The device operates as follows: The flowing medium presses against the paddle of the KOBOLD flow switch. The paddle is fitted to one end of a balance arm which is in direct contact with a pre-stressed leaf spring. At the other end of the balance arm is a permanent magnet. This magnet actuates a reed contact located within a moveable housing outside the media.
The reed contact switches on or off depending on the position of the permanent magnet and the switch housing. The status of the switch may then be used to electrically control the fluid flow. The movable reed switch on the Kobold PSR/PS allows the contacts to be set either normally open (N/O) or normally closed (N/C).
Frequently found in applications where monitoring for zero or low flow is critical, to prevent equipment damage by running dry.