The Henry G. Dietz Co. Inc.

The Dietz Model 85S differential pressure switch is 2 in. square (50 mm square) and can operate on pressures as small as 0.005 in. water column (or 3/1,000 of an ounce per square inch). There is no on-off switch differential pressure. The switch can be operated from 5 V DC, 24 V DC or 120 V AC to actuate relays that have a life that exceeds the life of microswitches. When used with low voltage electronic circuits, such as 5 VDC, the switches can have an almost unlimited life.