Welcome to the Spring 2017 issue of fLowdown - a quarterly Newsletter from Titan Enterprises Ltd. written to keep you informed about the latest technological developments, applications advances and breaking news in the field of flow measurement.

If a particular feature interests you, do not hesitate to contact us or follow the link for further information. We welcome your feedback.

Trevor Forster (Managing Director)

 

Trevor's
Technical Tip

Trevor Forster is Managing Director of Titan Enterprises. His experience in fluid handling dates back to the mid 1960's when he started working on rotating seals and flowmeter design for third party clients. Trevor draws upon over 40 years of using innovative design and production techniques to produce elegant flow metering solutions for organisations around the globe.
In this issue - Trevor offers you useful technical tips on:

Flow meter calibration techniques

There are numerous flow meter calibration systems. Each method has its own pros and cons and the best method to select will depend upon the size of the meter and the required outcome.

Bucket and stopwatch

This is a commonly used calibration method for a quick flow meter check and for lower flows it is quite a viable method. It is less suitable for extremely low flows or volatile or aggressive liquids as evaporation will cause serious errors and safety must be paramount. Measuring the volume, or preferably the mass of a fluid, of known density, is crucial and the time spent highly relevant. If the steady rate flow can be started and stopped very quickly even better. Ideally a relatively large volume should be metered over a long time period as this reduces the errors. A set of calibrated scales with a suitable capacity for the speed of discharge over the time period can be used. For example a ½-inch meter running at 20 litres per minute of water would require a set of scales with a capacity of perhaps 50 Kg. This would allow for a two minute flow run and some "tare" for the weight of the water container. Ideally the scales should have a 0.1Kg resolution so that the recorded resolution would be ±0.1 in 40 Kg i.e. ±0.25%. Factoring in possible timing errors over a 2 minute run i.e. ±1 second in 120 the combined uncertainty becomes ±1.1% which may be acceptable for a quick check. From this crude example it is easy to see how inaccuracies and uncertainties build up even when care has been taken with the set-up and execution of the test.

Flying start/stop

One of the oldest methods of flow meter calibration is an extension of the 'bucket and stopwatch' approach where a custom diverter is coupled to an electronic clock and counter system. A "knife" edged diverter cuts a narrow stream of fluid and simultaneously starts a counter and timer at the centre point of the diversion. It could also be a diverter valve which is specially manufactured to ensure no change in flow during diversion. In either case the flip-over must be quick and consistent to guarantee repeatability (see figure 1 below). The chart below (Figure 2) shows the importance of consistency during the changeover. Ideally the lost and gained volumes of fluid are equal and opposite. Using this method, the faster the diversion the less inaccuracy in the diverted volumes.

Figure 1


Figure 2

Volumetric measurement

For many applications a volumetric measurement can be made and compared to a total recorded on your flow meter. Such volumetric measurement vessels are usually calibrated with a narrow neck for better resolution and accuracy at around the vessels designated volume. Volumetric measurement vessels are calibrated at a given temperature and sometimes given a temperature coefficient for variations from the reference point. Figure 3 below shows an old weights and measures approved ½ pint flask showing the +3ml / -3ml acceptable tolerances. This particular flask is rated at 20°C.

Figure 3

Piston provers

Piston provers are fundamentally as simple as they sound. They are not unlike a hydraulic ram with a linear encoder attached to it. The diameter of the piston is known and the encoder will give a certain number of pulses for every litre of liquid dispensed. The drive system for a piston prover can be pneumatic, hydraulic or even a stepping/servo motor. It does not matter as long as the output is continuous and controllable. The clever part is the way the output from the encoder and the flowmeter are dealt with. In a piston prover the two pulse counts may not be synchronous and one has to act as a gate for the second. The primary is usually the linear encoder and constant flow is essential for accurate interpolation. The lag between the first pulse from the flowmeter after the encoder "start" pulse, as well as the corresponding stop signals after the predetermined volume of fluid or number of pulses have to be recorded. The actual number of pulses can then be determined for a known volume even though the two signals are not synchronous. It is important in piston provers that the actual pulse widths are constant as irregularities will cause "jitter" in this double timing system. Corrections can be applied for temperature and pressure variations.

Pipe/Ball provers

These are used where other calibration systems are impractical or high accuracy is required such as custody transfer stations handling oil products. They can be fixed installations or even skid mounted and driven to a site, perform a calibration and be driven away again. Like the piston prover a "displacer", often a sphere, is introduced into the pipe and pushed by the fluid passed a start and stop detector positioned a set distance apart. The swept volume is determined by calibration. Pipe and ball provers can be uni- or bi-directional depending on the valve arrangements. Typically pipe and ball provers are extremely accurate (±0.05%) and often used in large diameter pipe applications.

