How To Select A Proper Pressure Sensor?
Pressure Sensors are designed to monitor the changes in pressure for liquid and gas applications. Pressure measurement is found in many different applications in various industries. Accordingly, there are many types of pressure sensors, which makes the selection process complicated so you might find the following selection tips useful. Please bear in mind that there are a lot of variables to consider, but here the most critical elements are highlighted. Please look at our glossary if you are not familiar with any of the sensor terms.
- Pressure Range: Generally selection of sensor with the range of 20-30% more than maximum applied pressure is suitable. Specify Line Pressure in case of a differential sensor.
- Pressure Unit: bar, kPa, psi and mmH2O
- Pressure Reference: is the pressure on the reverse side of the diaphragm and can be absolute, vented gauge, sealed gauge or differential
- Output Signal: mV/V, voltage analogue (0-10VDC or others), current (generally 4-20mA) and digital output. Digital output has options such as RS232, CAN Bus, or USB
Note: Generally, sensors with mV/V output are called transducers and sensors with VDC or current output called transmitters.
- Accuracy: Is generally a percentage of full range so there is a trade off in accuracy and the range of measurement. Also consider Accuracy at Room Temp or Max. Total Accuracy Over Temp Range of use.
- Electrical Connection: DIN connector, Cable, wireless, etc.
- Pressure Connection Port: Male/Female, NPT, ISO, BSP, etc.
- Media Compatibility and Ambient Environment:
Gas, Condensing, Liquid, Corrosive, High Viscosity, Abrasive, Hygienic, Oxygen Service, Chemicals, NACE (Offshore), Wastewater, Concrete / Aggregate / Slurry, Landfill, Petrol / Diesel, Plastic Melt, High Purity Gas, Indoor / Outdoor Use, Inside Electronics Enclosure, Occasional Immersion / Hose Down, Submersible, Sea-Water / Salt-Water, Salt Spray / Sea Air, High Humidity, High Vibration or Shock, High External Case Pressure (Subsea), Water Jet Cleaning, High Pressure Steam Cleaning, etc.
- Temperature limitations: (Highest Media Temperature at Sensor, Lowest Media Temperature at Sensor), High Temperature, Low Temperature
- Sensor Supply Voltage
- Sensor Dimensions: Max. Diameter of Sensor, Max. Length of Sensor
- Other considerations: Certificate of Conformity, Intrinsic Safety, Lightning Protection, Frequency Response, Display, Zero & Span Adjustment, non-technical parameters (Quantity, Max Delivery Time, After Sales Services, support for long term needs, cost of ownership), etc.
During installation and commissioning of the sensor, consider below items as well:
- Avoid Zero distortion by monitoring the pressure during installation and preventing any overload.
- Utilize O-ring or seal where recommended.
- Avoid dropping, overloading, abusing or handling pressure sensor by cable.
- Make sure that the output of the pressure sensor you are getting is compatible with your logger or controller you intend to use it with.
In a case of any question, you can simply send an email to Sales@MeasureX.com.au for any detailed information and advice on this issue.