1) Ultrasonic flow meters use ultrasonic waves to measure the velocity and volumetric flow of liquids and gases through pipes. They work by transmitting ultrasonic waves across the pipe and measuring the time it takes for the waves to travel in the direction of and against the flow. 2) There are two main types of ultrasonic flow meters: clamp-on and in-line. Clamp-on meters attach to the outside of pipes while in-line meters have transducers mounted directly inside the pipe. 3) Ultrasonic flow meters are non-invasive, have high accuracy around 1% of measured flow, require little maintenance as they have no moving parts, but have higher initial costs

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2. Saqib Mahmood
Sr: 341551
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Flow
Types of Flow
Ultrasonic Flow Meter
Types of Ultrasonic flow meter
Advantages / Disadvantages
Working Principles

4. Fluid such as gases Or liquids is in a motion in a specific Time
and Specific Place is called Flow .
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Units of Flow:
Gallons Per hour (GPH)
Litters per hour
Cubic meter Per second
Barrels per day

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The Motion of Fluid is smooth and
parallel
The Motion of Fluid is irregular and
Randomly .
Transitional flow is a mixture of laminar and
turbulent flow,

6. • The Types of Flow depends on Reynolds number
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Flow Types Reynolds number
LAMINAR FLOW Less than 2100
TURBULENT FLOW Greater than 4000
TRANSITIONAL FLOW 2100 to 4000
VDdVRN 
RN = Reynolds Number
V = velocity of Fluid
d = Density of Fluid
D = Diameter of Pipe
V = viscosity of Fluid

7. Mass Flow measure is
number of molecules in a
flowing Fluid .
Volumetric flow measure
spaces that those
molecules occupy.
We can measure Mass
flow when we haven't a
constant Temp. and
Pressure .
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8. Ultrasonic Flow Meter is
non-invasive flow meter.
Measure the Velocity of
Fluid by using the Ultrasonic
Waves. They use to measure
volumetric flow. Using An
Ultrasonic Transducer the
flow meter can measure the
average velocity along the
Path of Ultrasonic Waves.
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9. Ultrasonic is Sound wave with higher
frequencies upper the audible limit of Human
Hearing. Human can not hear this frequency.
Ultrasound devices operate with frequencies
from 20 kHz up to several gigahertz.
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11. There are Two Types of Ultrasonic Flow Meter.
 Clamp On Method
 In-Line Method
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Clamp on type
In Line type

13. There are Two Types of Working Principle of
Ultrasonic Flow meter.
 Doppler Effect
 Transit-Time Method
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14. Doppler type Flow meter
Work on Principle of
Doppler Effect .
This Flow Meter work on
Reflection of ultrasonic
wave. This Waves
Reflected by Reflective
Metrical such as Solid
Particles or Air Bubbles in
Flowing Fluid.
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15. Transmitting and Receiving
Element both are Mounted
on one side of Line.
Ultrasonic Waves
Transmitted into liquid. And
this Waves Reflected to
Receiver due to Reflective
Material.
And This Reflected waves is
proportional to Velocity of
Flowing Fluid. This Is A
Principle of Sound Pulse
Reflection.
• This Flow meter Only
Work when Liquid have
Solid Partials and Air
Bubbles.
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This Type of Flow Meter Work when
100ppm solid Particles are in Process
Fluid

17. Volumetric flow rate = K • VF • D
Where:
K = Constant
D = Inner diameter of the pipe
Vf = Flow Velocity
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18. 21 ttt 
In this Flow Meter, We
Measure Time Difference
of Transmitted
Ultrasound waves with
and against Flow
Direction.
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19. In This Type Two Transducer
are Mounted on Line.
One is Upstream and second
on Downstream of Fluid.
Both Transducer are
Transmitter and Receiver.
When Ultrasound Waves
Transmit Upstream to
Downstream They Move
Faster Rather then
Downstream to Upstream .
The Sound Wave Travel at 45
degree.
When Flow is not Flowing,
The Time Difference is Zero.
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20. Q = Calculated volumetric flow rate
k = Constant of proportionality
t1 = Time for sound pulse to travel Upstream to
Downstream
t2 = Time for sound Down Stream To Upstream
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}/{ 2121 TTTTKQ 

21. In W- Mount and V-Mount Method we use
Reflector that Reflect the ultrasound waves in
Direction of receiver. The Selection of Mounting is
based on pipe and Flow Characteristics .
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23. • Sonic Reflectors
• piezoelectric transducer (Piezoelectric and
Ceramic crystals)
FDT41- 46: 2 MHz
FDT- 47: 1 MHz
FDT- 48: 500 KHz
• Microprocessor
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Advantages Disadvantages
Accuracy is about 1% of
flow rate.
High initial cost
Long term reliability Temperature sensitive
Approved for custody
transfer
Dirt and fluid impact
performance and
measurement accuracy
No moving parts to
replace or lubricate. So
low maintenance cost
Sophisticated as compared
to Mechanical Flow meter.

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