ENT 164 Sensors & Measurement

1. ENT 164Sensors & Measurement Measuring Pressure

2. Introduction • 3 different form: • Absolute pressure • Gage pressure • Differential pressure • Units: • British Unit: pounds per square inch (psi) • SI Unit: Pascal (1 Pa = pressure of 1N per square meter)

7. Traditional Pressure Measuring Devices 1) U-tube Manometer • Traditional – no electrical based secondary sensing element • The sensing lines of the pressures to be sensed are connected to the tops of the tubes. • Pressure difference: • Common to express pressure as height of fluid column. • P=ρgh

9. Traditional Pressure Measuring Devices 1) Manometer – Well-type manometer

11. Traditional Pressure Measuring Devices 1) Manometer – inclined manometer

13. Traditional Pressure Measuring Devices 2) Bourdon Gage • Simple device to obtain rapid readings of fluid pressures. • Measuring wide range of pressures from low vacuums to 1500 atm. • Accuracy – 0.5% fs

14. Traditional Pressure Measuring Devices 2) Bourdon Gage Animation

15. Traditional Pressure Measuring Devices 3) Dead-Weight Tester

16. Pressure Transducer 1) Strain-Gage Pressure Transducer in Diaphragm

17. Pressure Transducer 2) LVDT Transducer in Diaphragm

18. Pressure Transducer 3) Capacitive Transducer in Diaphragm

19. Pressure Transducer 4) Piezoelectric Transducer in Diaphragm