When it comes to pressure sensors, there is a tremendous number of choices available in today’s marketplace. All the different measuring technologies and principles that are promoted by manufacturers can make choosing the correct one a seemingly impossible task. Here we can help you to learn more about the different technologies available and how we can help you to select the optimal solution for any application. 

 

Function of a Pressure Sensor

Thin Film Pressure Sensors

Pressure Sensors (or pressure transducers) are components that work by converting an actual pressure value into an electrical signal. Pressure sensors are available with a variation of different sensing elements and respond to the force applied to this element by gas or liquid pressure. The force applied to the element is then measured and converted into an electrical output signal, allowing it to be monitored by PLCs, processors and other computers.

 

Pressure Sensing Technologies

There are many different pressure sensing technologies available on the marketplace today. Some of the most commonly produced technologies by manufacturers across the world are as follows:
 

  • Capacitance Type – Capacitance type pressure sensors are often favoured by high volume OEM specialty applications. Detecting the capacitance change between two surfaces allows these transducers to sense extremely low pressure and vacuum levels. In our typical sensor configuration, a compact housing contains two closely space, parallel, electrically isolated metallic surfaces, one of which is essentially a diaphragm capable of slight flexing under pressure. These firmly secured surfaces (or plates) are mounted so that the flexing of the assembly alters the gap between them (creating, in effect, a variable capacitor). The resulting change is detected by a sensitive linear comparator circuit with (or ASICs) which amplifies and outputs a proportional high-level signal.
     
  • CVD Type – Chemical Vapour Deposition (or “CVD”) manufacturing methods bond a polysilicon layer to a stainless steel diaphragm at the molecular level to produce a sensor with superior long term drift performance. Common batch processing semiconductor manufacturing methods are used to create a polysilicon strain gauge bridge with terrific performance at a very reasonable price. CVD construction offers excellent price/performance and is the most popular sensor for OEM applications.
     
  • Sputtered Thin Film Type – Sputtered film deposition (or “thin film”) creates sensors with maximum combined linearity, hysteresis and repeatability. Accuracy can be as high as 0.08% full scale with long term drift as low as 0.06% full scale per year.  Phenomenal performance for critical instruments – our sputtered thin film sensors are the jewels of the pressure sensing industry.
     
  • MMS Type - These sensors employ a micromachined silicon (MMS) diaphragm to detect pressure changes. The silicon diaphragm is protected from the media by an oil-filled 316SS isolation diaphragm and they react in tandem to process fluid pressure. MMS sensors utilise common semiconductor manufacturing techniques that allow for high proof pressure, good linearity, great thermal shock performance and stability in a compact sensor package.

 

Units of Pressure Measurement

Pressure is one of the most important physical state variables. The pressure is defined as a force (FN) which acts consistently over a defined area (A). The different types of pressure are separated only by the reference pressure. The 4 main types of pressure measurement used within sensing technologies are:
 

  • Gauge (G) – is measured in reference to atmospheric pressure.
     
  • Sealed (S) – is measured in reference to a sealed tank or vessel with atmospheric pressure.
     
  • Absolute (A) – is measured in reference to vacuum.
     
  • Differential (D) – is measured across two different points within a system.
     

For more information on the different units of pressure measurement and how to select which type you need, please do get in touch with us here. 

 

Specifications of Pressure Sensors

There are many different technical factors to consider in and around your application, when looking into selecting a suitable pressure sensor. Aside from establishing your application, you will need to consider the following:
 

  • Output – which output signal should be used to convert the pressure reading? Typically, we see analogue or voltage as being the most common requirements. Aside from the more standardised 4 to 20 mA, 0 to 10 V or 0 to 5 V you may need to consider looking at millivolt output (unamplified), ratiometric, I2C, NPN/PNP with IO-Link, Modbus or CANbus/CANopen.
     
  • Connection – how will the pressure sensor be physically connected into the system? Also referred to as the “pressure port”, we can offer from standard BSPP, BSPT, NPT, Metric or SAE threads to more bespoke connections such as VCR FaceSeal™, Surface Mounting or KF Flanged for UHP Applications to Nose Cone/Sink Weights for Submerging in Tanks.
     
  • Termination – what electrical connection should be used to receive the signal? Whether it be a standard DIN connection (From Large DIN Type A to Mini DIN Type C), an M12 x 1P (multiple PIN options), 1/2” NPT Conduit or Cabled (according to length required), we have got you covered.
     
  • Operating Parameters – what parameters will the unit be required to operate under? What is the actual pressure range needing to be measured? What is the media and temperature? What conditions will the unit be installed in (eg. outdoor environment)?
     
  • Special Considerations – are there any special conditions that may affect the choice of unit? Will the unit be susceptible to vibration? Are there any specific cleaning or testing standards needed? Are you using a particularly aggressive media, such as Hydrogen? Is there a chance the unit will see pressure spikes? The more detail we have, the better we are able to advise you.

 

Pressure Sensor Applications

Pressure sensors are one of the most sought out instruments, used across a huge variety of industries and applications. We’ve got you covered with some of the industries largest selection and best choice of technologies. Some of the typical applications we work with include:
 

  • Off-Highway Vehicles - Load Weighing Systems and Load Moment Indicating
  • Natural Gas Equipment - Compressors and Dispensing Equipment
  • Semiconductor Processing - Water Manufacturing
  • Power Plants - Piping Steam Pressure
  • Refrigeration - Compressors and Lube Oil Pressure Equipment
  • Robotics - Factory Automated Equipment
  • Test & Measurement - Dynamometers, Medical Instrumentation, Wind Tunnels
  • Barometric - Altimeter certification, Weather Stations
  • HVAC - Compressors, Filter Monitoring, Energy Management
  • Transportation - Breaking, Compressors, Lifts, Air Conditioning

 

Pressure Sensor Stockist in the UK

Our enormous selection of pressure sensors features an extensive range of options, technologies and configurations to meet the most demanding applications. To explore our full range of pressure sensing solutions, please visit our category page here.
 

For technical support on selecting the right sensor for your application, get in touch with our experienced engineers here.
 

Looking for a quick delivery? To view our selection of pressure sensors in-stock and readily available for next-day delivery, click here to see our intuitive part number configuration.