Flow sensor or flowmeter?

flow sensor

Flow sensor or flowmeter, that’s the question 😉

To be honest, when we would be having a conversation about your application, it doesn’t matter wether the needed instrument is referred to as flowmeter or flow sensor. We will both know what we mean and come to the right conclusion.

A different situation is the moment that an engineer starts searching the internet for a flow sensor. Chances are high that the search result returns a sensor which has no proper measuring capability. A disappointing testresult is to be expected.

When to choose for a flow sensor?

Flow verification

A flow sensor will return a signal when flow is detected. So if you look for a flow-verification, a sensor is sufficient. You may have already a signal that the pump is running, but due to numerous aspects in the piping system, it is well possible that the intended flow is not happening. A simple sensor will provide certainty!

High-Low flowrate

In your system there might be situations where a high or a low flowrate occurs, a sensor might be ccurate enough to properly determine which of the stages is actual. Again a good sensor-application.

When is a flowmeter the better option?

Input for a controlled flow

In equipment there are often liquid cooling circuits in which a nominal flowrate is designed. In process-circumstances the actual flowrate may differ from the nominal value.
The actual flowrate is converted in real-time to an analogue value (often 4-20 mA range).
This signal acts as a reference for adjusting the pump.
The result is a flowrate that is continuously at the designed value, providing maximal thermal stability to the equipment.
MIB’s Flowmax 44i is a commonly used instrument in piping up to Dn25 m.
Higher flowrates are handled by Flowmax 54i.

Qualification of a pump

Imagine your engineers designed a new setup which will be the basis of all your machines in the future.
Do you trust the specs on paper, or would a validation make sense? In most industries qualification and validation are mandatory.
A test-bench with an accurate flowmeter is part of that.

Volumetric / Batch-control

In applications where a certain volume needs to be dispensed or transported, a flowmeter is the right instrument to measure the volume which has passed.
Flowmax has the option to define the batch-volume and when this amount is measured, a digital output signal informs the system that valves can be shut and pumps turned off.

Volumetric control for financial transactions

When purchasing fuel, the dispenser registers the amount of dispensed.
The measured volume is used to initiate the financial transaction.
The instrument to use here is not a flowensor and not a normal flowmeter, it requires MID-approval.
Flowmeister is happy to advise you on this topic!
Sorry we can’t fill it in with the range of Flowmax instruments.

What’s your application? Get advised and receive a quote !

Your instrument has been tested, which is certified with the delivery. Optionally, a 3- or 8-point calibration-certificate can be ordered to prove the exact accuracy.

Before you submit:

you may trust an honest advise. If FlowMax is not your best possible solution, I will explain you why that is.

Flowmax products

Previous Image
Next Image

info heading

info content

Trust by design

When asked what is the most important property of flow measurement, almost every customer answers “ACCURACY”.
Understandable, you would rather not invest in an inaccurate instrument to control your pocess.

When the conversation continues, very often it appears that the automated production system is not too dependent on accuracy of the flowmeasurement itself.
The product-quality is more influenced by process-aspects that cause wrong readings coming from the meter.
In certain circumstances, it appears that the readings cannot be trusted.
The design of Flowmax ultrasonic flowmeters is made to be trusted.

Reliability is the key …

Some physical examples of improved reliability:
– An open bore without obstacles is never causing disturbances, cavitation
– No moving or rotating parts in the liquid which may wear out or get stuck
– Moving or rotating parts may release particles in the liquid
– No gaps, dead space or seals to affect product quality or leakage
– Air bubble detection immediately warns for detected bubbles
– Robust measuring tube, physically stable measuring unit
– Solid sensor mounting, not sensitive to environmental vibrations

All reliability features apply equally to Industrial and Single Use versions!

… and Accuracy matters

Of course accuracy matters.
Third to Reliability and Speed, the measuring accuracy is one of the selling features of Flowmax ultrasonic flowmeters!
Our biggest advantage is the fact that the calibrated measuring tube is inserted into your flowpath.
Calibration data is stored in the measuring tube.
This simple fact ensures that the performance in your system is comparable to the performance in the manufacturers’ calibration setup!
What else would you need?

What makes your application special?

