Pressure difference indicator, for lower pressure in e.g. ventilation installations, comprises preferably rubber membrane in center of which metal plate is cast fitting between two gables

摘要

The membrane separates two spaces each provided with air hoses for connection to the building rooms with different pressure. On the establishment of an imbalance between the pressures, the built-in material tension and the weight of the membrane related to its inclination can approach or remove the membrane central plate to or from the inductive indicator screwed into the center of the gables, the contact position of which depends upon the proximity to the metal plate. The membrane is molded in one piece so that it is surrounded by an outer powerful ring with two thickness levels, an inner which defines the depth in the pressure chamber created by the membrane and the gables and an outer which creates circular control edges for the gables. The plate-shaped pressure indicator is suspended with the plate in the vertical plane.