Mid-West® Instrument Piston ΔP Gauges- A precision ground magnetic piston assembly moves against a calibrated range spring in a diamond reamed bore in the gauge body as pressure differential between the high and low ports changes. A rotary magnet on the outside of the body tracks the movement of the magnetic piston and the attached pointer indicates ΔP on a dial.

All piston type gauges allow process fluid to migrate across the piston from high to low side. The precision machining of Mid-West® Instrument piston ΔP gauges limits the migration to a maximum of 15 SCFH air at 100 PSID at ambient conditions. For applications where fluid migration from high side to low side is not tolerable select one of our many Diaphragm type ΔP gauges

Piston-Type Differential Pressure Gauges are available with one or two hermetically sealed reed switches or 4-20mA transmitter depending on model. 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 and ROHS Directive.