Your instrument has been tested, which is certified with the delivery. Optionally, a 3- or 8-point calibration-certificate can be ordered to prove the exact accuracy.

Before you submit:

you may trust an honest advise. If FlowMax is not your best possible solution, I will explain you why that is.

Dosing of glue

dosing glue

Glue is known to stick materials together.
Instrumentation is known to be sensitive to contamination.
Could the two be a succesful match?

Don’t be afraid to get stuck

Instrumentation is often comparable to a Swiss watch, very ingeniously made, accurate and beautiful, but to be treated with care.
Imagine glue entering the heart of your Swiss watch….. the time-reading would never be accurate again!

What matters most, the top 3

In industrial processes we can meet applications where glue needs to be dosed in order to monitor and control the total process.
In addition to the sticky-challenge, there is also chemical resistance and a highly irregular flowrate to be put into the equasion.

Seven ways to be certain

Sofar we’ve only seen properties where the ultrasonic principle is a comfortable choice.
1) With the open-bore design and zero internal moving parts or gaps, the risk of clogging and getting stuck is completely absent.
2) The smooth surface of the plastic measuring tube makes the glue pass easily.
3) With a range of available materials, it’s nearly always possible to use a material which is similar -or better- to your piping and / or pump internals.
4) intermittant flow -typical to dosing cycles- is no big deal for the fast ultrasonic sensors. With 250 measurements per second you may trust that flow-fluctuations are captured properly.
5) the high turn-down factor of 60:1 allows for a comfortable rangeability, ensuring that lowest flow is measured, whilst high peaks are still within measurement-range of the instrument.

And if applicable or required:
7) With Flowmax 242i we have Single Use versions available.
It may be a safe feeling to have a low-cost replacement of only the wetted part on the shelf.

Did I miss something?

Yes you did, I’m sorry.
6a) bore ranges from Dn 5 up to Dn50 allow a very wide range of applications. starting at one liter per hour.
6b) with remote electronics, the connected measuring tube carries its own calibration data and can be swapped with other bore-sizes instantly. How flexible!

Is this your problem?

Maybe it is, if so, I will be glad to help you out!
Just let me know what it is about and we’ll be in touch soon.

Your instrument has been tested, which is certified with the delivery. Optionally, a 3- or 8-point calibration-certificate can be ordered to prove the exact accuracy.

Before you submit:

you may trust an honest advise. If FlowMax is not your best possible solution, I will explain you why that is.

Repeatability vs reproducibility


A short blog about terminology which is often used when flowmeter specifications are discussed.

The quality of the instrument is easily verified by doing a number of repeated measurements and comparing the measured values.
A robust measurement concept will prove the multiple readings to be close to each other, there is little to no variance.
The flowmeter then has a high repeatability, which is a positive aspect.

An ultrasonic flowmeter has no moving parts which inherently adds to the repeatability when compared to a turbine-meter where overspin and start-stop behaviour leads to variances.

What about reproducibility

Sometimes the term reproducibility is mentioned, this is a correct word, with a very different meaning than repeatability.
Reproducibilty indicates how succesful a different person can obtain similar results from the same flowmeter.
Again here a turbine-meter is more sensitive to the piping and orientation which reduces the chance that readings will be exactly the same in a random setup.

The mix-up of the two terms is often heard in Dutch-speeking countries, which is not a coindence.
The Dutch translation of repeatability is reproduceerbaarheid, often mixed up with reproducibility.

Is repeatability relevant for flowmeister

Flowmeister uses repeatability the way it was intended.
The open bore instrument with no moving parts proves repeatable, time after time after time.


Our single use instrument-range (Flowmax 242i) shares all design features which make the industrial instruments reliable and repeatable.
This includes a full calibration, ensuring a trusted operation, no matter if it is for hours, days or years!

Reproducibility matters as well.

Our different customers all experience good performance of the flowmeter.
Either in chemical, semi-conductor or OEM-industry, the results are good.
This is an example of reproducibilty.

More about repeatability and reproducibility can be read here.

React to this post

I hope the above gives clarification between two terms.
Clarification and better understanding lead to less mix-up in your daily flow-business.
Let me know if further questions or remarks pop up.

