Ultrasonic flow measurement working principle

Ultrasonic flow meters works on the principle of transit-time differential method. Transit time differential is defined as the time difference between the time required for ultrasonic signal to cross the pipeline in one direction and the time taken by the signal in reverse direction. This measuring principle is based on a simple physical fact. Imagine two boats crossing a river diagonally, one with the flow and one against the flow. Naturally the boat that is travelling with the flow will reach the opposite side sooner and the boat that is travelling upstream which is against flow will reach later. Acoustic signals, like ultrasonic waves also behave in a same way.

By using ultrasonic sensors, the transit time of acoustic signals that travel upstream and downstream are measured. The difference in transit time is proportional to the mean flow velocity and is transformed into an output signal by the electronics.

The three measuring beams are generally used for making a three dimensional cross section of the medium that flows through the measuring tube. These measuring lines are positioned in such a way that the influence of the flow profile (laminar or turbulent) is largely reduced. Combined with the use of the latest signal processing techniques like Digital Signal Processing (DSP), a reliable measurement can be obtained. 

The flow velocity measurement of the 3-beam ultrasonic flow meter is based on measurement at three positions in the measuring tube. Two of the acoustic beams are located in symmetrical arrangement on the outside and the third beam is located in the centre of the measuring tube. Each individual acoustic path of measurement forms an angle Ø with the tube centreline. The ultrasonic waves travel from point A to point B at speed.

7

1

Also, from point B to point A at speed

2 

And the transit time taken from point A to B is given by the equation (distance/velocity), here distance is given by L length from point A to B.

3

And the transit time taken from point B to A is given by the equation,

4

 tAB and tBA are measured continuously. The mean flow velocity Vm of the product is calculated using the last two equations.

Mean velocity is calculate by the equation,

56

The popular ultra sonic flow meter is from Krohne UFM 3030.

8optisonic-3400-district-heating

Indian Penal Code

https://kishorekaruppaswamy.in/2019/02/26/indian-penal-code-ipc/

RTD

https://kishorekaruppaswamy.in/2019/02/27/temperature-transmitter-rtd/

Hook up diagram

https://kishorekaruppaswamy.in/2019/02/27/instrument-installation-hook-up-diagram/

Calibration of Siemens Sipart PS2

https://kishorekaruppaswamy.in/2019/02/27/calibration-of-siemens-sipart-ps2/

Calibration of Rosemount TT

https://kishorekaruppaswamy.in/2019/02/27/calibration-of-temperature-transmitter-zero-trimming/

Control valve sizing equation

https://kishorekaruppaswamy.in/2019/02/27/control-valve-sizing-equations/

Control valve leakage classification

https://kishorekaruppaswamy.in/2019/02/27/control-valve-leakage-classification/

Bently Nevada VMS continued

https://kishorekaruppaswamy.in/2019/02/27/bently-nevada-vms-continued/

Intrinsically safe barrier

https://kishorekaruppaswamy.in/2019/03/07/intrinsically-safe-barriers/

I/P converter

https://kishorekaruppaswamy.in/2019/03/07/i-p-conveter/

Lapping of a control valve

https://kishorekaruppaswamy.in/2019/03/07/lapping-of-a-control-valve/

Limit switch

https://kishorekaruppaswamy.in/2019/03/09/limit-switch/

Dampers

https://kishorekaruppaswamy.in/2019/03/21/dampers/

Hookup diagram continued

https://kishorekaruppaswamy.in/2019/06/06/hook-up-diagrams-continued/

Instrumentation related to a motor driven pump

https://kishorekaruppaswamy.in/2019/06/07/instrumentation-related-to-a-motor-driven-pump/

Flow transmitter DP type

https://kishorekaruppaswamy.in/2019/07/19/flow-transmitter-dp-type/

Typical foundation fieldbus wiring

https://kishorekaruppaswamy.in/2019/08/02/a-typical-foundation-field-bus-wiring-diagram/

Painting procedures

https://kishorekaruppaswamy.in/2019/09/14/painting-procedure/

Instrumentation cable design specification

https://kishorekaruppaswamy.in/2019/09/15/instrumentation-cable-design-specification/

Standard power supply requirements of instruments

https://kishorekaruppaswamy.in/2019/09/15/standard-power-supply-requirements-for-instrumentation-devices/

Acceptable ranges of Instruments

https://kishorekaruppaswamy.in/2019/09/15/acceptable-accuracy-ranges-of-instruments/

Instrumentation general design requirements part 1

https://kishorekaruppaswamy.in/2019/10/09/general-design-requirements-of-instrumentation-part-1/

Instrumentation general design requirements part 2

https://kishorekaruppaswamy.in/2019/10/09/general-design-requirements-of-instrumentation-part-2/

Instrumentation general design requirements part 3

https://kishorekaruppaswamy.in/2019/10/09/general-design-requirements-of-instrumentation-part-3/