Transfer standards

One of the easiest ways to calibrate an inline flow meter is to use a transfer standard. However for best accuracy this must be operated under the precise conditions under which the meter was calibrated. One of the advantages of this method is the fact that the flow meter under test and the reference meter can be in series in the same line. The accuracy of such a system is one step further away from a traceable reference but this is often an acceptable factor. Several companies offer meter hire for such applications.

Calibration of flow meters
at Titan

Titan Enterprises have used piston provers for flow meter calibration since 1994. Our primary rigs are rated from 0.004 to 40 and 160 litres per minute. With recent software upgrades our low end flow calibration has been reduced to 2ml/min. All Titan flow calibrations are traceable to national standards and have real time temperature compensation to accommodate changes in the fluid properties. Our piston prover systems are calibrated regularly and are pneumatically driven to ensure a constant flow rate.

For lower flows we have a bespoke micro piston prover. This is driven by a very high resolution servo motor the speed of which can be controlled accurately with no pulsations in the axle speed. The ball drive to move the small bore piston is driven by a precision toothed belt through a pair of reduction sprockets. Like the main flow rigs the volumetric throughput is traceable to national standards via a water draw test. Flows as low as 0.1 ml/min may be calibrated using this rig.

For further information on flow meter calibration services at Titan please click here.

Flow Technology Spotlight

In this issue of fLowdown we look at the Importance of Investment in Research and Development.

Leading UK technical innovator - James Dyson has announced a massive expansion of his research and development plans. Figures of over one billion pounds have been quoted in the press. His team of engineers, only nine hundred a few years ago is going to increase to some three thousand five hundred over the next few years. He is passionate about British technology.

At Titan we share this passion. The only way for a company to expand, or for that matter remain competitive in the global market is to ensure that its products and technologies are ahead of the competition. Unlike Dyson we do not have a an English Electric Lightening jet hanging from the ceiling in our canteen. Infact we do not have a canteen but if we did I would gladly hang some British technology from the ceiling. Perhaps a Harrier jump jet or Whittle jet of some sort. In the foyer at Titan’s UK headquarters would be the double acting triple expansion steam engine from the SS Glen Strathallan which I worked on as a student that is now placed in between the iconic first steam powered machines in the science museum the likes of which changed the industrialised world. Technology is fundamental to the well-being of a company and a country.

Over the past few years - Titan has spent some 15% of our turnover on R&D. The national average is around 4%. This level of investment puts us ahead of 3M, Samsung and GE but behind Google, Tesla Motors and Facebook. Our level of spending is in good company. We have developed new ultrasonic algorithms unseen in the technical press, devised new methods of extending the operational time of battery power LCD instrumentation and produced our own ultrasonic algorithm operating and recording system. We are in the process of developing wide ranging (3000:1 operating range), low flow (3ml/min) and high pressure (1350 Bar) ultrasonic meters for demanding applications. We believe these new algorithms will permit us to produce accurate small bore clamp-on ultrasonic meters for medical and ultra-pure applications that will be accurate to better than ±2% between tube changes.

For further information on these latest technical innovations from Titan please click here.


How do I measure?

In this issue of fLowdown we discuss:

How do I meter applications with low flows ?

Metering applications with low fluid flows is difficult. Mechanical flow meters typically cannot extract enough energy to give linear results. By comparison, electronic flow meters often have problems with sensitivity, zero drift and response times. Below we look at technologies proposed for low flow applications and their corresponding pros and cons.

Variable area meters

The ubiquitous ball in a tube flow device commonly referred to as a Rotameter. Variable area meters have been the backbone of measuring low flows in laboratories for many years. Unfortunately they are not very accurate at lower flows, typically ±5% for a given set of conditions. This meter type also suffers because changes in liquid properties will change the height the float attains and so the flow rate indication. Variable area flow meters typically do not offer an electronic output.

Low flow axial turbines

Axial flow turbines do not work well at low flow. The energy required to spin the rotor becomes swamped by the drag from the system at low flow rates. Other factors such as changes in fluid density or viscosity will also affect your calibration. These devices provide best results for metering turbulent flow which is rarely seen with low flows. Some small polymer axial turbine devices have been quite successful in metering low flows but changes in fluid properties are still an issue.