… at the speed of sound!

flowmeter calibration

Multi-parameters reading from your liquid

How direct and indirectly measured parameters tell what’s inside your tubes

Hygienic manufacturing focuses on safety and reliability.
Cleanliness is one of the external aspects to affect product quality.
Product-sampling is often performed to verift product-quality.
To reduce waste, the challenge is to quickly and accurately identify different fluids in the process pipework.
Reading multiple properties of the liquid can now be achieved while measuring the flowrate.

Cleaning in Place to prevent contamination

Flowmeters can come in all shapes and sizes and finding the most appropriate design for a particular application can be difficult.
However, for hygienic applications, models with open bore and no dead space inside will considerably shorten the start-up if your line.
The ease of cleaning and ability to withstand Clean in Place (CIP) procedures,saves time and adds value.

Cleaning processes have a significant impact on many aspects of the design when it comes to selecting the most suitable components.
CIP uses both heat and chemicals to remove scale, bacteria, and debris from process vessels and pipework, including your flowmeter.

Modern production facilities will be used to produce a range of products and manufacturers are faced with the challenge of ensuring that one product is not contaminated with another. In many cases this process is completed using a timer, so, when the first production run has finished, the lines and vessels are flushed and cleaned, with the output going to the drain.

The duration of the cleaning flush cycle (in the above example from 9..19) is a fixed period which guarantees that none of the previous product remains in the system.
A next batch of product then starts to flow, and this also continues to drain for a further period, until it is certain that none of the water or cleaning solutions are in the line.

Reduce waste, improve productivity

To be sure there is no contamination, safety factors are built-in to these processes, which inevitably means that cleaning fluid – and valuable product- is sent to the drain.
By using a method of accurately identifying the fluids and their flow volume in the pipework, considerable cost savings as well as improving productivity for manufacturers can be achieved.

How can a flowmeter recognize liquids?

An ultrasonic flowmeter uses acoustic waves to obtain a direct measurement of flow.
Flowmax measures the time that an acoustic signal needs to travel through the liquid.
The instrument also measures temperature.
As a result of the measuring process we know two more parameters: the actual speed of sound through the liquid and the acoustic transmission factor.
These directly and indirectly acquired parameters can be analyzed to provide a real-time indication of the contents of the pipework.
When these parameters are logged, an operator can verify and proove at all times which liquids have been running through the meter, at which temperatures and for how long.

Each liquid has its speed of sound curve.

Sanitairy design

For hygienic applications, the open bore housing without gaps or dead space is ideal.
The smooth wall pipe design means there is no direct contact of any sensor components with the fluid.
The body DN-size can be manufactured to the same diameter as the rest of the pipeline.
In terms of hygiene, cleaning and flow-conditions, there is nearly no difference to any other piece of straight pipe.

Reducing costs

Process-operators have found that they not only save product that would have otherwise been wasted, but the additional information saves a considerable amount of time. By reducing the total change-over-time, the productivity of the process greatly improves.
Each reduction in the volume of fluids being sent to the drain also delivers savings in water treatment costs.

Four Flowmax 400i with #Speedmax speed of sound output

It’s not magic

Let’s remember that the flowmeter got installed to measure flow.
All other information that it retrieves is a nice extra.
The direct readings are valuable, accurate and true (flow, temperature, actual speed of sound, bubbles yes/no).
Conclusions drawn towards density and viscosity may be close to accurate, but if absolute certainty on these properties is required, Flowmeister advises to use a Coriolis-meter.
(When cost and sensitivity matter, the Flowmax ultrasonic flowmeter portfolio is worth investigating.)

Find out more or request a test

Flowmeister can test your liquids and show how distinct the separate liquids behave inside the Flowmax device.
That remains the best way to get understanding of the reliability of liquid-recognition.
Feel free to leave your comment, request or questions in the form below.

Your instrument has been tested, which is certified with the delivery. Optionally, a 3- or 8-point calibration-certificate can be ordered to prove the exact accuracy.

Before you submit:

you may trust an honest advise. If FlowMax is not your best possible solution, I will explain you why that is.

This blog was inspired on Flowmax customer stories, a Bürkert-post and MIB GmbH test-results.

Flow-control main reason to measure flow


Only a few processes get better by flow-measurement alone. These are often processes where a delivered volume of liquid needs to be invoiced, like filling up your car at the gas-station.
For both parties, seller and customer, it matters that the dispensed volume is measured to ensure an honest transaction.

