Walter Flamma
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Working as an Industry Specialist for the Food, Pharma and Beverage market at Bronkhorst High-Tech, it’s needless to say I continuously monitor these markets, to find out where we can be a solution provider. One of the trends in the beverage market I have encountered is fast batch dosing of additives. Additive dosing is a typical application in which flow meters can be used. Let me explain where this applies in the beverage industry and why additive batch dosing has to go with high speed.

The trend of small batch production

Traditionally, many industries make large batches of one product (mass production), and the beverage industry is no exception for that matter. However, due to the development of wider product ranges and diversification, which many companies face, this traditional way of production lacks the flexibility and efficiency which is often required these days. Companies optimize their processes, to be more resilient and responsive to risks. Nowadays, the trend is to make batches depending on the actual demand.

There is a demand to be more flexible and cost efficient on many levels. In the beverage industry this involves easier changeover from one flavour product to another by minimum cleaning. To keep the additive dosing system separated from the main product stream (like water), most parts of the filling line will be kept untainted from additives. This will save time, cleaning liquid and therefore costs, when changing product.

The necessity of fast batch dosing

Most types of filling lines produce a high output. This demands an additive dosing system which provides fast batch dosing with high repeatability and accuracy. How can fast batch dosing be achieved properly? Important with fast batch dosing is the right amount of additive in the pre-defined dosing time. This amount is usually very small and the dosing time can sometimes be very demanding. A dosing time from several milliseconds up to a second is not unusual in the beverage industry. To accurately dose small amounts of additives at such speed can be a challenge and requires excellent flow control.

Bronkhorst solutions for fast batch dosing

We can offer several flow solutions to ensure the required accuracy and reproducibility for (fast) batch dosing. One way is by combining a Coriolis mass flow meter with a pump or suitable valve. With this system, fluids can be dosed in a controlled way into the production process.

Another option would be to use an ultrasonic volume flow meter instead. The hygienic designs of our ultrasonic volume flow meters and their capability for cleaning in place - CIP - make these flow meters a good match for the beverage industry.

Image description Figure 1. ES-FLOW Ultrasonic Volume Flow Meter

The advantage of both the Bronkhorst Coriolis flow meter and ultrasonic volume flow meter is that they are equipped with an integrated batch dosing functionality. This dosing technology allows batch dosing of small amounts of liquid additives with only a minimum of tolerance. The firmware is equipped with a “learning function” to correct even the smallest tolerances automatically (e.g. during start-up of the instrument or change of supply batches). The setup is customized to fulfill all requirements of the production; it can be integrated easily in already existing processes and production lines. Moreover, with this batch dosing functionality, quick and complex regulation with PLC or SCADA is not necessary anymore.

Image description Figure 2. Bronkhorst Dosing Technology scheme with mini CORI-FLOW mass flow meters

So whether you choose for Coriolis or Ultrasonic flow technology, our flow instruments can offer the solution for higher throughput, flexible machines, more rapid changeover and less product waste in the beverage industry. If you want to learn more on how Ultrasonic flow technology has proven itself to be a solution for additive dosing in candy manufacturing, please read the story of my colleague Erwin Broekman on how candy gets its own taste, texture and appearance.

Read more about additive dosing.

Kevin van Dijk
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At the beginning of a new year, it seems like a perfect time to look back at the many successful and interesting stories from last year’s Bronkhorst blog. On that account, I’ve made a selection of our most popular blogs published in 2018.

1. Real-time pressure and temperature compensation to optimize gas flow control

Kicking off our top list is the story about pressure insensitive gas mass flow controllers for low flow rates. These new mass flow controllers are equipped with an on-board pressure compensation functionality, so the instrument automatically compensates for inlet pressure variations. Our product manager for gas technologies, Vincent Hengeveld, explains the theory behind this functionality.

2. Turbulence effect in gas flow measurement

An explanation of the turbulence effect is a very popular topic. Our Customer Service Department often gets the question how the effects of turbulent flow can be minimized, as our thermal flow instruments behave best using a laminar flow. Read the blog of our Field Engineer, Allard Overmeen.

3. Miniaturization to the extreme: micro-Coriolis mass flow sensor

In this blog, Wouter Sparreboom shares the development of a MEMS-based Coriolis instrument, currently the lowest flow measuring Coriolis mass flow sensor in the world. MEMS is short for Micro Electro Mechanical System. To learn more about the principle of operation and the advantages of a MEMS sensor, please read the whole story.

