The PS91 is a differential pressure switch that is not affected by changes in static pressure (common line pressure). The PS91 is designed for a unique manifold, or supplied with two identical female pressure ports for more general purpose applications. The switch can be adjusted via a central screw on top of the unit. The unit is supplied with a mini DIN connector in keeping with the compact packaging. THIS MODEL FORMERLY KNOWN AS PDAM/PDDA/PDDF.

The PS93 Series' compact design enables them to be mounted in tight spaces. The use of a piston/diaphragm design incorporates the high proof pressure of piston technology with the sensitivity of a diaphragm design. The PS93 series may be field or factory adjusted via a hex screw inside the low port, protecting against unauthorized tampering. THIS MODEL FORMERLY KNOWN AS PJDA/PJDF/PS-D.