The above example was rather a volume-, not flow-measurement.
In many other processes where you can think of flow-measurement, the real reason for measuring is not the measurement itself.
The measured flow is a process-input and is compared to the limit- or reference values. It’s easy to imagine that, if a deviation is found, either an alarm, or an automated correction is issued. A fairly reactive way of controlling if you ask me.

bewaking koelcircuit

Think further

Why install a flowmeter and respond in a reactive manner to a situation that is already deviating from your nominal process?
Why not install a flow-control instrument, taking care of a constant flow, preventing deviations?
The answer to this question is probably the fact that liquid-flow-control is not a commonly known solution (yet).

Flowmeister challenges you to think further.
Is your flow-application one where a constant liquid flow is really the goal?
Would a closed-loop feedback and control system -keeping a steady flow, independant of pressure- make you feel more confident than your current set of instrumentation?
Q-dose might just be the solution you have been trying to build sofar.

What is Q-dose?

Q-dose is a setup that starts with an ultrasonic flowmeter with integrated PID-feedback system.
When the flowmeasurement notices a difference between actual flow and the given setpoint, the PID-function will adapt the output signal.
The change in output signal makes a proportional valve act and compensate for the measured difference.
This feedback-loop ensures a stable flowrate, thanks to a number of technical details, both in the flowmeter as in the controlling loop and principle of actuation.

May I help you?

We appreciate a personal touch

flowcontrol is often the real requirement behind an installed flowmeter
Application, FlexAct, BioWelder, SC Dynamics, Sartoclear Dynamics, STR 2000, Biostat STR

Fast Flowmeter application

Sometimes a process is thát critical and each deviation in flowrate must be noticed and compensated for.
A customer application involves water with potentially some short disturbances in flowrate.
With water as medium, lots of measurement methods can be used to measure flow, why chose Ultrasonic measurement then?
The reason is in the additional requirements.

Requirements mark the playing ground

There’s always more than one requirement when a flowmeter is being considered. In this Fast Flowmeter process, speed was obviously key-requirement number one!
Next to a quick response, it would be beneficial that the flowmeter would disturb the water-flow the least possible.
In addition, and related to that, a minimal pressure-drop could be allowed, pressure plays an important role in this customer’s process.
A last requirement has to do with accuracy and scaling. The current maximum flowrate is 12 liters per minute. This may rise a bit in the future, so additional capacity is not bad, but 12 l/min should be in the accuracy-range of the instrument.

Weighted requirements

In itself the above requirements would qualify for four types of Flowmax ultrasonic flowmeters.
To come to a ranking, the requirements are weighted, the most critical requirement is counted five times, the least important only once.
By judging with weighted requirements, it became obvious that the Flowmax 44i has the best overall score.

From good to better

All four considered flowmeters are equally fast, have an open bore and no moving parts. On that behalf, they are all good.
What made the difference is the close-to-straight bore of Flowmax 44.
The straight bore of DN10 matches ideally with the piping inner diameter. This results in low pressure-drop and in less noise in the flow itself.
Great how a non-critical parameter can make a small diference at the end.

How fast is Flowmax-fast?

The application may have minor disturbances that may last no longer than 0.1 second. Or 100 milliseconds to make it sound more 😉
Flowmax sensorics deliver 250 internal measurement values every second, that’s one reading every 4 milliseconds (!)

A minimum damping level is hard-coded in the Flowmax calculator, averaging each 4 measurements and providing the outcome as an output to the world. That makes the fastest rate 4×4= 16 milliseconds.
Do you have 3.05 minutes? Watch this video of the importance of milliseconds for athletes.!

Reduced speed on demand

On demand, the user may want to increase damping of the signal.

With increased damping , the meter still takes 250 measurements per second.
The difference is that a lot of things happen inside the calculator, with an end-effect resulting in one output signal every 2 seconds for example.
This damping is an important factor in PID-control cycles.

Optional: PID in the meter itself

PID software is optionally available in the Flowmax instruments. Tell us your aplication and get fast advise.

