Dwyer 3000MR-00 Photohelic Differential Pressure Switch-Gauge Range: 0-0.25″ w.c.

Dwyer 3000MR-00 Photohelic Differential Pressure Switch-Gauge Range: 0-0.25″ w.c.

Pressure Switch/Gage, Range 0-0.25″ w.c., .005 minor divisions.


Series 3000MR Photohelic® Switch/Gage, Additional Range 0-0.25″ w.c., Relay Type – Electromechanical Relays


  • mounting ring, snap ring
  • 18″ cable assembly
  • (2) 3/16″ tubing to 1/8″ NPT adapters
  • (2) 1/8″ NPT pipe plugs
  • (4) 6-32 x 1-1/4″ RH machine screws (panel mounting)
  • (3) 6-32 x 5/16″ RH machine screws (surface mounting)

The Series 3000MR Photohelic® Switch/Gage combine the functions of a precise, highly repeatable differential pressure switch with a large easy-to-read analog pressure gage employing the durable, time-proven Magnehelic® gage design. Switch setting is easy to adjust with large external knobs on the gage face. Gage reading is unaffected by switch operation – will indicate accurately even if power is interrupted. Solid state design now results in greatly reduced size and weight. Units can be flush mounted in 4-13/16″ hole 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. Model provide both low and high limit control and include 18-inch cable assemblies for electrical connections.

Gage accuracy is ±2% of full scale and switch repeatability is ±1%. Switch deadband is one pointer width – less than 1% of full scale. Compatible with air and other non-combustible, non-corrosive gases, they can be used in systems with pressures to 25 psig.


  • Fan Control
  • Damper Control
  • Environmental Pollution Control