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1Motion and dimensional measurement
By
Aj. Somchai Triratanajaru M.Eng. KMUTT,
B.EngKMITL
Term 1/2553
2LECTURE OUTLINE
1. Standards and Calibration 2. Relative Displacement: translational and
rotational 3. Relative Velocity: translational and rotational 4. Relative Acceleration Measurements 5. Seismic-(Absolute-)Displacement Pickups 6. Seismic-(Absolute-)Velocity Pickups 7. Calibration of Vibration Pickups 8. Jerk Pickups 9. Angular-Displacement Sensors
3LECTURE OUTLINE
10. Coordinate-Measuring Machines 11. Surface-Finish Measurement 12. Machine Vision 13. The Global-Positioning
*Major part of this presentation are from Measurement Systems, Ernest O. Doebelin
41.Standards and calibration
Fundamental standard.Length standards-> wavelength of kypton-86.(fundamental standard, ultimate standard)Atomic clock-> atomic resonators cesium-133 Calibration.For application standards (engineeringapplicable) will be inform in each section.
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Relative displacement : Translational and Rotational
Calibration-Static calibration via micrometers 0.01 mm
gage blocks 12 micro-mlaser interferometer 0.6 nm
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Transducer applications of displacement (basic for the others variable)
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Resistive Potentiometers (single-turn, multi-turn, linear and rotating translation)
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Potentiometer loading effect (Linearity, power loss)
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Construction of wire-wound resistance (resolution)
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Conductive-plastic potentiometer.
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Magneto-resistive displacement transducer.
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Un-bonded strain gage (metal)
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Metal wire under extension force
A A-dA
L L+dL
F F
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Resistance Strain Gage.
R=L/A -> dR=(A(dL+Ld)- LdA)/A2 (a)V=AL -> dV=AdL + LdA (b)Also, (from static engineering)dV = L(1+)A(1- )2 AL (c):unit strain, : Poissons ratio. And, (from numerical approximation) when is small, (1- )2 -> 1- 2, (b)=(c)dV = AL(1-2) = AdL + LdA
-2AdL= LdA
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Resistance Strain Gage..
dR=(AdL+LAd + 2AdL)/A2
dR=(dL(1+2))/A + (Ld)/AdR/R = (dL/L)(1+2) + d/
Gage factor or GF -> (dR/R)/(dL/L)= 1 + 2 + (d/)/(dL/L)(a:) (b:) (c:)
a: R change due to length changeb: R change due to area changec: R change due to piezo-resistance effect(GF is + with metal with semi-conductor)
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Resistance Strain Gage
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Resistance Strain Gage.
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Resistance Strain Gage..
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Foil strain gages
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Foil strain gages..
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Foil strain gages
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Strain-gage rosettes
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SG Signal conditioning
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Strain-gage temperature compensation
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Stability of SG
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SG displacement transducers and extensometer
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Extensometer analysis
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Weld able strain gage
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Differential Transformers
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Methods for Null Reduction
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Demodulation & Filtering.
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Demodulation & Filtering..
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Demodulation & Filtering
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LVDT: Signal Conditioning
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Industrial type LVDT
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LVDT Application
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Application..
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Application
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Application.
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Inside LVDT
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Inside LVDT..
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Inside LVDT
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Real LVDT
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Small LVDT
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Integrated electronics
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On-board LVDT
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AC Servomechanism
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Synchos
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Resolver and digital converter
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Variable-inductance pickup
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Variable inductance accelerometer
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Micro-Syn
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Eddy current non-contact transducers
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Target-Material Effect on Eddy-Current Transducer
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Capacitance Pickups
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Frequency Response of Capacitive Sensor
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Differential-Capacitor Pressure Pickup
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Feedback-Type Capacitive Pickup
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Feedback-Type Capacitive Pickup..
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Capacitive Pickup: Signal Processing
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Capacitive Pickup: Signal Processing..
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Piezoelectric Transducer
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Piezoelectric Transducer
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Piezoelectric Transducer..
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Three-Component Piezoelectric Force Transducer
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Fiber-Optic Displacement Transducer
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Laser Dimensional Gauge
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Michelson Interferometer
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Self-Scanning Diode Arrays and Cameras
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Homographic
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Homographic..
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Nozzle Flapper
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Nozzle Flapper..
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Translational and Rotary Encoders
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Schematic diagram
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Translational and Rotary Encoders..
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Disk image form
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Translational and Rotary Encoders..
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Translational and Rotary Encoders
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Output wave form of incremental encoder
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Linear encoder (open type)
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Linear encoder (enclosure type)
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Resolution of Displacement Sensors
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Ultrasonic Displacement Transducer
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Velocity-Calibration Setup
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Average Velocity Measurement from x/t : Magnetic Pickup
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Average Velocity Measurement from x/t : Photodetectors
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Average Velocity Measurement from x/t : Hall-Effect Proximity Pickup
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Fly-ball Angular-Velocity Sensor
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Moving-Coil and Moving-Magnet Velocity Pickup
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Moving-Coil and Moving-Magnet Velocity Pickup..
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Tachometer Generators
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Drag-Cup Velocity Pickup
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Translational and Rotational Seismic Pickups
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Coordinate-Measuring Machines
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Touch Probe
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Surface-Finish Measurement
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Optical Surface-Finish Measurement
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Machine Vision: Applications and Features
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Light sheet Applications
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Integration of Machine Vision into Manufacturing System
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Further reading and more exercises
Text.Process control Instrumentationtechnology
Curtis D. Johson