Analyser instrument company provides pragmatic oxygen analysers [model zkg] manufactured by fuji electric systems co, ltd, japan. These are paramagnetic oxygen analysers are dumbbell in shape. Based on that the magnetic susceptibility of oxygen gas, which is larger that coexisting gases, stable measurement is ensured unaffected by coexisting gases. The detector does not have a heating part such as heater. Therefore, the analysers are suited for measuring the oxygen concentration in flammable gas. Further, running cost can be saved since reference gas is not required. Since reference gas is unnecessary due to use of a dumbbell type paramagnetic system, these analysers will not entail an additional running cost. The principle of measurement is dependent on the strong magnetic property of oxygen molecules. Therefore, measurement is almost unaffected by other molecules weaker in magnetic property than oxygen. Other features include suitable for measuring oxygen in flammable gas small-sized and easy to handle used with a wide range of power supplies; and output is linear.