Fast response temperature sensor and method of making

Claim 2

In combination with temperature sensing means having a body of electrical resistance material of a resistivity which varies with change in temperature, lead means electrically connected to the body for connecting the body in an electrical circuit, means encapsulating the body and portions of the lead means for shielding the body from an environment in a zone whose temperature is to be monitored and for locating the lead means relative to the body, and means having relatively greater thermal conductivity that the encapsulating means secured in heat-transfer relation to the body of resistance material so that a portion of the thermally-conducting means extends outside the encapsulating means for receiving and conducting heat to the body from the temperature zone to be monitored, mounting means for the temperature sensing means comprising a plurality of housing sections of a material of relatively lower thermal conductivity than said thermally conducting means, said housing section being secured together to hold the temperature sensing means therebetween with said extending portion of the thermally conducting means exposed to receive and conduct heat from the temperature zone to be monitored, said housing sections having extensions thereof disposed in spaced surrounding relation to the exposed portion of the thermally conducting means to shield said exposed portion from physical blows while permitting fluid flow around said exposed portion in the zone to be monitored.

Claim 3

Temperature sensing apparatus as set forth in claim 1 wherein said housing sections are formed of organic material of relatively low thermal conductivity and have interfitting portions locating the sections relative to each other to hold the temperature sensing means therebetween, and a metal bushing having mounting means thereon is fitted over the housing sections at one end thereof to hold the sections together with said housing extensions and the extending portion of the thermally-conducting means extending from one end of from one end of the bushing.

Claim 4

Temperature sensing apparatus as set forth in claim 2 wherein said housing extensions engage the extending portion of the thermally-conducting means at the distal end thereof for limiting vibration of the thermally-conducting means during use.

Claim 5

Temperature sensing apparatus as set forth in claim 2 wherein said encapsulating means include first means encapsulating the body of resistance material and adjacent first ends of said lead means and second means spaced from the first means encapulating additional portions of the lead means intermediate said first ends and opposite ends of the lead means, said lead means having first portions of limited cross-sectional size between said first and second encapsulating means limiting heat transfer from the body of resistance material through the lead means, said lead means being of relatively greater cross-sectional size between said additional portions of the lead means and the opposite ends of the lead means for providing relatively greater strength in electrically connecting the body of resistance material in an electrical circuit.

Claim 6

Temperature sensing apparatus as set forth in claim 4 wherein said housing sections engage said second encapsulating means for holding the temperature sensing means between the sections with said lead means portions of said relatively greater cross-sectional size extending from the opposite end of the metal bushing to provide strain relief between the electrical connection of said lead means to the body of resistance material and the electrical connection of said lead means in an electrical circuit.

Claim 7

Temperature sensing means as set forth in claim 5 wherein said housing extensions engage the extending portions of the thermally-conducting means at the distal end thereof for supporting said extending portion of the thermal-conducting means, the first encapsulating means, and said first portions of the lead means to be exposed to substantially the same temperature conditions in a temperature zone to be monitored while limiting vibration thereof during use.

Claim 8

A fast response temperature sensing apparatus particularly adapted for use in a rarefied media comprising a generally planar body of crystalline semiconducting material having a pair of broad flat opposite sides and having a selected dopant concentration therein providing the material with a precisely predetermined positive temperature coefficient of resistivity in a selected temperature range, a pair of ohmic contact means secured to the respective opposite sides of the body to form a spreading resistance type of resistor element having precisely predetermined resistance properties, metal lead frame means having a pair of leads connected to the respective contact means for electrically connecting the resistor element in an electrical circuit, dielectric means encapsulating the resistor element and portions of the leads for shielding the element from an environment in a zone whose temperature is to be monitored and for locating the leads relative to the element, said lead frame means having vane means of relatively greater thermal conductivity than the encapsulating means secured in heat-transfer relation to the resistor element to extend outside the encapsulating means for receiving and rapidly conducting heat to the resistor element from the temperature zone to be monitored, said spreading resistor element having a heat capacity which is small relative to the heat capacity of the vane means so that change in temperature of the element occurs substantially simultaneously with change in temperature of the vane means, a plurality of housing sections of a material of relatively lower thermal conductivity than said vane means, said housing sections being secured together to engage and hold said encapsulating means therebetween for exposing the vane means to promptly receive and conduct heat from a rarefied or other fluid in the temperature zone to be monitored, said housing sections having extensions thereof disposed in spaced surrounding relation to the vane means for protecting the vane means from physical blows while permitting flow of said fluid around the vane means.