Pelton wheel turbines

These radial flow devices work better than their axial counterparts with lower flows but still have similar problems. Titan and several other manufacturers try to reduce the drag that occurs with the transition from turbulent to laminar flow but the linearity still changes as the flow reduces. Bearing drag is also an issue but with Pelton wheel turbines as the system design does permit low friction bearings.

Titan's first patent for a low flow flow meter was for a radial flow turbine which had no blades. Two plain discs on low friction bearings were placed 0.8mm apart and a 0.8mm jet of liquid was injected into the gap. The fluid in the gap acted as the resistance to the incoming jet and rotated the discs. Having no blades to "stir" the fluid the overall drag on the system was much reduced. Flows down to 0.5 ml per minute were successfully recorded with this "bladeless" turbine. We no longer make this product as it was very expensive to produce and has been superseded by our ultrasonic technology.

Positive displacement meters

Positive displacement meters can be very good at metering low flows of viscous fluids but their resolution tends to be quite low. For metering low flows of aqueous solutions they are very poor as the "slip" past the various moving elements is greater than the volume being measured. There are some specialist high precision positive displacement devices which are successful but they are typically fluid specific and expensive.

Thermal meters

Thermal devices often offer good performance for metering low flows. Unlike the previous technologies with a thermal flow meter there is energy injected into the system so the meter is not so reliant on the dynamics of the fluid to make the measurement. They are still fluid specific as they rely on the fluids thermal transfer properties. Typically these devices have slow response times.

Electromagnetic meters

Electromagnetic meters are another example of a flow device that does not rely on the moving fluid to do any "work". As velocity measuring devices - electromagnetic meters rely on an induced voltage in a moving conductor, the fluid. They will not work with non-conducting fluids so a vast number of liquids are excluded from their measurement capabilities.

Coriolis meters

A few manufacturers have introduced Coriolis meters into their product ranges. They are very sensitive and record low mass flows accurately. Unlike the preceding thermal and electromagnetic devices this meter does require the movement of the fluid to react with an energy input from the system. Unfortunately these devices are very expensive when compared with other technologies.

Ultrasonic meters

Ultrasonic flow meters are probably the newest addition to the low flow metering armoury due to their ability to make ultrasound travel within the fluid in a small pipe over a long distance. Over the last 10 years - Titan has developed several generations of ultrasonic low flow flowmeters based upon a patented time-of-flight design able to measure the velocity of the fluid within the pipe. The very high signal to noise ratio from these devices has been widely proven to enable metering of extremely low flows with great precision.
  

For further information on Titan’s latest generation of ultrasonic flowmeters for low flow applications please visit www.flowmeters.co.uk/atrato-ultrasonic-flowmeters/


Engineering Apps for Mobile Devices

An app is a software program for your mobile phone. These programs range in size and complexity from a simple flashlight application to a comprehensive navigational system for plotting positions on a marine chart. Apps allow you to customize a mobile phone or tablet to your specific set of wants and needs. They are generally easy to install, and once you start using them, will become a necessary part of your mobile life.

To save you the time and trouble of searching for and finding useful Engineering Apps we have already done this for you. Part 2 of our informative feature on Engineering Apps is detailed below.


Mechanical Dictionary

A comprehensive glossary of terms, spanning around 35,000 entries, which are constantly being added to. Some features include a search history, saving definitions, adding new definitions and the ability to quickly google search if necessary within the app. The app is available for free on the google app store.

Further information


Graphing Calculator

Mathematically useful, a basic graphing calculator is a handy tool to have. This application features a highly interactive graphing function, along with a scientific calculator and the ability to save graphs. Ideal for anyone needing a graphing calculator. The app is available for free from the google app store.

Further information


Product Preview

Non-invasive ultrasonic flowmeter
for challenging liquids

MetraFlow® will be a further addition to our expanding ultrasonic flowmeter range available for sale by the third quarter 2017. It utilises Titans latest patented technology to give a straight through construction. The flow tube is just that - a chemically resistant PFA (or alternative material) tube onto which are mounted our ultrasonic sensors. There are no dead areas, changes in fluid direction or obstructions, just a tube. MetraFlow® uses our highly accurate, ultrasonic time of flight algorithms to give a wide range meter with an unprecedented accuracy of ±1% of reading over the top 50:1 flow range and ±2% from the minimum flow. There will be two flow ranges 1/8” tube - 10 to 1000ml/min and ¼” tube - 50 to 5000 ml/min. USB interconnectivity makes the meter easy to set-up and use whether it is the digital or analogue outputs being used or both. The local display gives rate and total as well as annunciators for units and time base.

