DWYER INSTRUMENTS 1950 Series Explosion-proof Differential Pressure Switches

Dwyer Instruments 1950 Series explosion-proof differential pressure switches monitor and control pressure differentials in hazardous environments with a risk of explosion. These switches are ideal for the oil & gas, chemical processing, mining and petrochemical industries.

Connection Size: 1/8" , Connection Type: NPT , Electrical Connection: NO/ NC , Enclosure Rating: NEMA 3, NEMA 7, NEMA 9 , IP Rating: IP 54 , Switch Type: SPDT
StyleModelApprox Deadband Max. Set PointApprox Deadband Min. Set PointContinious PressureSurge PressurePrice (ex. VAT)
1950P-2-2F bar3.45 bar€479.08
1950-5-2F bar0.69 bar€420.76
0.500.40.11 bar0.69 bar€420.76

Working Mechanism

  • Ensure that the gauge is mounted securely in a location free from excessive vibration & corrosion.
  • Connect the pressure sources to the appropriate ports of the gauge using suitable tubing or piping.
  • Confirm that the pressure sources are correctly connected to the high and low-pressure ports of the gauge. The high-pressure port typically connects to the source of greater pressure, while the low-pressure port connects to the source of lower pressure.
  • Once the connections are established, apply pressure to the gauge system and observe the reading on the gauge display.
  • The differential pressure is measured by observing the difference in pressure between the high and low-pressure ports.
  • Take note of the unit of measurement displayed on the gauge and interpret the differential pressure reading accordingly.


  • These switches can operate within a temperature range of -40 to 140 degrees F.
  • They have different enclosure ratings, including NEMA 3 (IP54), NEMA 7 and NEMA 9, offering superior protection in hazardous environments.
  • They feature a single-pole double-throw (SPDT) switch configuration for common, normally open and normally closed contacts, ensuring a secure and reliable electrical connection.
  • These switches have 1/8-inch female NPT process connections and can be easily integrated into the pressure system being monitored.
  • They feature a screw-type set point adjustment mechanism located on the top of the housing, allowing for easy and precise adjustment of the pressure set point.

Standards and Approvals

  • CE
  • CSA
  • UL
  • FM

Frequently Asked Questions

How to install these Dwyer differential pressure switches?

  • Select a location that is free from excess vibration and corrosive atmospheres.
  • Mount the standard switches with the diaphragm positioned in a vertical plane.
  • Make sure that the switch lettering and nameplate are upright.
  • Connect the switch to the source of pressure, vacuum or differential pressure.
  • Join the tubing to the two 1/8-inch female NPT pressure ports.
  • Connect pipes or tubes from the source of greater pressure to the high-pressure port marked HIGH PRESS and from the source of lower pressure to the low-pressure port marked LOW PRESS.

How to change the set point of these differential pressure switches?

  • Remove the plastic cap located at the top of the housing by carefully pulling it off.
  • Locate the slotted adjustment screw underneath the plastic cap. This screw is used to change the set point pressure of the switch.
  • To increase the set point pressure, turn the screw clockwise (to the right). To decrease the set point pressure, turn the screw counterclockwise (to the left).
  • Make adjustments to the set point slowly and carefully to ensure accurate calibration.

What is the difference between a differential pressure gauge and a pressure gauge?

A differential pressure gauge measures the difference in pressure between two points, whereas a standard pressure gauge measures the pressure at a single point in a system. Differential pressure gauges are used to monitor pressure differentials, while pressure gauges are used to measure absolute or gauge pressures.

How do I select the right differential pressure gauge for my application?

When selecting a differential pressure gauge, consider factors like the pressure range, accuracy requirements, environmental conditions and compatibility with the measured media.

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