GAS SAMPLING APPARATUS

PURPOSE:To prevent fatigue of a cooler due to draining conversion with a limited temperature variation range by controlling the set temperature of the cooler according to water contained in a sampling gas through a dew-point indicator and a manometer. CONSTITUTION:Water content is detected as corrected according to the pressure of the sampling gas through a pressure correction arithmetic unit 11 responding to measured values with a dew-point meter 1 and a manometer 2 on the up and down streams of a piping 6 into which the sampling gas flows. The set temperature of a refrigerator 17 is controlled with a function arithmetic unit 12, a temperature adjustor 14, a D/A converter 15 and the like and water contained in the sampling gas is drained and discharged. Therefore, the temperature variation range of the thermal cycle is selected appropriately to obtain a gas sampling apparatus which can be prevent fatigue of a cooler.