectric constant of which varies with temperature and the electric resistance of which

A multi-functional sensing system capable of detecting both the temperature and humidity to which it is subjected, comprising: (a) a sensing element comprising a porous dielectric metal oxide ceramic plate the dielectric constant of which varies with temperature and the electric resistance of which varies with humidity, the major surfaces of said ceramic plate having a pair of electrodes thereon, (b) a resistor element connected in series with said sensing element to one of the electrodes of said pair of electrodes on one of the major surfaces, (c) a rectangular pulse generator means for supplying rectangular pulses across said sensing element and resistor element, (d) means in an electrical circuit connected to the junction of the sensing element and the resistor element for determining temperature by detecting the time difference between the time at which the pulse signal is applied and the time required for the voltage across one of said elements of said series connected elements to reach a reference voltage level, and (e) means in the electrical circuit connected to the junction of the sensing element and the resistor element for detecting humidity by determining the amplitude of the steady state voltage across one of said elements of said series connected elements.