Instrumentation general design requirements part 4

https://kishorekaruppaswamy.in/2019/10/09/general-design-requirements-of-instrumentation-part-4/

Instrumentation general design requirements part 5

https://kishorekaruppaswamy.in/2019/10/09/general-design-requirements-of-instrumentation-part-5/

AS-i

https://kishorekaruppaswamy.in/2020/02/22/as-i-actuator-sensor-interface-protocol/

Boiler

https://kishorekaruppaswamy.in/2020/03/03/boiler/

Thermistors

https://kishorekaruppaswamy.in/2020/04/05/thermistors/

Profibus

https://kishorekaruppaswamy.in/2020/04/05/profibus/

3 element control

https://kishorekaruppaswamy.in/2020/04/05/three-element-control-in-a-boiler/

Ultrasonic flow measurement

https://kishorekaruppaswamy.in/2020/04/05/ultrasonic-flow-measurement-working-principle/

Parameter setting of  E+H LT

https://kishorekaruppaswamy.in/2018/04/29/parameter-setting-of-eh-fmp51-gwr-lt/ Siemens LT parameter setting

https://kishorekaruppaswamy.in/2018/04/29/parameter-setting-of-siemens-probe-lu-ultra-sonic-level-transmitter/

Parameter setting of KTek LT

https://kishorekaruppaswamy.in/2018/04/29/parameter-setting-of-ktek-mt-5100-gwr-lt/ Analysis of Pump Vibration

https://kishorekaruppaswamy.in/2018/06/08/analysis-of-motor-pump-vibration/ HART Communication

https://kishorekaruppaswamy.in/2018/06/17/hart-communication/ Instrumentation tube fittings

https://kishorekaruppaswamy.in/2018/03/28/instrumentation-tube-fittings/

Radar LT non contact type

https://kishorekaruppaswamy.in/2018/03/19/radar-non-contact-level-transmitter-working-and-parameters/

Rosemount GWR parameter setting

https://kishorekaruppaswamy.in/2018/03/15/parameter-setting-of-rosemount-gwr-5300-series-lt/

Offset calculation GWR

https://kishorekaruppaswamy.in/2018/02/14/offset-calculation-for-a-guided-wave-radar-level-transmitter/

Temperature transmitter types

https://kishorekaruppaswamy.in/2018/02/13/temperature-transmitter-classification-tree/

Flow transmitter types

https://kishorekaruppaswamy.in/2018/02/13/flow-transmitter-classification-tree/

Level transmitter types

https://kishorekaruppaswamy.in/2018/02/13/level-transmitter-classification-tree/

Pressure  transmitter types

https://kishorekaruppaswamy.in/2018/02/13/pressure-transmitter-classification-tree/

Piping and Instrument diagram

https://kishorekaruppaswamy.in/2018/02/04/pid/

Smoke detector working

https://kishorekaruppaswamy.in/2018/02/02/smoke-detector-working-principle/

Conductivity transmitter working

https://kishorekaruppaswamy.in/2018/02/02/conductivity-transmitters/

Gas detector working

https://kishorekaruppaswamy.in/2018/02/01/gas-detector-working-point-gas-detector/

Flame detector working

https://kishorekaruppaswamy.in/2018/02/01/flame-detector-working-principle/

Units and conversion

https://kishorekaruppaswamy.in/2018/01/05/units-and-its-conversion/

Specific gravity

https://kishorekaruppaswamy.in/2018/01/05/specific-gravity-of-selected-liquidsgases-and-saturated-waterfor-different-temperatures/

Instrumentation Interview questions

https://kishorekaruppaswamy.in/2018/01/03/instrumentation-interview-questions/

Temperature transmitter calibration

https://kishorekaruppaswamy.in/2017/12/20/temperature-transmitter-calibration/

Pressure transmitter calibration

https://kishorekaruppaswamy.in/2017/12/19/pressure-transmitter-calibration/

Magnectostrictive LT calibration

https://kishorekaruppaswamy.in/2017/12/19/magnetostrictive-level-transmitter/

Hazardous area classification

https://kishorekaruppaswamy.in/2017/12/17/hazardous-area-classification/

Excel short keys

https://kishorekaruppaswamy.in/2017/12/16/excel-short-keys/

Digital electronics

https://kishorekaruppaswamy.in/2017/12/14/digital-electronics/

Thermocouple mV conversion chart

https://kishorekaruppaswamy.in/2017/12/14/thermocouple-temperature-mv-conversion-chart/

Foundation field bus

https://kishorekaruppaswamy.in/2017/11/20/foundation-fieldbus/

Rosemount 3051 series transmitter

https://kishorekaruppaswamy.in/2017/11/20/rosemount-3051-series-transmitters/

Hydrogen sulphide

https://kishorekaruppaswamy.in/2017/11/20/hydrogen-sulphide-h2s/

Root cause Analysis

https://kishorekaruppaswamy.in/2017/11/20/root-cause-analysis/

Shore Key Line up

https://kishorekaruppaswamy.in/2017/09/28/how-to-line-up-interface-level-transmitter/

pH Analyser

https://kishorekaruppaswamy.in/2017/09/27/ph-analyzer-working-principle-and-calibration/

