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.
Driving digital transformation in the truck industry Siemens South Africa
IT in Manufacturing
Tatra Trucks, a leading truck manufacturer in Czechia, has adopted the Siemens Xcelerator portfolio of industry software including Teamcenter software for product lifecycle management and the Mendix low code platform to help increase production volume and strengthen its ability to manufacture vehicles that meet specific customer requirements.
Read more...Enhancing cyber security for industrial drives Siemens South Africa
IT in Manufacturing
The growing connection between production networks and office networks as part of IT/OT integration and the utilisation of IoT have many benefits for industrial companies. At the same time, they also increase the risk of cyber threats. Siemens ensures that your know-how and plants are protected at all times.
Read more...Uncompromising flow rate measurement Burkert South Africa
Flow Measurement & Control
Bürkert’s FLOWave is a hygienic and safe flow measurement solution with many benefits for pharmaceutical or food production processes.
Read more...Electromagnetic flow measurement Siemens South Africa
Flow Measurement & Control
The SITRANS FM electromagnetic flowmeters from Siemens deliver high-precision volume measurement of electrically conductive liquid applications – from water, wastewater and irrigation to hygienic processes and even mining slurries with magnetic particles.
Read more...New generative AI-powered maintenance offering Siemens South Africa
IT in Manufacturing
The Siemens Industrial Copilot is revolutionising industry by enabling customers to leverage generative AI across the entire value chain – from design and planning to engineering, operations and services.
Read more...ABB unveils next generation of electromagnetic flowmeters ABB South Africa
Flow Measurement & Control
ABB has launched its latest generation of electromagnetic flowmeters, bringing unmatched accuracy, connectivity and flexibility to industrial and utility applications.
Read more...Precision measurement for ultra-pure water systems
Flow Measurement & Control
[Sponsored] Ultra-pure water (UPW) is essential in industries where even minor contaminants can impact product quality and process integrity. Anton Paar’s L-Cor Coriolis mass flowmeters provide a highly accurate and hygienic solution by directly measuring the mass of the liquid using the Coriolis effect, ensuring a high level of cleanliness.
printer friendly version