Prism electronics provides ultra sensitive gas detectors [model xp-702] manufactured by cosmos of japan. These instruments are classified as intrinsically safe, high sensitive leak detectors for combustible and toxic gases. They easily and quickly locate leaks in pipes and fittings where conventional methods, such as soap solutions, are impracticable. The gas detectors are adjustable and high enough to test above ground for leaks in underground pipelines as well as concentrations as small as 10 ppm. They are extensively Used not only by the gas industry, but also by many other branches of industry where combustible gases or vapours are used. The instruments are unique type detectors, which open up a new concept of gas leak detectors. Some of the salient features include: sensitive enough for above ground leak test, audio visual alarm frequency in direct proportion to the gas concentration; handheld, portable with automatic pump; and long sensor life, compact and lightweight, fully intrinsic, safe and ruggedly constructed. The ultra sensitive gas detectors are used in gas as well as other industries where combustible gases or vapours are used.