GB1399031A - Device for instantaneously measuring the temperature of a body - Google Patents

Abstract

1399031 Measuring temperature electrically M POSSATI [trading as APPARECCHI ELETTRONICI MARPOSS] 14 April 1972 [14 April 1971] 17471/72 Heading G1N [Also in Division G4] An electrical temperature sensing device for substantially instantaneously measuring the temperature of a workpiece 11 comprises a containing member in the form of a tracer point 12 embedded in which is a temperature-sensing element 13 and a temperature measuring circuit which calculates the workpiece temperature from the signal at inlet 21 fed from the element 13; the signal being a function T(t) say where T(t)=(1 + K 1 e/<SP>-t/a</SP>1 + ... + K n e <SP>-t/a</SP>n). X in which X is workpiece temperature; a 1 ...a n are functions of the thermal resistances R 1 ... R n of the elements 12a ... 12n of the tracer point and K 1 ... K n are functions of the thermal capacities C 1 ... C n of said elements; block 22 is a derivative network for function T(t) and also multiplies the derivative by the function a 1 the resultant being summed with T(t) at block 23 to yield T 1 (t) = T(t) + a 1 dT(t)/dt the function T 1 (t) being similarly processed to produce T 2 (t) and so on to produce function T n (t) at outlet 24 whereby T n (t) = X, the workpiece temperature. An alternative embodiment Fig. 3 (not shown) of the circuit is for the general case where the low governing the variation of workpiece temperature X t is X t = H o .T t +H 1 dT(t)/dt+...+H n (dnT(t)/dtn) 1399070 Liquid level indication TOYOTA JIDOSHA KOGYO KK 19 Dec 1973 [11 Aug 1973] 59319/73 Heading G1H In a liquid level detecting and indicating device for indicating the quantity of oil in an engine an indicating lamp 14, in the vicinity of the drivers seat, is connected to a battery 17 through an ignition switch 15 and an N.P.N. transistor 16 the base of which is connected to a point between a bias resistor 19 and a level shift diode 20 and operation of switch 15 applies a voltage to transistor 16 to energize the lamp 14, if the oil is not at the predetermined level but not if the oil is at the predetermined level. A by-pass circuit comprising a set of encapsulated electrical contacts 22 in an oil level detector 21 and a second set of encapsulated contacts 24 in a level stabilization detector 23, will be operated by closing contacts 22 if the level is correct but the contacts 22 will remain open if the level is incorrect. In an alternative arrangement, Fig. 9 (not shown), two stabilization detectors, are provided. In a further arrangement, Fig. 6 (not shown), a PTC thermistor (posistor) is used.