The M-100 has been engineered to monitor vital sample flow parameters for instrumentation in process control and inert blanket gases. It serves as an auxiliary alarm monitor for flow meters and suited for applications when installed on a by-pass for determination of filter plugging. The M-100 is available in 1/8" FNPT and 1/4" FNPT sizes in stainless steel. The flow switch has a water flow range of 35 to 2,000 ml/min and an air flow range of 700 to 65,000 sccm.

The magnetic piston rests at the bottom of the switch with no flow present. Once flow is established, the piston moves upward responding to a by-pass flow and actuates the reed switch. The by-pass flow is controlled by a manual adjusting screw controlling the variable orifice. When flow decreases, the piston moves downward and the reed switch deactuates. Set point accuracy is ±10%, repeatability ±5%, hysteresis ±15-30%. Applications include gas and liquid analyzers, atmosphere furnaces, CVD tools, and vacuum systems.