| 摘要 |
A sensor assembly for a halogenated gas leak detector is characterized by having a porous ceramic spacer element positioned around a central electrode and around portions of the turns of a helical heater coil in order to hold these component parts and the respective turns of the coil in fixed, spaced-apart relationship. The central electrode and the turns of the heater coil are formed of fine, closely spaced, flexible wire that must be held in a predetermined position when the sensor is assembled. To construct the sensor pursuant to a preferred method of the invention, a coating of porous ceramic material is deposited and cured on the central electrode and the pores of this coating are loaded with an alkali metal salt. The central electrode is then positioned within the heater coil, from which it is insulated by the coating of ceramic material, and a slurry of ceramic cement is applied to completely surround the coated portion of the central electrode and to at least partially surround each of the turns of the heater coil. The slurry is cured to form a ceramic spacer block that serves to position the central electrode and the respective turns of the heater coil in fixed spaced-apart relationship.
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