A Diaphragm — or Pressure — Switch works by activating a sensitive micro-switch when material reaches the level of the Switch in the bin. It sends an alert that can be used to start or stop a process, or alert to a high, medium or low level in the vessel. Commonly used in grain, feed, seed or other granular materials, Diaphragm Switches are offered for either internal or external mount, can be wired to a light, horn, alarm, or a point level alarm panel to indicate an alert status.