Filter monitoring device which monitors differential pressure and temperature

摘要

A filter monitoring device for use in monitoring the purity of a fluid through a filter includes a pressure differential sensing device in communication with the filter. The filter monitoring device defines an inlet port which is in communication with the supply of fluid upstream of the filter and an outlet port which is in communication with a supply of fluid downstream of the filter. The differential pressure sensing device comprises at least one movable device which is in contact with both the upstream and downstream supplies of fluid and moves in response to changes in the pressure differential of the fluid. Different total differential pressures are accommodated by corresponding stiffness of a biasing device. The differential pressure sensing device also comprises a distance sensing device which continuously measures or detects the distance of travel of the movable device. The distance sensing device is operatively connected to at least one indicator device which conveys or transmits the status of the pressure differential of the fluid in the filter assembly.