Differential Pressure Gauges and Switches for every need. Mid-West Instrument has been serving a variety of industries (Power, Chemical, Petro-Chemical, HVAC, Water, Filtration) for over 45 years. Over 500,000 Piston Type units have been produced bearing the Mid-West name or private branded for our OEM customers!

Mid-West's forte is flexibility and quick response. Standard configurations can be customized and modified to suit a customer's need for easy installation or retrofit.

Differential Pressure is sensed by the movement of a precisely ground floating piston/magnet in a precision bore against a calibrated spring. Any variation in pressure on either side of the piston/magnet will cause the magnet to move proportionally to the change in differential pressure. A rotary pointer magnet located close to the internal magnet, but outside the pressure housing, follows the movement of the piston magnet and indicates differential pressure on the dial.

Piston-Type Differential Pressure Gauges are available with one or two hermetically sealed reed switches. The switches are adjustable within a defined percentage of the full scale range of the gauge and are available in SPDT and SPST, normally open or normally closed configurations for various load/power ratings. The switches can be set to activate or deactivate on rising or falling pressure. Switches are "CE" marked per the EU low voltage directive.

The model 120 can be configured for use in hazardous locations. All hazardous location switches are both CSA and UL listed. The CSA & UL listings are for the entire assembly and not just the enclosure.