(This may take more than 16 milliseconds)



Eire flowmeter – Ireland

Ireland has an impressive industry in bio-pharmaceutical companies.
The world-wide top ranking of medicine-makers, at least has a plant in Ireland.
Given the fact that bio-medical production often invloves liquids, the Irish industry has a need for instrumentation for liquid-monitoring and -dosing.

Not an ordinary instrument

Process-control solutions in regular industries form the basis of instruments which can -and are allowed to- be used in hazardous processes such as bio-pharmacy.
The proven technology has to be translated into a capable design, approved materials, methods and shapes.
Once functional, the instrument will undergo an intensive trajectory of validation and approval before it can be introduced commercially.

Flowmeister is proud to intoduce the Eire Flowmeter for ireland. It’s a high-end solution, with the requirements properly in place for a quick plug-validate-play scenario.
Developed in 2014-2015, the MIB Flowmax 242i, a Single Use ultrasonic flowmeter, is readily available.


Less is more

Ranging from 0.015 liter per minute up to 24 liter per minute with four different measuring-tubes we believe to offer solutions to cover the spectrum of regular applications in the bio-pharmaceutical industry.
Knowing that the cost of an ultrasonic instrument is somewhat more than simple meters, it’s good to bring some relativity in the scale.

A first factor is a matter of smart design.
Only the wetted parts are to be disposed, the valuable calculator and electronics remain for a lifetime.
Secondly, the accuracy is high, better tan 1% of measured value, even at fluctuating flowrates! Ultrasound is fast, we give you a measurement every 16 milliseconds (if you like).
Thirdly, the instrument has a free bore, with no obstacles no moving parts and only one wetted material.

Inquire for your Eire Flowmeter

A soon response is ensured!

Your instrument has been tested, which is certified with the delivery. Optionally, a 3- or 8-point calibration-certificate can be ordered to prove the exact accuracy.

Before you submit:

you may trust an honest advise. If FlowMax is not your best possible solution, I will explain you why that is.

Feel free to have a look at the manufacturer’s website.

Flowmeter chemical and chemics

flowmeter chemie

<Dutch version here >

Within chemical processes, a controlled and regulated flowrate is one of the key-parameters to ensure a safe and succesful process.
The top-three features in this sector are:
– Safety
– Reliability
– Repeatability
The ultrasonic flowmeter for chemicals robustly fills in these three demands. In addition, the instruments are fast and accurate, which is an advantage in processes with fluctuating flow, such as fast dosing processes.

Chemical Flowmeter is all about material-properties

Each aspect in a product-design is important, but for the chemical flowmeter the choice of materials is crucial.
Imagine one of the wetted parts being insufficiently resistant to your fluid, what would the consequences be….?
If safety cannot be guaranteed, who wants to know about reliability or repeatability?

The MIB flowmeter named Flowmax, is not a one-size-fits-all solution, it is a whole range of instruments with different shapes and materials.
Besides some specific properties, all instruments have five important features in common:

– Plastic housing
– Free bore
– No moving parts
– Smooth inner surface
-No electrodes or metals, just one wetted part!

Some examples of Flowmax

PSU polysulfon flowmeter chemie



The basis instrument is Flowmax 44i, made of PolySulfon (PSU)
This typical black shiny housing is injection-moulded, resulting in zero gaps or joints in the wetted area.
Usable for multiple properties of conducting or non-conducting liquids, but not for Chloride.






PVDF flowmeter chemie


A real pro in chemical flowmeasurement is Flowmax 400, made of PFA and also injection moulded.
Its usability excels in the lower flowranges, down to one liter per hour.
Integration  in tubing systems makes a perfect fit with the integrated flare-connections.
Adaptor to threaded process-connection is optionally available.




undisturbed flow measurement
Flowmax 54i shown in HDPE, optionally available in PE-Xc


Higher flowrates up to 900 liter per minute are possible with the Flowmax 54i range. The machined body gives additional flexibility in material and process-connection.
Standard material is PE-HD because of the good properties in lightly aggressive media. Process connection is outer thread.
Flowmax 54i is also available in the extremely resistant PE-Xc and in poly-propylene (PP).
Customized process-connections are possible on demand.



flowmeter chemie Flowmax 242i


Another variant is Flowmax 242i, also in a machined PE-HD body with possibilities and certification for application in bio-chemical and bio-pharmaceutical environments.