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4. How to deal with vibrations using Coriolis mass flow meters?

This is a frequently asked question within the flow meter industry. A Coriolis mass flow meter is known as a very accurate instrument and it has many benefits compared to other measuring devices. However, it can be a real challenge using Coriolis instruments in low flow applications in the heavy industry where you may have to deal with all kinds of vibrations. Ferdinand Luimes, our product manager for liquid technologies, shares his experiences with you.

5. Mass flow control at the camping

In the midst of the winter, camping seems like far away. However, this topic remains popular during the cold days. Last summer we’ve explained all kind of applications you often encounter at a campsite, and the involvement of mass flow controllers. Experience the summer air for a brief moment, and read all about mass flow control and camping.

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Furthermore, I would like to thank our guest bloggers of this year, who were so generous spending their time in crafting an interesting blog contribution.

Guest bloggers [please tag these people in LinkedIn post if possible] Dr.Christian Monse (IPA), John S. Bulmer (University of Cambridge), Laure Pillier (PC2A Laboratory), Armand Bergsma (Pressure Control Solutions), Hans-Georg Frenzel (Hansa Industriemixer), and Lotte Pleging (Team FAST).

Surely you will enjoy reading these blog posts - if you haven't read them already. I wish you on behalf of our whole team great health, happiness and success in 2019.

Ron Tietge
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The Christmas holidays are coming! And just like in everyday life, Bronkhorst products are important for many applications being used during the Christmas season. Whether it’s decorations or dinner, it stands to reason that flow meters have been used in their production. In this blog I will briefly explain different Christmas related flow applications, and how flow measurement and control is involved.

Adding fragrances in candles

Most of us light up a few candles to create a bit of ambiance during Christmas. But besides that extra light you get, they often also have something else to offer. Candles can make a room smell like literally anything. Candle manufacturers work closely with fragrance companies to develop scented formulas that are not only pleasing, but will also burn safely and properly. The addition of fragrance to a candle should be carefully monitored to ensure the candle burns cleanly and safely. For dosing the fragrances in a candle, Bronkhorst CORI-FILL dosing technology would be a very good option to use.

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Mass flow control at your Christmas dinner

In most households, Christmas is usually celebrated with a sumptuous dinner. Such a dinner is partly made possible by mass flow meters. These instruments are used for the production of multiple foods and beverages, like:

Bronkhorst instruments are also often used for sealing, coating and sterilisation the packaging of such things as juices or dairy products. Want to learn more about mass flow measurement for the production of foods and beverages? Read all about the different applications in this industry.

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Dosing Teflon on baking trays

During Christmas dinner my family and I always enjoy using a table grill. But isn’t it frustrating when food sticks to your grill grates? Luckily, the baking tray of a table grill often has a Teflon coating to prevent food from sticking to it. Here mass flow control comes into the picture. Mass flow meters are used to evenly spray Teflon during the production of baking trays for optimal accuracy and consistency.

Christmas LED lights

Christmas and lighting are inextricably linked, for instance when it comes to the sparkling lights that light up your Christmas tree. All those tiny LED lights sparkling away have been produced with the help of a mass flow meter. After all, the working principle of LED is via a two-lead semiconductor light source. The semiconducting material used in LEDs is basically aluminium-gallium-arsenide (AlGaAs), which is accurately applied with mass flow meters. Different wavelengths involved in the process determine the various colours produced by the LEDs. Hence, light emitted by the device depends on the type of semiconductor material used.

The applications explained in this Christmas story are just a fraction of the possibilities that Bronkhorst instruments have to offer. Flow instruments can be used in numerous applications and industries. To find the right flow meter for your application, please visit

And finally, I would like to wish you all a very Merry Christmas and a Happy New Year!

Egbert van der Wouden
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Natural gas has been an important source of energy for domestic and industrial use worldwide. Recent trends in energy supply have led to changes in the composition of the supplied gas in many countries. Due to these changes, it becomes even more important to measure the composition of this gas. Especially in small-scale applications a need for in-line measurement technology was detected.

