1. CRFS Study Force, Pressure, Flow & Volume

2. Force & Pressure Mechanical Strain Gauge Piezo-resistive Capacitive Inductive Optical

3. Mechanical Gauges Manometers Force summing devices

4. Strain Gauge Wire or foil which thins when stretched Resistance increases when stretched Usually used in pairs or groups of 4

5. Wheatstone Bridge Circuit Diaphragm flex stretches some & compresses others Increases sensitivity & linearity Full or half bridge

6. Piezo-resistive Semiconductor chip Resistance changes when flexed May include amplifiers

7. Capacitive Capacitance between diaphagm & 1 or 2 fixed plates Requires AC Limited by characteristics of gap contents

8. Inductive Inductance changes produced by metal diaphragm on 2 fixed coils Requires AC

9. Optical Light intensity varies with pressure

10. Pressure Absolute Gauge Differential

11. Flow Fleisch pneumotach Screen pneumotach Pitot tube Venturi / Orifice Rotating vane Mass Flow Ultrasonic Differentiation of volume

12. Reynold’s Number v s - mean fluid velocity, L - characteristic length (equal to diameter 2r if a cross- section is circular), μ - (absolute) dynamic fluid viscosity, ν - kinematic fluid viscosity: ν = μ / ρ, ρ - fluid density.

13. Fleisch pneumotach Resistive Linear

14. Screen pneumotach Resistive Linear

15. Pitot tube Bernoulli equation

16. Venturi / Orifice Bernoulli equation

17. Rotating vane Rotating air stream Low inertia follower Digital counter based

18. Mass Flow Thermal

19. Ultrasonic Doppler effect Accurate timing

20. Differentiation of volume Direct volume measurement Rate of change

21. Volume Watersealed Rolling seal Bellows Gasometer