Diaphragm Sensor Differential Pressure Gauges These diaphragm sensor differential pressure gauges measure the pressure difference between two points. Acting in the place of two pressure gauges, these units allow for one simple reading on an easy-to-read scale. Popular in filtration, flow and level applications, they are a low cost alternative to bourdon tube and bellows designs. Our 1516 Series models are our most popular diaphragm sensor design. They combine a highly sensitive sensor with high line pressure capabilities. We offer them with bodies (and wetted parts) of aluminum, stainless steel or brass. A variety of dial sizes are also available, from 2.5 inch to 6 inch, with many porting and mounting configurations. Choose from a wide selection of standard options; enough to satisfy any requirement. Our 1800 Series models are our most sensitive sensor designs. While being sensitive they also handle high line pressures up to 150 psi! Note: Select these diaphragm models for air or gas applications or where fluid migration from the high to low pressure ports cannot be tolerated. Switches, Relays, Transmitters A variety of reed switches and relays can accompany the gauges or be supplied on their own, without a dial. SPST switches are offered normally open (N.O.) or normally closed (N.C.). SPDT reed switches also are available. DPDT relays are offered for high inductance applications, such as those incorporating motors or solenoids. Transmitters offer a current or a voltage output. Features Low DP ranges at high line pressures Rugged, weatherproof design Gauge, switch and transmitter versions Popular in filtration, flow and level measurements