For instance, in the Netherlands in the 1950’s a large natural gas reservoir was discovered near Slochteren which supplied a steady and constant source for many decades. However, production from the Slochteren field is declining and will be stopped in 2030. Therefore, the gas grid has to be fed with gas from different sources.

Natural gas

What natural gas from all sources has in common is that it is composed of methane, usually 75…95%. The rest of the mix typically consists of higher alkanes, like ethane and propane and fractions of nitrogen and carbon dioxide. The exact composition depends on the source of the gas, so when a grid is supplied with a variety of gases the composition will change. Furthermore, other recent trends contribute to the fluctuations in composition.

Trends in gas compositions

Natural gas is very suitable to facilitate in the increasing use of renewable energies. Biogas produced from renewable energy sources in biogas plants can, after proper treatment, be fed into the grid. However, biogas composition will depend on the feedstock, which is not always constant in time.

  • For more information about adsorption processes used for purification of bio- or natural gas, read our blog about Biogas Purification Testing.

Another important trend is power to gas or P2G; here electricity, produced from renewable sources like solar or wind, is used to produce a gas as an energy carrier. This can be hydrogen produced with electrolysis, or synthetic methane by combining carbon dioxide and hydrogen produced from electrolysis.

A major factor in renewable energy is the mismatch between supply and demand. As you can imagine solar energy is only being produced during daytime. Transferring electrical energy into chemical energy by producing combustible gases and feeding this in the national grid can help to balance this mismatch by utilizing the large buffer capacity of the available gas networks. Recent research, by for instance Kiwa, has shown that the current gas grid in the Netherlands can handle several tens of percent of hydrogen with limited modifications.

All these factors are leading to increasing changes to the gas composition in the network. Composition and quality are strongly correlated; increasing amounts of inert gases, like nitrogen or carbon dioxide, reduce the amount of energy produced when burned, also known as the calorific value. The presence of hydrogen in natural gas can change flame characteristics, such as temperature and flame speed.

Measuring the composition

With changing chemical compositions it becomes increasingly important to measure calorific value and components. With only a single point of entry, one measurement sufficed to analyse the composition in the downstream network. In the present day grid, networks are more intertwined and have multiple points where gases are blended. At every point of entry, it is necessary to measure the composition, not only for quality control but also for fiscal purposes. In this way, the suppliers can make sure consumers receive the quality they need and are charged for the heating value of the gas rather than the volume they receive.

The current standard for determining gas quality is gas chromatography; this method is very accurate but also slow and expensive. Alternative methods like calorimetry are similarly expensive and have a large footprint, making it hard to implement in small-scale applications.

All these future trends lead to a need for measurement technology that can be used in-line and in small-scale applications. This requires sensors that are compact, cost-effective and preferably measure composition.

New solution for gas property measurement In collaboration with:

  • TNO (the Netherlands Organisation for Applied Scientific Research),
  • Venne Electronics (a Dutch supplier of electronic products) and
  • Dutch gas grid operators Alliander and Gasunie

Bronkhorst is developing a solution for gas property measurement that can be installed in many installations for a wide range of applications.


Probe sensor concept with protective cover removed.

The operational principle of the concept is based on the preferential absorption of gas components on coatings that are applied to interdigitated electrode structures. The absorption is proportional to component concentration and results in a change in electrical properties that can be detected as a variation in capacitance of the coating.


DIE sensor (sensor with a small silicon circuit) with interdigitated electrodes and coatings.

Currently, the concept is being tested in the natural gas network of the Netherlands in close collaboration with grid operators and project partners, Alliander and Gasunie.


Methane concentration in the Dutch national grid measured with the concept and gas chromatograph.

Based on the measured components detected at the different coatings, the calorific value can be calculated, based on the concentration of the measured components. In combination with the integrated pressure and temperature sensor, other key parameters for the characterization of natural gas like; Wobbe Index, Propane Equivalent or combustion air requirement can be determined.

By using these parameters as input for a control system, users can optimize their processes to increase efficiency, reduce pollutants, or manage load. For instance in processes such as:

  • Monitoring of gas quality in the national grid
  • Process control in the production of biogas/synthetic gas
  • Motor management for gas engines and burners

Would you like to learn more about odorization of natural gas? Have a look at our blog ‘How Mass Flow Controllers make our gas smell’

Ric Besseling
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In different kinds of applications like aging processes, validation testing and/or in research on plant growth, often a specified flow of moist air is needed to achieve specific ambient conditions in a test chamber. Nowadays, we have multiple solutions for these kinds of applications, one of them with the help of controlled evaporation and mixing systems. Let me explain what the benefits are of these systems in comparison with the more conventional bubbler systems.

