Airtight thermocouple probe
First Claim
1. Elevated temperature measuring apparatus capable of withstanding temperatures in excess of 1650°
- C. for use in oxidizing environments comprising;
a metallic thermocouple probe including first and second electrically conductive leads of dissimilar metals joined at an extreme sensing end and extending from said extreme sensing end to readout means distant therefrom;
insulating means for electrically isolating said first and second electrically conductive leads from one another and for thermally isolating said first and second electrically conductive leads from heat external of said probe;
structural sheath means for receiving said thermocouple probe and said insulating means and for providing mechanical strength to said thermocouple probe and said insulating means, said sheath means having an open end and a closed end, said extreme sensing end of said thermocouple probe located proximate said closed end; and
encapsulating means enveloping said thermocouple probe, said insulating means, and said sheath means adjacent said extreme sensing end for providing a substantially oxygen impermeable barrier to prevent oxygen contained in said oxidizing environment from contacting said thermocouple probe, said insulating means, and said sheath means, and thereby render said thermocouple probe impermeable to the formation of oxides thereon which would render it inoperable.
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Accused Products
Abstract
A metallic thermocouple probe is capable of withstanding temperatures in excess of 1650° C. in oxidizing environments. First and second electrically conductive leads of dissimilar metals are joined at an extreme sensing end and extend to a distant readout device. Metal oxide insulation such as beryllium oxide, magnesium oxide, and aluminum oxide, electrically isolates the conductive leads and thermally isolates them from the environment. The extreme sensing end of the thermocouple probe is encapsulated to render it impermeable to the formation of oxides thereon. This encapsulation includes a protective coating composed of a non-porous ceramic material, preferably a cementation applied disilicide. Additionally, a high temperature structural sheath overlies the insulation adjacent the extreme sensing end and a low temperature sheath overlies the insulation adjacent the first sheath distant from the extreme sensing end. The first and second sheaths abut at a sheath junction and a splice cover overlies the sheath junction and is attached to the first and second sheaths. The first sheath is composed of a refractory metal such as tungsten, tantalum, molybdenum, columbium-zirconium, or their alloys; the second sheath is composed of a material such as stainless steel, INCONEL brand alloys, or glass woven into an overbraid; and the splice cover is composed of a metal such as stainless steel or inconel.
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Citations
21 Claims
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1. Elevated temperature measuring apparatus capable of withstanding temperatures in excess of 1650°
- C. for use in oxidizing environments comprising;
a metallic thermocouple probe including first and second electrically conductive leads of dissimilar metals joined at an extreme sensing end and extending from said extreme sensing end to readout means distant therefrom; insulating means for electrically isolating said first and second electrically conductive leads from one another and for thermally isolating said first and second electrically conductive leads from heat external of said probe; structural sheath means for receiving said thermocouple probe and said insulating means and for providing mechanical strength to said thermocouple probe and said insulating means, said sheath means having an open end and a closed end, said extreme sensing end of said thermocouple probe located proximate said closed end; and encapsulating means enveloping said thermocouple probe, said insulating means, and said sheath means adjacent said extreme sensing end for providing a substantially oxygen impermeable barrier to prevent oxygen contained in said oxidizing environment from contacting said thermocouple probe, said insulating means, and said sheath means, and thereby render said thermocouple probe impermeable to the formation of oxides thereon which would render it inoperable. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
- C. for use in oxidizing environments comprising;
Specification