Magnetic detector for pressure and density decrease of the insulation gas of an electrical apparatus

摘要

Device comprises bellows (14) within a tank (12), with a first permanent magnet (20) attached to one end of the bellows and a second (22) coupled to the first across a non-magnetic wall (18). Each magnet is cylindrical with radial polarization allowing movement of the magnets along either side of the wall when the bellows expands or contracts. A triggering or signaling device (36,38) is coupled to the second magnet to indicate a lowering of the density or pressure of the gas within the tank.