How does a Bubbler System work?

Small concentrations of moist air can be created using a bubbler system. This conventional method requires optimal pressure and temperature control of the bubbler system. A complete bubbler level measurement system therefore consists of a source of compressed air, an air flow restrictor, sensing tube, and pressure controller. The latter converts the back pressure to provide output to a controller, which calculates the liquid level. The quality of the moist air fully depends on the theoretical calculation of the degree of saturation of the air flowing through the liquid and the accuracy of pressure and temperature control. With this conventional approach it is difficult to achieve a specific air moisture content.

Image description Figure 1. Set-up Conventional Bubbler System

Bronkhorst evaporation systems

In addition to this approach, Bronkhorst developed a CEM-system, based on Controlled Evaporation and Mixing, which can be used for moist air applications. This CEM-system is an innovative vapor delivery solution, based on a liquid flow controller (LIQUI-FLOW or mini CORI-FLOW), a gas flow controller and a temperature controlled mixing and evaporating device.

Compared to the more conventional bubbler system, a CEM-system offers a more direct approach. The method is very straightforward, and theoretically any concentration can be made in a matter of seconds with high accuracy and repeatability. Moreover, it’s possible to adjust a relative humidity between 5 and 95 percent.

Image description Figure 2. Set-up Bronkhorst CEM System

The moisture content is accurately controlled by the liquid flow controller and the amount of air flow can be adjusted by the gas flow controller. On top of the CEM a mixing valve allows for a correct atomization of water in the air flow. Because of the relatively low pressure ratio of the water mist in the air flow, the water can be evaporated at a low temperature in the spiralized heater tube at the outlet of the mixing valve.

CEM insights

The set-up of a CEM-system basically consists of:

  1. A Mass Flow Controller for gases for measurement and control of the carrier gas flow (e.g. EL-FLOW Select series).
  2. Mass Flow Meter for Liquids for measurement of the liquid source flow (e.g. LIQUI-FLOW series, mini CORI-FLOW series).
  3. Temperature controlled mixing and evaporating device (CEM) for control of the liquid source flow and mixing the liquid with the carrier gas flow resulting in total evaporation; complete with the Temperature Controlled Heat-Exchanger to add heat to the mixture; Basic Bronkhorst CEM-systems are available as a complete solution, including control electronics, offering total flexibility in realizing a vaporizing solution in virtually any situation.

Do you want to learn more about CEM technology? Visit the Bronkhorst Vapour Flow Control section on our website and read all about our different products and applications in vapour control.

Chris King
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Selecting the right flow meter is the key to success while selecting the wrong one means nothing but trouble. Flow meter technology has significantly increased the available choices for every kind of application. The right flow meter is essential for crucial data collection and the wrong one can lead to grief in the budget and costly lost production time. In this blog I will discuss some of the important elements that go into the decision-making process of a flow meter.

Price versus popularity, Most common criteria to select the flow meter

Beware of relying on two of the most common criteria that people tend to use in the selection process: cost and popularity. If you place price at the top of your criteria, it will be easy to get the wrong flow meter for the application or one that does not hold up physically or performance-wise. That bargain will quickly turn into a budget nightmare. If the measuring device and its ancillary equipment need frequent and expensive maintenance, what you saved on that flow meter will quickly dissipate. Moreover, a flow meter that has a higher initial investment can also make up for it by costing less to maintain and operate. Coriolis mass flow meters are more expensive in purchase initially than many other types of flow meters, but can save a great deal of money over time because they are easier to maintain, translating into less downtime.

Image description A Set-up of Coriolis Mass Flow Meters (mini CORI-FLOW)

While it is important to research what type of flow meter is most commonly used in your industry, just selecting what is popular can also lead to disaster. If the flow meter is not appropriate for the application, measurements can be under or over which means valuable material can be lost and revenue negatively impacted.

