1. LECTURER PROF.Dr. DEMIR BAYKA AUTOMOTIVE ENGINEERING LABORATORY I

2. VARIOUS TRANSDUCERS AND SENSORS STRAIN DISPLACEMENT VELOCITY ACCELERATION AND VIBRATION FORCE TORQUE PRESSURE TEMPERATURE FLUID FLOW

3. MEASUREMENT OF STRAIN WHEN A FORCE (TENSILE, COMPRESSIVE OR RADIAL) IS APPLIED TO A MACHINE ELEMENT IN ONE DIRECTION ANY ONE OF THE DIMENSIONS (L) OF THE ELEMENT SLIGHTLY CHANGE BY ( d L )

4. e IS RELATED TO STRESS BY Hooke’s Law E = Modulus of elasticity (Young’s modulus)

5. D L F F

6. Let us take the logarithm of both sides

7. Differentiating the above equation ;

8. L DLDL DWDW W FF FOR A PRISMATIC ELEMENT

9. ALSO DEFINE : (Poisson’s Ratio)

10. If the temperature is held constant, the change in resistivity is approximately proportional to the strain.

11. F = GAGE FACTOR

16. MEASUREMENT OF DISPLACEMENT POTENTIOMETER L x Slider Vs Vo

20. CAPACITIVE TRANSDUCERS D x A W Permitivity for vacuum :

21. Rotary Capacitive Displacement Transducer Angle Sensor

22. MEASUREMENT OF VELOCITY Winding 1 DC Voltage Output Winding 2 South Pole North Pole Permanent Magnet Core

23. MEASUREMENT OF PRESSURE

24. Strain-Gage Based Pressure Cell

25. Capacitance-Based Pressure Cell Differential pressures as low as 0.01 inches of water can readily be measured. They are also quite responsive, since the distance the diaphragm is displaced is only a few microns.

26. Typical Piezoelectric Pressure Sensor When pressure, force or acceleration is applied to a quartz crystal, a charge is developed across the crystal that is proportional to the force applied

27. DIFFERENTIAL PRESSURE MEASUREMENT BY MANOMETERS U-TYPE İncluding the density of air

28. WELL TYPEINCLINED

29. MEASUREMENT OF FLUID FLOW 1.Collect certain amount of liquid at measured time interval 2.Disc, Rotary-Vnae, Impellar flowmeters Positive Displacement

30. PRESSURE DIFFERENCE METHODS

31. VENTURIMETER

32. ORIFICE METER

33. LAMINAR FLOWMETER

34. DISPLACEMENT FLOWMETERS

37. PITOT TUBE

38. MEASUREMENT OF TEMPERATURE THERMOCOUPLE

39. T1T1 T2T2 FOR A SINGLE WIRE WITH ENDS AT T 1 AND T 2 E 2 - E 1 = K ( T 2 - T 1 ) K = THE THERMO ELECTRIC SENSITIVITY

40. T1T1 T2T2 T3T3 T4T4 A B A

41. T1T1 T2T2 T3T3 T4T4 A B A 0

42. T1T1 T2T2 T 3 =0 T4T4 A B A MELTING ICE 0

43. T1T1 T2T2 T 3 =0 T4T4 A B A MELTING ICE DVDV T

44. RTD (RESISTANCE THERMOMETER)

45. R 1 =53 k W R1R1 R V ~100 W RXRX DVDV 18 v THE CURRENT IN THE ARMS OF THE WHEATSTONE BRIDGE IS ABOUT 0.5 Ma INITIALLY R v IS ADJUSTED SO THAT D V=0 AT A REFERENCE TEMPERATURE T O D V~i. D R X