Autocalibrating dual sensor non-contact temperature measuring device

Claim 1

Apparatus for non-contact measurement of the temperature of a material, comprising: first and second thermally conductive reference bodies each having an operative face facing said material, means for maintaining said first and second reference bodies at different temperatures, including temperature change means mounted in said first reference body operative to change the temperature of said first reference body, first and second heat flow sensors of the same sensitivity carried by said first and second reference bodies, respectively, wherein said first heat flow sensor is reactive to heat flow through the operative face of the first reference body to generate a first heat flow output signal that is proportional to the heat flow rate through the operative face of the first reference body, and wherein said second heat flow sensor is reactive to heat flow through the operative face of the second reference body to generate a second heat flow output signal that is proportional to the heat flow rate through the operative face of the second reference body, first and second temperature sensors carried by said first and second reference bodies, respectively, wherein said first temperature sensor is in thermal communication with and adapted to generate a first temperature output signal that is proportional to the temperature of the first reference body and wherein said second temperature sensor is in thermal communication with and adapted to generate a second temperature output signal that is proportional to the temperature of the second reference body, and means responsive to said first and second heat flow output signals and to said first and second temperature output signals for calculating the temperature of said material.

Claim 12

A method of measuring the temperature of a material comprising the steps of: positioning said material adjacent to first and second thermally conductive reference bodies, so that the distance between the first reference body and said material is the same as the distance between the second reference body and said material, with the material spaced sufficiently close to each reference body so that substantially all of any heat transfer therebetween is conductive--convective heat transfer and only a minor portion is radiant heat transfer, maintaining a temperature difference between the first and second reference bodies, measuring the temperatures of the first and second reference bodies with first and second temperature sensors carried therein, respectively, whereby the first temperature sensor generates a temperature output signal that is proportional to the temperature of the first reference body and the second temperature sensor generates a temperature output that is signal proportional to the temperature of the second reference body, measuring the net rates of the conductive, convective, and radiative heat flow between said material and said first and second thermally conductive reference bodies with first and second heat flow sensors of the same sensitivity carried therein, respectively, wherein said first heat flow sensor is reactive to heat flow through the first reference body to generate a first heat flow output signal that is proportional to the heat flow rate through the first reference body, with said first heat flow sensor situated near the first reference body surface, and wherein said second heat flow sensor is reactive to heat flow through the second reference body to generate a second heat flow output signal that is proportional to the heat flow rate through the second reference body, with said second heat flow sensor situated near the second reference body surface; and calculating the temperature of the material by employing the relationship that the material temperature is equal to the temperature of the first reference body plus the product of E A and B, where E A is the value of the first heat flow output signal where B is equal to the quotient resulting from the division of C by D where C is equal to the temperature of the first reference body minus the temperature of the second reference body and D is equal to E B minus E A , and where E B is the value of the second heat flow output signal.

Claim 13

A method of measuring the temperature of a material comprising the steps of: positioning said material adjacent to first and second thermally conductive reference bodies, so that the distance between the first reference body and said material is the same as the distance between the second reference body and said material, with the material spaced sufficiently close to each reference body so that substantially all of any heat transfer therebetween is conductive--convective heat transfer and only a minor portion is radiant heat transfer, maintaining a temperature difference between the first and second reference bodies, measuring the temperatures of the first and second reference bodies with first and second temperature sensors carried therein, respectively, whereby the first temperature sensor generates a temperature output signal that is proportional to the temperature of the first reference body and the second temperature sensor generates a temperature output that is signal proportional to the temperature of the second reference body, measuring the net rates of the conductive, convective, and radiative heat flow between said material and said first and second thermally conductive reference bodies with first and second heat flow sensors of the same sensitivity carried therein, respectively, wherein said first heat flow sensor is reactive to heat flow through the first reference body to generate a first heat flow output signal that is proportional to the heat flow rate through the first reference body, with said first heat flow sensor situated near the first reference body surface, and wherein said second heat flow sensor is reactive to heat flow through the second reference body to generate a second heat flow output signal that is proportional to the heat flow rate through the second reference body, with said second heat flow sensor situated near the second reference body surface; and calculating the temperature of the material by employing the relationship that the material temperature is equal to the temperature of the first reference body plus the product of E A and B, where E A is the value of the first heat flow output signal where B is equal to the quotient resulting from the division of C by D where C is equal to the temperature of the first reference body minus the temperature of the second reference body and D is equal to E B minus E A , and where E B is the value of the second heat flow output signal.