Claim 9

A fast response temperature sensing apparatus particularly adapted for use in a rarefied media comprising a generally planar body of crystalline semiconducting material having a pair of broad flat opposite sides and having a selected dopant concentration therein providing the material with a precisely predetermined positive temperature coefficient of resistivity in a selected temperature range, a pair of ohmic contact means secured to the respective opposite sides of the body to form a spreading resistance type of resistor element having precisely predetermined resistance properties, metal lead frame means having a pair of leads connected to the respective contact means for electrically connecting the resistor element in an electrical circuit, dielectric means encapsulating the resistor element and portions of the leads for shielding the element from an environment in a zone whose temperature is to be monitored and for locating the leads relative to the element, said lead frame means having vane means of relatively greater thermal conductivity than the encapsulating means secured in heat-transfer relation to the resistor element to extend outside the encapsulating means for receiving and rapidly conducting heat to the resistor element from the temperature zone to be monitored, said spreading resistor element having a heat capacity which is small relative to the heat capacity of the vane means so that change in temperature of the element occurs substantially simultaneously with change in temperature of the vane means, a plurality of housing sections of a material of relatively lower thermal conductivity than said vane means, said housing sections being secured together to engage and hold said encapsulating means therebetween for exposing the vane means to promptly receive and conduct heat from a rarefied or other fluid in the temperature zone to be monitored, said housing sections having extensions thereof disposed in spaced surrounding relation to the vane means for protecting the vane means from physical blows while permitting flow of said fluid around the vane means.

Claim 10

A fast response temperature sensing apparatus as set forth in claim 7 wherein said encapsulating means include first means encapsulating the resistor element and adjacent, first ends of the leads and second means spaced from the first means encapsulating additional portions of the leads intermediate said first lead ends and opposite ends of the leads, said leads having first portions of limited cross-sectional size between the first and second encapsulating means limiting heat transfer from the resistor element through the leads, said leads having a relatively greater cross-sectional size between said additional lead portions and the opposite lead ends providing relatively greater lead strength in electrically connecting the resistor element in an electrical circuit.

Claim 11

A fast response temperature sensing apparatus as set forth in claim 8 wherein said housing sections engage said second encapsulating means to provide strain relief between electrical connection of the leads to the resistor element and electrical connection of the leads in an electrical circuit.

Claim 12

A fast response temperature sensing apparatus as set forth in claim 9 having a metal bushing having mounting means thereon for use in mounting the apparatus, said bushing being fitted over the housing sections at one end thereof to hold the sections together with said housing sections and said vane means extending from one end of the bushing to be disposed in the temperature zone to be monitored, said bushing being located on said housing sections so that said opposite lead ends extend from the opposite end of the bushing to be connected in said electrical circuit.

Claim 13

A temperature sensing device comprising a body of electrical resistance material having a resistivity which varies with change in temperature, lead means electrically connected to the body for connecting the body in an electrical circuit, means encapsulating the body and portions of the lead means for shielding the body from an environment in a zone whose temperature is to be monitored and for locating the lead means relative to the body, and thermally-conducting means of relatively greater thermal conductivity than the encapsulating means secured in heat-transfer relation to the body of resistance material so that a portion of the thermally conducting means extends outside the encapsulating means for receiving and conducting heat to the body from the temperature zone to be monitored, said encapsulating means including a first portion encapsulating the body of resistance material and the first ends of the lead means adjacent to the body of resistance material, and a separate second portion spaced from the first portion encapsulating additional portions of the lead means between said first ends and the opposite ends of the lead means, said lead means having first portions of limited cross-sectional size located to extend between the first and second encapsulating portions for limiting heat-transfer from the body through the lead means while permitting the device to be mounted with said first and second encapsulating portions held separated to limit stress on said first lead portions, said lead means being of relatively greater cross-sectional size between said additional portions of the lead means and said opposite ends of the lead means providing relatively greater strength in electrically connecting the body of resistance material in an electrical circuit.

Claim 14

A temperature sensing device comprising a body of electrical resistance material having a resistivity which varies with change in temperature, lead means electrically connected to the body for connecting the body in an electrical circuit, means encapsulating the body and portions of the lead means for shielding the body from an environment in a zone whose temperature is to be monitored and for locating the lead means relative to the body, and thermally-conducting means of relatively greater thermal conductivity than the encapsulating means secured in heat-transfer relation to the body of resistance material so that a portion of the thermally conducting means extends outside the encapsulating means for receiving and conducting heat to the body from the temperature zone to be monitored, said encapsulating means including a first portion encapsulating the body of resistance material and the first ends of the lead means adjacent to the body of resistance material, and a separate second portion spaced from the first portion encapsulating additional portions of the lead means between said first ends and the opposite ends of the lead means, said lead means having first portions of limited cross-sectional size located to extend between the first and second encapsulating portions for limiting heat-transfer from the body through the lead means while permitting the device to be mounted with said first and second encapsulating portions held separated to limit stress on said first lead portions, said lead means being of relatively greater cross-sectional size between said additional portions of the lead means and said opposite ends of the lead means providing relatively greater strength in electrically connecting the body of resistance material in an electrical circuit.