Flow Measurement & Control


Revolutionary flow measurement idea

May 2000 Flow Measurement & Control

Many instrumentation engineers are extremely weary when ultrasonic flow measurement is mentioned. However with the new helical sound guidance system, (patented by Siemens), engineers can now certainly rethink their opinions about ultrasonic flow measurement.

Operation principle

The propagation rate of ultrasonic waves in a medium depends upon the speed of sound in the medium and its flow velocity. Ultrasound reflectors in the flow tube produce a helical ultrasonic signal path along the flow tube – this is unlike the traditional method, where the signal is transmitted across the diameter of the pipe.

The two ultrasonic transducers alternatively transmit and receive ultrasonic signals. Propagation delays of the two ultrasonic signals will be different when a flow is present, with the delay being shorter when the signal travels with the flow, and longer when against the flow. The resulting difference is used to determine the flow velocity. This result is independent of the speed of sound in the medium, and therefore independent of the medium. It is also independent of the flow profile. This means that flow can be measured from turbulent flow through the transition region, and into laminar flow. Changes in temperature, density, viscosity and conductivity have no influence on the result. This means that almost all liquids, conductive and non-conductive, organic and inorganic and also almost all hydrocarbons can successfully be measured with this ultrasonic flow measurement principle. Since the measurement in the difference of propagation delay, the flow can be measured in both directions. The input of fluid density values would then allow masflow to be calculated.

There is no pressure drop across the flow tube, thanks to a design that makes use of a construction having no obstructions to the flow. Even the flow rates of slurries can be measured with success. A high degree of accuracy is obtainable, namely: 0,5% with a turndown of 25:1, and 1% with a turndown of 100:1. The alternate signal transmission permits bi-directional flow to be measured with the same degree of accuracy in both directions.



Credit(s)



Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

Flow measurement in mobile applications
ifm - South Africa Flow Measurement & Control
The SU Puresonic Mobile ultrasonic sensor from ifm is characterised by its displayless design and high temperature resistance. It is ideal for mobile applications and processes with permanent media temperatures of up to 120°C.

Read more...
Optimising water quality in a building cooling system
ifm - South Africa Flow Measurement & Control
A leading company in industrial water management has installed water treatment systems that not only optimise water quality but also help customers to improve their processes, thanks to the new insights and actions that can be generated based on the process data collected.

Read more...
Sustainable energy management
Siemens South Africa IT in Manufacturing
Utilising its innovative ONE approach technology, Siemens provides complete transparency on resource consumption and offers data-driven optimisation recommendations for sustainable energy management.

Read more...
New RFID communication module
Siemens South Africa Industrial Wireless
The new Siemens RFID communication module, Simatic RF128C enhances efficiency and flexibility, making it ideal for applications in the battery, electronics and semiconductor industries.

Read more...
Siemens Xcelerator empowers space-tech pioneer, Skyroot Aerospace
Siemens South Africa IT in Manufacturing
Siemens Digital Industries Software has announced that Skyroot Aerospace, a leading private space launch service company in India, has adopted Polarion software from the Siemens Xcelerator portfolio to digitally transform its software development processes and enhance efficiency as it aims to accelerate access to space for its customers worldwide.

Read more...
Operator panel simplifies control and boosts performance
Siemens South Africa SCADA/HMI
The Sinamics SDI Pro 14 cm operator panel is an innovative accessory for drive technology, providing efficient support for local engineering.

Read more...
Digital twin for Bavaria’s National Theatre
Siemens South Africa IT in Manufacturing
Siemens and the Bavarian State Opera are digitalising the acoustics in Bavaria’s National Theatre in Munich, Germany. The result is a digital twin that simulates sound effects, orchestral setups and venue configurations in a realistic 3D acoustic model so that musicians, the director and conductors can assess a concert hall’s acoustics even before the first rehearsal.

Read more...
New RFID communication module
Siemens South Africa Industrial Wireless
The new Siemens RFID communication module, Simatic RF128C enhances efficiency and flexibility, making it ideal for applications in the battery, electronics and semiconductor industries.

Read more...
Nidec adopts Siemens Teamcenter for electric motor development
Siemens South Africa News
Siemens Digital Industries Software has announced that Nidec Corporation, a Japanese manufacturer and distributor of electric motors, has adopted Teamcenter X software from the Siemens Xcelerator portfolio of industry software to achieve innovative motor development and supply to set new industry standards, including automotive.

Read more...
Next-generation road-legal race car.
Siemens South Africa IT in Manufacturing
Siemens Digital Industries Software has announced that Briggs Automotive Company (BAC) will move to the Siemens Xcelerator portfolio of industry software and use it to develop the next generation of its single-seater road-legal race car, Mono.

Read more...









While every effort has been made to ensure the accuracy of the information contained herein, the publisher and its agents cannot be held responsible for any errors contained, or any loss incurred as a result. Articles published do not necessarily reflect the views of the publishers. The editor reserves the right to alter or cut copy. Articles submitted are deemed to have been cleared for publication. Advertisements and company contact details are published as provided by the advertiser. Technews Publishing (Pty) Ltd cannot be held responsible for the accuracy or veracity of supplied material.




© Technews Publishing (Pty) Ltd | All Rights Reserved