Pressure transducers, pressure gauges and differential pressure transducers

Pressure sensors, pressure gauges & pressure switches

Accurate monitoring of pressure in industrial systems

Sensors and instruments for accurate measurement and monitoring of pressure in industrial systems, ventilation systems and process applications.

At Swelex, you’ll find electronic pressure transmitters, differential pressure transmitters and mechanical pressure gauges for everything from industrial processes to building automation and cleanrooms.

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Pressure transducer

Electronic pressure sensors convert pressure into an electrical signal (e.g. 4-20 mA or 0-10 V) for integration into control and monitoring systems.

GEMS Pressure sensors - Series 3100 / 3200

Robust pressure transducer for industrial environments where high accuracy and reliability are required.

  • Measuring range from 7 bar up to 0-2 200 bar
  • Stainless steel media related parts
  • Multiple electrical outputs and connections
  • IP65-rated connections
  • High EMC resistance
  • RoHS compliant


GEMS Pressure Sensor Series 3500

Compact pressure transducer with high accuracy & fast response, ideal for limited space.

  • Measuring range up to 16 bar
  • 316 stainless steel
  • Accuracy up to 0.25 % FS
  • Long-term stability <0.2 %
  • Multiple electrical outputs
  • Operating temperature up to 125 °C


GEMS 3510 Pressure sensor

Compact pressure sensor for OEM applications and battery powered systems.

  • Pressure range up to 60 bar
  • MEMS technology for fast and accurate measurement
  • Accuracy ±0.5 % FS
  • 316 stainless steel
  • Multiple electrical outputs
  • Operating range -40 °C to +100 °C

Metallux Pressure Sensor Series ME900

Monolithic ceramic pressure sensor for harsh industrial environments.

  • Pressure range up to 5 000 bar
  • Ceramic sensor cell
  • Output signal 0.5-4.5 V ratiometric
  • Electronic temperature compensation
  • High chemical resistance
  • Long-term stability


Metallux ME504 Pressure sensor

Ceramic piezoresistive pressure sensor with high chemical resistance.

  • Pressure range 1-800 bar
  • Ceramic measuring cell
  • Piezoresistive measurement technology
  • High resistance to aggressive media
  • Thermally compensated measurement
  • Low hysteresis and high stability

Differential pressure transducer

A differential pressure transducer measures the pressure difference between two points and is often used in ventilation systems, filter monitoring and flow measurement. They are key components in building automation, the process industry and cleanroom technology.

differential pressure transducer
BECK Differential pressure sensors - Series 984

Differential pressure sensor for air and gases, suitable for ventilation systems and filter monitoring.

  • Selectable output signal 4-20 mA or 0-10 V
  • Adjustable response time
  • Two optional printing areas
  • Available with or without display
  • Easy installation
  • Stable metering for HVAC systems


BECK Differential pressure sensors - Series 985

Digital differential pressure sensor for industrial environments and building automation.

  • LED display
  • Modbus alternative
  • 4-20 mA or 0-10 V output signal
  • IP65 enclosure
  • Pressure range up to 100 kPa
  • For air and non-aggressive gases


DWYER Magnesense - MSX Series

A differential pressure sensor designed for ventilation and building automation.

  • LCD display
  • 4-20 mA or 0-10 V output signal
  • Quick installation
  • Stable and accurate measurement
  • Plenum rated construction
  • Suitable for HVAC systems


DWYER Digihelic - DHC Series

Differential pressure transmitter with an integrated display and multiple functions in a single unit.

  • 3-in-1 function (measurement, display and signal output)
  • 4-20 mA output signal
  • Accuracy <1.5 %
  • Stainless steel construction
  • Secure menu programming
  • Suitable for industrial applications

Pressure gauges & monitoring

Mechanical pressure gauges and monitoring instruments are used when pressure needs to be displayed visually or when a system needs local monitoring without advanced electronics.


DWYER Magnehelic Series 2000

One of the world’s most widely used differential pressure gauges

  • Mechanical differential pressure gauge
  • Frictionless measuring mechanism for fast & stable reading
  • Handles both positive, negative & differential pressure
  • Robust construction that withstands shock, vibration & overpressure
  • Wide measurement range for air and gases
  • Common in HVAC systems, filter monitoring and cleanrooms


Dwyer DigiMag DM-1000

Digital differential pressure and flow meter for filter monitoring, cleanrooms and ventilation systems.

  • Digital readout with 4-digit LCD
  • Battery or 24 V operation, easy installation
  • Directly interchangeable with existing Magnehelic installations
  • Factory calibrated for high accuracy
  • Used for pressure, flow, vacuum and duct/room monitoring
  • Easy menu control and calibration


Dwyer 3000 MR/MRS Photohelic

Combines differential pressure gauge with alarm functions, ideal for HVAC and cleanrooms.

