How to measure Flow?

Flow Strainers, Impellers, Magnetic sensing pickups. 

Turbine Meter

• good for telemetry
• errors may be caused 'coz of excessive frictional torque.

Electromagnetic flowmeter

• suitable for slurry, sludges etc
• Adv: size adaptability,No pressure drop
• Disad: for heavy slurry, high operating cost.

Hot Wire Anemometers

• more flow > more cooling
• voltage variation
• measured by POT

Using Thermister

• can measure velocity of air

Ultrasonic flow meter

• used mainly for liquid
• useful for bidec tional flow
• Adv:linear relationship
• Adv:insensitive to variation in viscocity, density and temp
• Disadv: complexity
• Disadv: relative high cost