Information Technology IT – 3 Monitoring and control | e-Consult

Several types of pressure sensors exist, each employing different physical principles to measure pressure:

• Strain Gauge Pressure Sensors: These sensors utilize strain gauges bonded to a diaphragm. Pressure causes the diaphragm to deflect, straining the gauges. The strain gauges' resistance changes proportionally to the strain, which is then converted to a voltage change using a Wheatstone bridge circuit.
  Best for: Measuring static pressure in industrial applications, such as pressure vessels and hydraulic systems.
  Output Signal: Voltage change (typically a small DC voltage).
• Piezoresistive Pressure Sensors: These sensors incorporate piezoresistive materials (e.g., silicon) that exhibit a change in electrical resistance when subjected to mechanical stress (pressure). The pressure directly deforms the piezoresistive element, altering its resistance.
  Best for: Measuring dynamic pressure changes, such as in engines or pneumatic systems. They are also suitable for high-frequency pressure measurements.
  Output Signal: Change in resistance (requires signal conditioning to convert to a voltage).
• Capacitive Pressure Sensors: These sensors consist of two capacitor plates separated by a diaphragm. Pressure causes the diaphragm to move, changing the distance between the plates and thus altering the capacitance.
  Best for: Measuring low-pressure changes, such as in medical devices or environmental monitoring. They are also less susceptible to drift than other types.
  Output Signal: Change in capacitance (requires signal conditioning to convert to a voltage).