Mathematic Formula

https://kishorekaruppaswamy.in/2017/09/24/important-mathematical-formulas/

India

https://kishorekaruppaswamy.in/2017/08/15/india/

Oil in Water Analyser

https://kishorekaruppaswamy.in/2017/08/13/oil-in-water-analyzer/

BSW Analyser

https://kishorekaruppaswamy.in/2017/08/13/bsw-analyzer/

Capacitive Level Transmitter

https://kishorekaruppaswamy.in/2017/08/12/capacitance-type-level-transmitter/

LRV and URV Level Transmitter

https://kishorekaruppaswamy.in/2017/08/11/lrv-and-urv-of-interface-level-transmitter/

Instrument Loop Diagram

https://kishorekaruppaswamy.in/2017/07/28/instrument-loop-diagrams/

Laser Level Transmitter

https://kishorekaruppaswamy.in/2017/05/20/laser-level-transmitters/

Turbine Flow Transmitter

https://kishorekaruppaswamy.in/2017/05/20/turbine-flow-meter/

Zero Suppression and Elevation

https://kishorekaruppaswamy.in/2017/05/18/zero-suppression-and-elevation/

Bently Nevada 3500 VMS

https://kishorekaruppaswamy.in/2017/04/08/bently-nevada-3500-vms/

Control Valve Servicing

https://kishorekaruppaswamy.in/2017/04/08/smp-of-a-control-valve/

Safety Integrity Level

https://kishorekaruppaswamy.in/2017/02/23/safety-integrity-level-sil/

Instrumentation Working Principle

https://kishorekaruppaswamy.in/2017/02/22/instrumentation-working-principle-continued/

Instrumentation Gland Sizes

https://kishorekaruppaswamy.in/2017/02/15/instrument-gland-sizes/

LRV and URV of DP level transmitter

https://kishorekaruppaswamy.in/2017/01/02/lrv-and-urv-determination-for-d-p-type-level-transmitter/

Instrumentation working principle continued

https://kishorekaruppaswamy.in/2017/01/02/instrumenation-working-principle/

Level measurement using Pressure gauge

https://kishorekaruppaswamy.in/2016/06/10/level-measurement-using-pressure-gauge/

Tips and tricks in field Instrumentation

https://kishorekaruppaswamy.in/2016/04/18/tips-and-tricks-in-field-instrumentation/

Data Communication Protocol

https://kishorekaruppaswamy.in/2016/03/10/data-communication-protocols/

Pressure Unit Conversion

https://kishorekaruppaswamy.in/2016/02/19/pressure-unit-conversion/

Calibration of  GWR level transmitter

https://kishorekaruppaswamy.in/2016/02/19/calibrationtheory-and-initialization-of-gwr-level-transmitter-rosemount-5300-and-ktek-5100/

Control Valves

https://kishorekaruppaswamy.in/2016/02/18/control-valves/

ERS Level transmitter Parameters

https://kishorekaruppaswamy.in/2016/02/18/calibration-and-initialization-of-electronic-remote-seal-level-transmitter-rosemount-3051ers/

Calibration of wet leg tube Level transmitter

https://kishorekaruppaswamy.in/2016/01/16/calibration-and-initialization-of-wet-leg-impulse-tube-rosemount-3051cd-series-lt/

Calibration of capillary type Level transmitter

https://kishorekaruppaswamy.in/2016/01/15/calibration-and-initialization-of-rosemount-3051cd-capillary-type-level-transmitter/

mV conversion chart

https://kishorekaruppaswamy.in/2015/02/27/942/

Gulf JOB

https://kishorekaruppaswamy.in/2013/09/18/contact-details-for-gulf-jobs/

Reynolds Number

https://kishorekaruppaswamy.in/2012/11/28/reynolds-number/

Calibration of displacer type LT

https://kishorekaruppaswamy.in/2012/11/16/calibration-procedure-of-displacer-type-level-transmitter/

My profile

https://kishorekaruppaswamy.in/2012/06/20/click-here-then-photo-and-view-profile/

Chemical hazard pictogram

https://kishorekaruppaswamy.in/2012/04/04/chemical-hazard-pictograms/

RTD conversion chart

https://kishorekaruppaswamy.in/2012/02/17/calibration-of-dp-type-transmitter-with-actual-pressure/

Ingress Protection

https://kishorekaruppaswamy.in/2012/01/18/ingress-protection/

To know more about Instrumentation and Control,

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or

https://kishorekaruppaswamy.in/2012/09/30/basic-instrumentation-and-calibration/