MAJOR TYPES OF SENSORS AND THEIR ADVANTAGES/DISADVANTAGES

1. Safdy Systems Vortex Shedding

• Highly accurate
• Linear over very wide range
• Once-off factory calibration only
• No degradation over lifetime
• High initial purchase price
• Lower maintenance cost

2. Propeller Type

• Bearing slippage problem at low velocities
• Bearings degrade with time
• Susceptible to damage in harsh environment
• Low initial purchase price
• Needs regular calibration
• High maintenance cost

3. Resistance Type

• Dependant on air mass (chill factor)
• Compensation for humidity
• Compensate for air pressure
• Sensor must be kept clean