New flow technologies offer new solutions

Advances in technology can also put instruments on the market that may not be as well-known, but provide a better solution. For instance, in the past, inline ultrasound flow meters had to be re-calibrated when a new fluid was introduced and could not be used in applications where hygiene was important. Nowadays new ultrasonic flow meters have solved those concerns and opened up the use of inline ultrasound flow meters to those types of applications. A flow meter is a highly technical device that is influenced by lots of variables. We’ll breakout the most important ones, but realize that every application is unique.

Image description Ultrasonic volume flow meter (ES-FLOW)

Volume or Mass flow measurement

There are two basic measurements of fluids, volume and mass flow measurement, so a flow meter is either a volumetric flow meter or a mass flow meter. However, you can calculate volume from mass and mass from volume if you know the density and agreed upon variables. Whether a volumetric flow meter or mass flow meter is the best depends on the application, its components and the purpose of the measurement.

Flow meter categories

Some flow meters can be easily eliminated because they simply will not work with the application. For instance, electromagnetic flow meters will not work with hydrocarbons and require a conductive liquid to function. Many flow meters cannot measure gases or slurries. Listed below are some of the main flow meter categories paired with the fluid type the meters can handle.

  • Gas – Coriolis Mass, Thermal Mass, Ultrasonic, Variable Area, Variable Differential Pressure, Positive Displacement, Turbine
  • Liquid – Coriolis Mass, Thermal Mass, Ultrasonic, Variable Differential Pressure, Positive Displacement, Turbine, Electromagnetic
  • Slurry – Coriolis Mass, some subsets of Variable Differential Pressure, Electromagnetic, Ultrasonic
  • Vapour – Vortex, Ultrasonic, Diaphragm, Floating Element

Fluid properties

It is crucial to know the properties of the fluid being measured, below are some of the primary components:

  • Type of fluid – liquid, gas, slurry, vapour
  • Density
  • Viscosity
  • Temperature
  • Pressure
  • Condition of the fluid – foreign objects in it, suspended particles, air bubbles,
  • Other contaminants
  • Flow consistency – consistent or breaks, fill the pipe or partially fill or varies
  • Flow range – the minimum and maximum of the flow
  • Corrosive nature of the material – corrosive liquid or gas can deteriorate inline sensors

Physical properties

It is also important to know about the physical dynamics of the application site. Some of the physical properties of the site to consider are:

  • Configuration of the pipe before and after the flow meter and the length of straight pipe at the inlet and outlet of the flow meter.
  • The size of the pipe. Some flow meters have a poor performance with very small pipes and some cannot measure fluids in larger pipes
  • The material the pipe is made from
  • The surrounding environment and whether it is stable or variable
  • Will the flow meter work at a certain angle? This can seriously affect a flow meter’s performance Read in our previous blog why the choice of piping is important for thermal mass flow meters

Flow meter specifications

Last but not least, also the specifications itself have to be taken into consideration when selecting the right flow meter.

Accuracy – Naturally, an important factor of a flow meter is accuracy. To even suggest that accuracy is a variable seems ridiculous. Who would want an inaccurate meter? However, not all flow meters possess the same accuracy; some applications do not even require precision.

Image description Thermal mass flow meters for gas (EL-FLOW Prestige)

Repeatability – Repeatability means the number of times (%) you get the same results running the same test or measurement under the same conditions. Accuracy requires repeatability, but repeatability does not require accuracy. It just needs consistency. Therefore, it can be said that repeatability of a flow meter is often considered even more important than accuracy.

Turndown Ratio or Rangeability – This implies the range that a flow meter can accurately measure the fluid. Usually, it’s best to choose a flow meter with the greatest range available without compromising other components that are more critical.

Hygiene requirements – Flow meters for food, pharmaceuticals, and the medical industry especially demand sterile environments.

Cost – As stated above, this should include installation, maintenance and repairs over time. How much the meter costs to operate, like its electrical demands, can also increase the overall cost of the flow meter.

As you can see, there are a lot of variables to finding the right flow meter and the ones we have listed are only the basics. This does not even touch on the various options in different models. The best way to get the right meter is to get help with your search and team up with experts in the field. Experience matters.

It is important to get your information from people who know these complex and important devices. To let Bronkhorst help in the search for the right flow meter for your needs, please contact us.

• When you have selected the right flow meter, the next step is installing this instrument. Graham Todd gives some useful tips when installing a mass flow meter.