Not just any material, but the result of a fully validated and certified design-trajectory.

What’s particularly interesting is the re-use of the standard electronics housing (in black PSU) whilst the wetted measuring-tube is made of the mandatory certified PE_HD.


Link: Polystone-P-MED-natural-homopolymer-FDA-compliance



Flow-measurement and dosing of chemicals -> start with a good advise! 

Flowmeister believes that knowledge is here to be shared.
Let me know your problem, challenge or idea and expect a soon reaction!

Feel free to have a look at the manufacturer’s website.

New material PE-Xc for PE Flowmeter

plastic flowmeter

Application-driven development leads to new products. This is an overview of high-end flowmeters in PE-Xc

Why develop Flowmax in PE?

Flowmax has been available in chemically resistant materials since years.
Why making the addition to existing Flowmax series in PSU and PFA?
MIB GmbH has developed the Flowmax in HDPE for two reasons:

Reason 1: Flexibility
Existing Flowmax 44 (in PSU) and 400 (in PFA) are based on die-casting. This is a good manufacturing-process, but is limited in flexibility because of the existing moulds.
The ability to machine every shape allows for a wide range in:
– integrated process-connections such as Tri-clamp, hose-pillar or threaded.
– different bore-diameters
– customer-specific mechanical mounting
– customer-branding / logo integration

PE flowmeter BKS clamp
PE-flowmeter body with integrated process-connection (BKS-camp)

Reason 2: Material-properties
The material-properties of PE are interesting for the applications we support.
First of all, PE is available in a FDA-approved version. This is a basic need for our Single Use Flowmeter Flowmax 242i
Secondly, the base-properties of HDPE offer a great portfolio of chemical resistance.
Thirdly, the standard HDPE can be upgraded to withstand extreme situations, see below for more details.


Improved material properties for PE-HD

High Density Poly-Ethylene (HDPE) has proven to be a useful basematerial for industrial components.

To achieve maximum performance, a treatment can be done to convert the material properties to a higher level.
The molecular structure of regular HDPE will migrate to a stronger 3D structure with an after-treatment. The improved material is named PE-Xc. (X stands for cross-linked, c represents the after-treatment delivering the sublime material properties).
In daily German operation, the HDPE-Xc version is also known as PE-HDV (V stands for ‘vernetzt)

Available flowmeters in PE-Xc

Flowmax offers a range of instruments in HDPE, most of them in PE-Xc upgrade as well.
Typically the Chemical Applications benefit from the increased properties. (Link in Dutch)

Flowmax 42i is the initiator of the HDPE-versions.
Main reason for its existence was a reduced bore-diameter in order to lower the measuring range for a pharmaceutical application.

PE flowmeter
Flowmax 42i with the typical darker colour of PE-Xc




Low-flow bore, customer specific process-connection and FDA-approved material came together in the design of the Flowmax 42i measuring tube.

The standard electronics have been integrated in the Flowmax 42i body.
Demanding applications can be fulfilled with the Flowmax 42i in PE-Xc material.

Quickly after approval of the Flowmax 42i, the pharmaceutical customer requested a Single Use version of this PE Flowmeter.




This Single Use request eventually resulted in Flowmax 242i M, a separate measuring tube out of FDA-approved PP, with remote electronics.

PE flowmeter Flowmax 242i
Flowmax 242i M separate measuring tube and electronics


For bio-pharmaceutical use, the PP material is excellent and the MIB-standard.
Still, the body is available in HDPE or HDPE-Xc on request.

Either PP or HDPE: a material certificate is available of course!






A third line in HDPE is the newest instrument, Flowmax 54i.
These instruments typically address higher flowrates such as cooling-circuits or high-volume chemical processes.
The three versions (DN32-40-50) are available in PE-Xc as well, making them optimally equipped for higher temperatures and mechanical wear when measuring abrasive slurries.

undisturbed flow measurement
Flowmax 54i shown in HDPE, optionally available in PE-Xc

Why Flowmax in PE-Xc?

Want to know more about the specific properties and how a PE Flowmeter (or PE-Xc)  will improve your application?
Just give us a sign using the form below and receive our response within two working day!

Requiring EHEDG-design and good chemical resistance? Have a look here …