The process of achieving accurate flow measurements has been occupying the thoughts of scientists and engineers for centuries. That’s because the precise measurement of a fluid’s flow is often a critical parameter for a wide range of industrial needs. The device of choice for this task is the flow meter. But what is a flow meter? Who invented them? And what types of flow meter are available today? In this article, we discuss this topic with Bürkert. As Fluid control experts, they explain all.
What is a flow meter?
Flow meters measure the mass or volume of a fluid (which can be a liquid or gas) in a line. Depending on the type of flow meter, people can either measure the totalised amount of fluid that has passed through the flow meter. Or the amount of fluid passing through it over a given period of time.
Flowmeters typically consist of three main bits. These are mostly combined for best performance:
- The primary flow measurement device.
- A transducer that senses fluid passing through this device.
- A transmitter that gives a flow reading from the transducer signal.
A brief history of flow meters
Humans have been using flow meters in some form or another for thousands of years, dating back to ancient civilisations. Their early flow measurement systems enabled them to channel river water into plumbing systems and predict their water supplies in advance.
It wasn’t until the eighteenth century that any new movements in fluid mechanics were made. These were thanks to the fluidic theories of Swiss experts Daniel Bernoulli and Leonhard Euhler. Arguably though, it was the nineteenth century that witnessed the greatest advancements in flow measurement. With the discoveries of Michael Faraday, Christian Doppler and Gaspard Coriolis. These all gave rise to flow meters inspired by their theories.
The principles of those great minds of the nineteenth century are still employed in various flow meters today. But further advancements in technology have also expanded the capabilities of modern flow meters. Take our FLOWave flow meter, for example. This innovative flow meter uses the same surface acoustic waves used to detect seismic activity to provide highly accurate, non-contact flow measurements.
Bürkert FLOWave flow meter
Surface acoustic wave (SAW) sensors like the Bürkert FLOWave flow meter use inter-digital transducers to create a physical wave and convert it back to an electrical signal. The FLOWave uses this technique to generate surface acoustic waves. These spread across the surface of its measurement tube and decouple into the fluid at a specific angle. The waves generate electrical signals when passing through the fluid once or several times in and against the flow direction. Any time differences that are detected are aligned to the flow.
Our patented SAW technology is specifically designed for the in-line flow measurement of fluids. The great benefit of which is that there are no sensor elements in the one-piece, stainless steel tube body. That equates to extremely accurate flow measurements, no pressure drops and no maintenance work. CIP/SIP capable and listening to sanitary regulations, the compact and lightweight FLOWave is ideal for applications demanding the highest hygiene standards.
Typical FLOWave applications involve hygiene and measuring the flow of water with low heat or electricity. As a result, this flow meter is well-suited to pharmaceutical applications. Such as in the production of pure media, and food and beverage applications, especially in the management of CIP and SIP processes. Essentially, wherever efficient media changes are required between batch processes to minimise wastage and maximise product take-home. This can ultimately save manufacturers a great deal of time and expense.
Flow meters for all applications
As well as the completely unique FLOWave, Bürkert also offers a comprehensive selection of flow meters to suit all manner of fluid control applications. The full range covers everything from differential pressure flow meters to electromagnetic flow meters and ultrasonic flow meters.
Oval gear flow meters
Oval gear flow meters employ positive displacement technology. This is to measure the volume of fluid passing through the flow meter. They do this by entrapping fluid in rotating parts to measure its flow. The more fluid that flows, the faster the rotating parts turn. The transmitter fundamentally determines the flow of fluid by processing the signal generated by the rotation. Oval gear flow meters delivers a high degree of accuracy and are primarily used for the flow metering of higher-viscosity fluids, such as oils, syrups and fuels.
Paddle wheel flow meters
Paddle wheel flow meters comprise a paddle wheel sensor, pipe fitting and a display. Our sensor is made up of a rotating impeller with magnets within. This is square to the flow and rotates when inserted into the fluid. As the magnets spin past the sensor, the flow meter generates a frequency and voltage signal proportional to the flow rate. The faster the flow, the higher the frequency and voltage output. In other words, due to the high accuracy and flow rates, paddle wheel flow meters are often used in water settings.
Thermal Mass Flow Meters
Thermal mass flow meters measure the mass flow rate of a liquid through a tube. It does this by either maintaining a probe at a constant temperature and measuring the needed energy to do so. Alternatively, by introducing heat into the flowing stream and measure any associated temperature change. Bürkert also supplies mass flow controllers that include a proportional control solenoid valve and control electronics to modulate flow. Thermal flow meters are used across a range of settings, from the recovery of gases, like methane, from coal mines to alcohol distillation and refining, to name but a few.
Bürkert’s proven track-record in fluid control
All flow meters come with their own unique pros and cons. Which means there is no one-size-fits-all flow meter. As such, your selection process should primarily focus on your individual needs. As opposed to the technology or indeed the relative cost of the flow meter. Our technical experts at Bürkert can provide practical advice and guidance to ensure you choose the right flow meter for your needs.
If you are purchasing a flow meter it’s important to find a manufacturer with a proven track-record in fluid control. We have more than 70 years at the forefront of the fluid control industry. Meaning that at Bürkert, we will do everything we can to find the technology that will perfectly match your requirements. Bürkert is one of the world’s leading manufacturers of measurement and control systems for liquids and gases. Whatever the application, we have a range of innovative flow meter products that deliver a precise, reliable and cost-effective solution.
More about Bürkert
Bürkert is a world-leading manufacturer of control and measuring systems for fluids and gases. For over 70 years, we have been devoting a lot of time and energy to liquids and gases. It is due to our experience in the field that our expanding global network, combined with the constant optimisation of our processes across all areas, we’ve been able to exchange experience directly and develop joint solutions more quickly and effectively. With a wide range of flow meters and other control instrumentation, they have the facility to adapt and develop existing technology to suit customer needs. Their products are suitable for a wide range of applications. These include renewables, food and beverage, pharmaceuticals, water treatment, gas handling and microfluidics. For more information, contact the Bürkert sales team on +44 (0)1285 648 720 or email firstname.lastname@example.org.