Photohelic gauge switch (SERIES 3000MR & 3000 MRS) uses solid state technology and combines the functions of a precise, highly repeatable differential pressure switch with a large, easy-to-read analog pressure gauge employing the durable, time-proven Magnehelic gauge design. The switch setting is easy to adjust with large external knobs on the gauge face. The gauge reading is unaffected by the switch operation and will indicate accurately even if power is interrupted. Solid state design now results in greatly reduced size and weight. Photohelic gauge switch units can be flush-mounted or surface-mounted with hardware supplied. 3000MR models employ versatile electromechanical relays with gold over silver contacts, ideal for dry circuits. For applications requiring high cycle rates, choose 3000MRS models with SPST (N.O.) solid state relays. All models provide both low and high limit control and include 18-inch (45 cm) cable assemblies for electrical connections.

Photohelic gauge switches are compatible with air and other non-combustible, non-corrosive gases, they can be used in systems with pressures up to 25 psig (1.725 bar). Optional construction is available for use at either 35 psig (2.42 bar) or 80 psig (5.51 bar).