Methods of making an improved sensing element and an improved sensor assembly for a halogen gas leak detector

Methods are described for making an improved sensing element and an improved sensor assembly for a halogen gas leak detector. The method of making an improved sensing element includes positioning at least one porous ceramic tubular element doped with sodium carbonate in a high temperature, non-reactive container, surrounding and covering the element with sodium beta-alumina particles, and baking the element in a furnace overnight at a temperature in the range from 1400 DEG C. to 1450 DEG C. The method of making an improved sensor assembly includes the above steps after which a helical heater coil is wrapped snugly around the tubular element, and a platinum wire electrode is positioned substantially within and supported by the tubular element. A suitable cement is applied over the entire helical heater coil and the immediate juxtaposed portions of the tubular element. The sensor assembly is then surrounded by and covered with sodium beta-alumina in a high temperature, non-reactive container. The cement is then cured at 1300 DEG C. for one to three hours.