  • High accuracy analogue display
  • External adjustment of low & high limits with large knobs
  • Solid-state design, low weight & compact size
  • Electrical relays, gold-silver contacts, high cycle capacity
  • Up to 25 psig (1.7 bar)
  • Can be recessed or surface mounted


DWYER RPMC - Room pressure monitor

Differential pressure monitoring systems in critical environments such as cleanrooms, laboratories and pharmaceutical production.

  • Accurate measurement of low differential pressure
  • LED indication for status and alarm
  • 2 SPDT relays for alarm signal
  • Process output 4-20 mA
  • Logging of peak and trough values
  • Password-protected settings
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FAQ – Pressure, Differential Pressure and Pressure Switches

  • What is the difference between pressure sensors, pressure gauges and pressure switches?

    • Pressure sensors (transmitters): Converts pressure into electrical signal (e.g. 4-20 mA) that can be read by control systems. Used for continuous monitoring.
      Pressure gauge: Displays pressure visually, often with analogue scale. Can be simple or differential (Magnehelic, DigiMag).
      Pressure switch: Activates alarm or control signal when pressure reaches set point, e.g. Dwyer 3600 series.

  • What is a differential pressure transducer/gauge?

    • The measurement difference between two points (e.g. before and after a filter).
    • Used for ventilation systems, filter monitoring, cleanrooms and building automation.
    • Can indicate both positive and negative pressure conditions.
    • Available in analogue (Magnehelic) and digital (DigiMag, 3000MR/MRS).

  • Which media can be measured using pressure transmitters and differential pressure transmitters?

    • Air, gases and non-corrosive liquids.
    • For aggressive liquids or high temperatures, stainless steel or ceramic models are available.
    • Always check the sensor specification for compatibility with the print medium.

  • How do you install a pressure sensor or differential pressure gauge?

    • Choose the right measurement area and connection type.
    • Install the sensor according to the flow direction and environmental requirements.
    • Ensure that wiring and signal outputs are correctly connected to control systems.
    • For differential pressure: connect the high- and low-pressure sides correctly.

  • What are Magnehelic and Photohelic metres?

    • Magnehelic (2000 series): Analogue differential pressure gauges with frictionless indicator. No power supply needed, resistant to shock and vibration.
    • Photohelic (3000MR/MRS series): Combines analogue reading with alarm function (switch) for low and high pressure. Solid-state technology provides high cycle rate and accurate measurements.

  • Can differential pressure transmitters be used in cleanrooms?

  • Yes, many models are designed for cleanrooms and critical environments (e.g. Dwyer Magnesense MSX/Pro and DigiMag DM-1000). Features may include alarms, peak/trough logging and a display showing real-time values, for example: the RPME series for room pressure monitoring.

  • What are the advantages of digital differential pressure transmitters compared to analogue ones?

    • Direct digital readout, often with LCD display.
    • Easy integration with control systems via 4-20 mA, 0-10V or Modbus.
    • Quick installation and calibration.
    • Possibility to replace existing analogue Magnehelic meters directly.

  • How do you calibrate a pressure transducer or differential pressure gauge?

    • Calibration is against a known reference and adjusts the output signal for accurate reading.
    • Some models can be calibrated on site (DigiMag, 3000MR), others require factory calibration (Magnehelic, Metallux).
    • Calibration certificates can usually be ordered as an option.

  • What factors influence the choice of a pressure or differential pressure transducer?

    • Measurement range and accuracy
    • Medium and chemical resistance
    • Operating temperature and environment (IP rating)
    • Output and connectivity
    • If alarm function is needed (pressure switch vs. continuous monitoring)

  • How do room pressure monitors (RPMC, RPME) work?

    • The measurement difference between room and reference (e.g. corridor) is converted into alarm or signal.
    • May have display and relays for overpressure or underpressure alarms.
    • Used in hospitals, laboratories and cleanrooms for safe operation.

  • Can pressure switches and differential pressure transmitters be used with HVAC systems?

    • Yes, common applications include filter monitoring, fan control, duct pressure monitoring and energy saving HVAC systems.
    • Differential pressure sensors ensure optimal flow balance and allow maintenance to act before problems occur.

  • What is the difference between analogue and electronic pressure switches?

    • Analogue pressure switches (e.g. Magnehelic) have a mechanical indicator and do not require power supply.
    • Electronic pressure switches (e.g. Dwyer 3600 series) have no moving parts, are shock resistant and can be programmed with precise deadband.