Patent ID: 9201033
Filing Date: 2015-12-01
Classification: G01N

Abstract:
1. A water-concentration detection device configured to detect a water concentration of insulating gas filled in a gas-insulated device, the water-concentration detection device comprising: a gas chamber that introduces the insulating gas from the gas-insulated device via a pipe provided with a first valve that controls the amount of insulating gas that enters the gas chamber, and the gas chamber encloses therein the insulating gas; electrodes that are porous and are arranged to face each other within the gas chamber; a solid electrolyte membrane that is hydrogen-ion conductive and is held between and fixedly attached to the electrodes; an impedance measurement unit that measures an alternating-current impedance between the electrodes by applying an alternating-current voltage to the electrodes; a water-concentration detection unit that detects the water concentration of the insulating gas based on the alternating-current impedance measured by the impedance measurement unit; and a drying unit arranged on a downstream side of the solid electrolyte membrane with respect to a direction in which the insulating gas is introduced into the gas chamber, wherein (1) the drying unit removes water from an atmosphere in the gas chamber in a state in which the first valve is closed so that no insulating gas enters the gas chamber; (2) the insulating gas is subsequently introduced into the gas chamber from the gas-insulated device in a state in which the first valve is opened; and (3) the water-concentration detection unit detects the water concentration of the insulating gas after the first valve is opened and the insulating gas is introduced into the gas chamber.