Wellcome

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Wellcome Bienvenue Willkommen Bienvenido ?????
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The Transit Time Clamp-on Flow Metering Technique
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Introduction

• Principle of operation.
• Modes of operation.
• Installation guidelines.

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Principle of operation

• The general principle of time of flight flow
  measurement.
• The phase measurement system.
• Modes of operation

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The general principle of time of flight flow
measurement.
 
Approximate relationship between fluid velocity
and measured time. Does not include clamp on
transducer delays.
Vf Flow velocity l Distance between
transducers Cf Path length between transducer
faces t Transit-time downstream Kn Profile
correction factor ? Propagation angle
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Typical sound path for a clamp on ultrasonic meter
Pipe cut through side view
Transducer
Steel
Plastic
Line represents path of sound wave
Water
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The phase measurement system
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?
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Modes of operation

• Reflex mounting
• ease of setup
• good results over a
• broad range of
• applications

• Diagonal mounting
• extends the readable
• pipe diameter for given
• sensors
• better for high flows
• better with turbulent
• applications

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Modes of operation

• Double reflex mounting
• ease of setup
• useful for smaller pipe
• diameters
• good on low flow rates

• Triple reflex mounting
• ease of setup
• useful for smaller pipe
• diameters
• good on low flow rates

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Installation guidelines

• Transducer positioning.
• Flow profiles

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Ultrasonic flow meter axial and radial sensor
location
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Summary

• Principle of operation.
• Modes of operation.
• Installation guidelines.