22. CONTINUOUS SENSORS 435

22.1 INDUSTRIAL SENSORS 436

22.1.1 Angular Displacement 436

Potentiometers 436

22.1.2 Encoders 437

Tachometers 440

22.1.3 Linear Position 440

Potentiometers 440

Linear Variable Differential Transformers (LVDT) 441

Moire Fringes 442

Accelerometers 443

22.1.4 Forces and Moments 445

Strain Gages 445

Piezoelectric 448

22.1.5 Liquids and Gases 449

Pressure 450

Venturi Valves 450

Coriolis Flow Meter 451

Magnetic Flow Meter 451

Ultrasonic Flow Meter 452

Vortex Flow Meter 452

Positive Displacement Meters 452

Pitot Tubes 452

22.1.6 Temperature 453

Resistive Temperature Detectors (RTDs) 453

Thermocouples 453

Thermistors 455

Other Sensors 456

22.1.7 Light 456

Light Dependant Resistors (LDR) 456

22.1.8 Chemical 457

pH 457

Conductivity 457

22.1.9 Others 457

22.2 INPUT ISSUES 457
22.3 SENSOR GLOSSARY 460
22.4 SUMMARY 461

22.4.1 References 461

22.5 PRACTICE PROBLEMS 461
22.6 ASSIGNMENT PROBLEMS 462
22.1 PRACTICE PROBLEM SOLUTIONS 463