For further information on the MetraFlow ultrasonic flowmeter please click below.


Product Update

Low power 800-series flowmeter for battery
operated equipment

Titan has introduced a new version of its popular 800 series turbine flow meter that enables integration with battery powered or portable equipment. Designed to operate with minimal power input, this competitively priced, low power 800 series flow meter maintains high performance over 6 flow ranges from 0.05 to 15 litres per minute. Totally non-metallic wetted components, including a moulded PVDF body and Viton 'O' seals, makes the lower 800 series flow meter the ideal choice for the metering of even aggressive chemicals. The standard inlet tubes are barbed to accept a hose size of 8mm although for OEM use - alternatives are available.

At the heart of the low power 800 series meter is a precision turbine that rotates freely on robust sapphire bearings. The turbine contains fully moulded-in magnets that are detected through the chamber wall by a extremely low drag, low power detector. The output for the low power 800 series flow meter is a stream of pulses that are readily interfaced with most electronic displays or recording devices. This combination of materials and technology ensures a long life, high performance product with continuous reliable operation.

For further information on the new low power 800-series flow meter please click below.


Bulletin Board

Titan Launches New Responsive Website

Titan Enterprises has launched a new responsive website which ensures visitors automatically enjoy a perfectly formatted viewing experience from a desktop, tablet or mobile device. In response to customer demand we have produced a series of new selection charts which enables you to quickly select which Titan product is the optimum choice in terms of handling the fluid type, flow rate, maximum pressure and maximum temperature your application requires.

For further information: visit www.flowmeters.co.uk.



Titan produce new suite of technical product data sheets

Following a series of products introductions and many product updates over the last few years – Titan Enterprises has published a suite of 24 new data sheets and seven new instruction sheets. Following a common format each data sheet provides a wealth of information including product description, product photograph, key features, target applications, dimensional drawings, technical specifications, materials of construction and ordering information.

For further information: visit www.flowmeters.co.uk.

Senior Engineer Sought By Titan

Titan Enterprises are looking to recruit an experienced project/development engineer with knowledge of flow measurement to be responsible for all engineering and technical aspects within the organisation. The successful applicant will schedule, plan, forecast and manage all the technical activities aiming at assuring project accuracy, viability and quality from conception to completion. Key responsibilities will include to Prepare, schedule, coordinate and monitor engineering projects ; Monitor compliance to applicable codes, practices, QA/QC policies, performance standards and specifications ; Interact regularly with the clients to interpret their needs and requirements ; Perform overall quality control of the work (budget, schedule, plans) and report regularly on project status ; Cooperate and communicate effectively with the company directors ; Review engineering deliverables and initiate appropriate corrective actions and Support sales in both a technical and commercial capacity.

To request full details of this exciting role please contact kate@flowmeters.co.uk.

 

Humour

While there may be many things currently happening around the world that worry you …
here are a few bits of humour to make you smile !


You are probably an Engineer if...
... your three year old child asks why the sky is blue and you try to explain atmospheric absorption theory to them.
... you consider yourself well-dressed if your socks match.
... you have a non-technical vocabulary of 800 words or less.
... you know the second law of thermodynamics but not your shirt size.
... you make 4 sets of drawings (with seven revisions) before constructing a bird bath.
... politically correct people call you "organizationally challenged."


An engineer, a physicist, and an accountant were being interviewed for a position as chief executive officer of a large corporation.
The engineer was interviewed first, and was asked a long list of questions, ending with: "How much is two plus two?" The engineer excused himself, and made a series of measurements and calculations before returning to the boardroom and announcing, "Four."
The physicist was interviewed next, and was asked the same questions. Before answering the last question, she excused herself, made for the library, and did a great deal of research. After a consultation with the United States Bureau of Standards and many calculations, she also announced, "Four."
The accountant was interviewed last, and was asked the same questions. At the end of his interview, before answering the last question, he drew all the shades in the room, looked outside the door to see if anyone was there, checked the telephone for listening devices, and asked, "How much do you want it to be?"


Q: How do you confuse a chicken?
A: Put it on a Möbius strip.

Click here for a printable version of Flowdown.

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Titan Enterprises Ltd, Unit 2, 5A Cold Harbour Business Park, Sherborne, Dorset, DT9 4JW. UK
Telephone: +44 (0)1935 812790   -   Fax: +44 (0)1935 812890   -   Email: sales@flowmeters.co.uk