Abstract: A halogen gas detector comprises a coil comprising an oxidation-resistant metal wire with a nonreactive oxide coating wound into a double helix defining a cylindrical space, a conductive metal pin positioned within the cylindrical space making no contact with the coil, finely divided sintered in place sodium titanate filling the space between the coil and the pin.

Abstract: A gas detector apparatus for determining the concentration of a selected one of a plurality of predetermined gases includes a gas sensor which generates a gas output signal related to the concentration of the selected predetermined gas in the gas sample. A K factor storage associated with the gas sensor stores at least one K factor, unique to and generated by using the gas sensor, for each of the plurality of predetermined gases. A processor, in response to a selected gas control signal, selects the K factor or factors from the K factor storage for the selected gas and, in accordance with a predetermined process stored therein, calculates a concentration signal representing the concentration of the selected gas in the gas sample.

Abstract: The present invention is directed towards a low power, solid state gas sensor and method of making the same. The sensor comprises a heating element formed from a wire coiled about an axis, a sensing whisker placed inside the heating coil substantially in plane with said axis, and a metal oxide semiconductor material whose resistance varies with the object gas concentration. The gas sensors of this type operate at less than 150 mA. In addition, gas sensors of the present invention exhibit a substantially linear response over a significant concentration of the object gas.

Abstract: A constant temperature catalytic gas detection instrument (10) has a gas sensor (14) whose operating temperature is maintained within a predetermined range by a novel control circuit. The gas sensor includes a reference element (16) and an active element (18) on which a metal oxide catalyst reacts with the combustible gas. First and second driver circuits (30 and 36) are provided for presenting operating voltages to the active element (18) and the reference element (16), respectively, of the gas sensor (14). The first driver (30) controls the power to the active element (18), to maintain its temperature within a predetermined operating range. The second driver (36) responds to changes in the power through the active element (18) with respect to the current through the active element (18), causing the current in the reference element (16) to track the current in the active element (18).

Abstract: A process for applying a protective light-transmitting coating to a photoflash lamp comprising the steps of applying the protective coating to the lamp and curing the applied coating by exposure thereof to radiant energy and characterized by the improvement wherein the layer of coating applied to some portions of the photoflash lamp is thicker than the layer of coating applied to other portions of the photoflash lamp.

Abstract: For use in a color-corrected photoflash unit, a flashlamp having a clear glass envelope with a transparent protective exterior coating comprising a UV curable photopolymer tinted with a colorant providing a portion of the total color correction capability of the unit.

Abstract: A method of applying a protective light-transmitting coating on the exterior surface of the glass envelope of a lamp, the method comprising: holding the lamp with its longitudinal axis disposed horizontally and rotating the lamp about its longitudinal axis; flow-dispensing a liquid coating material of a predetermined viscosity onto the rotating lamp envelope from a dispensing means including a profiled row of needles located above the lamp; and allowing the envelope coating to be cure-hardened, such as by irradiation. The method is particularly useful for applying an optically clear photopolymer coating on the glass envelope of a photoflash lamp in less than one second and then curing the coating by irradiation with a source of ultraviolet light.

Abstract: A high-voltage type photoflash lamp filled with a filamentary combustible material and oxygen and having a beadless ignition structure comprising a pair of spaced apart lead-in wires with spherically shaped terminations, a glass frit coating over the lead-in wires with scraped-off portions exposing the bare metal of the wire adjacent each termination, and a coating of primer material over the frit-coated terminations and bared portions of the wires. The primer may bridge the wire terminations or comprise separate spaced apart coatings on the respective terminations, with the filamentary combustible being in contact with both terminations to provide a conducting path therebetween. The frit coating is thick enough to prevent preignition short circuits.