Abstract: A self-diagnostic thermocouple (10) having a first (12), a second (14) and a reference (16) thermoelement enclosed in a sheath (20) filled with an insulator (18) separating the thermoelectric elements from each other and the sheath. The three thermoelements (12,14,16) are joined at a common location to form three separate thermocouple junctions (22) having three distinct electrical outputs as a function of temperature. The reference thermoelement (16) is made from a pure metal or alloy which has stable thermoelectric characteristics. Deterioration of the electrical output of the self-diagnostic thermocouple (10) is capable of being detected by a programed microprocessor (100).

Abstract: A method for making mineral insulated cables in which a mineral powder is purified to remove magnetic particles. The purified mineral powder and at least one wire are fed into a seam-welded metal sheath as it is being formed to produce the mineral insulated cable. The mineral insulated cable may then be drawn and annealed to reduce the diameter of the cable to the desired size.

Abstract: An oxidation-resistant alloy for use in a high-temperature or thermal cycling environment. The alloy comprises a nickel-based matrix having a solid solution of 19-23% chromium and 3-6% aluminum. A self-healing, thermodynamically stable oxide layer is formed upon a surface of the alloy which is exposed to an oxidizing atmosphere over a range of temperatures for extended periods of time. The oxide layer protects the alloy from the oxidizing atmosphere. Additions of calcium and yttrium are made to the matrix to substantially remove or stabilize oxygen and sulfur dissolved in the molten alloy. These additions result in retention of about 0.005-0.05% of calcium and 0.01-0.06% yttrium in the cast alloy. The matrix further includes about 2-8% iron to inhibit nucleation and growth of a "gamma prime" nickel aluminum intermetallic compound which would otherwise adversely harden the alloy and cause local disturbance of a uniform distribution of aluminum. The alloy has a VHN below about 350.

Abstract: A multi-wire self-diagnostic thermocouple having three thermocouple elements enclosed in a sheath and insulated therefrom. The three thermocouple elements are electrically connected to each other to form three thermocouple junctions. An electronic circuit response to the three EMF signals generated by the three thermocouple junctions generates an error signal when the ratio between the three EMF signals differs from predetermined ratios signifying that the calibration of at least one of the three thermocouple elements has changed. In the preferred embodiment, the sheath is a metal sheath and the three thermocouple elements are fused to each other and to the metal sheath.

Abstract: A method for making thermocouple wire from powdered alloys and metals. The metal or alloy is atomized from its liquid state into a powdered state as it leaves a melting vat. The powder is then compacted and cold worked to form thermocouple wire. Different lots of a powdered alloy or a powdered metal may be blended to reduce the calibration error of the resultant thermocouple wire.

Abstract: An electrode material for a spark plug 10 for use in an internal combustion engine. The electrode material includes a core 20 having a high thermal conductivity for reducing the temperature of the spark plug 10 by thermally conducting heat away from the spark plug gap to a cooler part of the engine. The core 20 extends continuously from an arcing surface at an end of a spark plug electrode to the cooler part of the engine. Surrounding the core 20 is a cladding layer 22 for resisting corrosion when exposed to high temperatures caused by arcing.

Abstract: A fill tube for filling a seam-welded tube with a ceramic powder as the seam-welded tube is being made by a tube making mechanism. The fill tube has a guide tube for directing the ceramic powder from a location upstream of a seam welder to a location downstream of the seam welder. A mounting bracket is attached to the upper end of the guide tube and has a powder channel directing the ceramic powder received from an external powder source into the guide tube and a wire channel directing wires received from an external source into the guide tube. A wire guide is disposed at the opposite end of the guide tube which locates the wires in the seam-welded tube as it is being filled with the ceramic powder.

Abstract: A tubular heating element (10) having a metal tube (12) filled with a ceramic material (14). The metal tube has a near zero or slightly positive temperature coefficient of resistance. In an alternative embodiment, a wire (16) is coaxially supported within the metal tube (12) by the ceramic material (14). This wire may be used to stiffen the tubular heating element (10) or may be used as an electrical conductor.

Abstract: This invention relates to material handling of helical coils of resistance heating wire, hangers for use in handling the wire coils, an assembly of hangers and coils and a method for handling such coils on hangers wherein the manufacture of resistance heating wire can wind and stretch the wire into a coil for a customer, form eyelets at both ends of the coil that are to be used as electrical contact terminals, and then assemble a plurality of coils side by side in a group with eyelets at each end of the coils being on a respective hanger. The hangers have a sleeve-like handle and an integral L-shaped rod arranged so that the coils can be mounted on the hanger by slipping the rod through the eyelets. The assembly of a pair of hangers and a group of coils can then be shipped as a unit to the customer where the customer need only remove the group of coils as a unit and mount the hangers on a T-shaped rack by slipping the handles over posts on the rack.