Leaps in Technology, and the spin-off

Whilst pacemakers and other implants have become fairly commonplace in medical treatment systems, these still rely on battery technology, and have a limited life. When dealing with electrodes or sensor devices positioned carefully, sometimes deep in the body, a battery capsule is embedded under the skin, to enable future access for replacement. A new development project at MIT, to be more fully described at an August conference, describes a very small medical implant that can be powered and interrogated using radio frequency waves, even though it is deep within the body.

Medical devices that can be ingested or implanted in the body could offer doctors new ways to diagnose, monitor, and treat diseases. In their study, the researchers tested a prototype about the size of a grain of rice, but they anticipate that it could be made smaller. Giovanni Traverso, a research affiliate at MIT’s Koch Institute for Integrative Cancer Research, is now working on a variety of ingestible systems that can be used to deliver drugs, monitor vital signs, and detect movement of the GI tract.

In the brain, implantable electrodes that deliver an electrical current are used for deep brain stimulation, which is often used to treat Parkinson’s disease or epilepsy. Wireless brain implants could also help deliver light to stimulate or inhibit neuron activity through opto-genetics.

In animal tests the researchers have shown that the radio waves can power devices located 10cm deep in tissue from a distance of 1m. Until now, this has been difficult to achieve because radio waves tend to dissipate as they pass through the body. To overcome that, the researchers devised In Vivo Networking (IVN), a system that relies on an array of antennas that emit radio waves of slightly different frequencies. As the radio waves travel, they overlap and combine in different ways. At certain points, where the high points of the waves overlap, they can provide enough energy to power an implanted sensor.

Mobile phone developments

The ubiquitous mobile phone. In various past articles I have mentioned the spin-off effects of the technology behind telecommunications and the mobile phone being used to create new industrial sensors, relying on the research and the production capabilities for the devices required for the industry. These spin-offs include the rise of radar level measurement systems, the use of wireless in many industrial sensors, and also the availability of many laser diodes, used for interferometry, liquid analysis etc.

Another major development is that of the liquid lens, used in these same mobile phones. This gets really personal, as for the last 60 years I have been an avid aero-spotter, keenly watching light aircraft arrive at our local airport using a telescope to identify them. Then, on arrival at or near the airport, using long and heavy telephoto lenses to photograph them. Later, I collected antique telescopes, manufactured from 1780 to maybe 1850, as they were still really the best quality optical systems, despite modern (commercial) developments. Again, long and heavy things.

But along came the liquid lens. This is a very small lens device, now commonly used in iPads and mobile phones. The liquid droplet forming the lens has its shape changed electronically, using an electronic control system. This is able to change focal length (to focus) and change optical axis (for optical image stabilization, ie to reduce camera shake effects) – all within a few milliseconds.

The idea for this invention came from research on the phenomenon known as “Electro-wetting” by Professor Bruno Berge, in Lyon, France, with the original patents being issued in 2002. Prof Berge started working on liquid interfaces from 1991 at the Ecole Normale Supérieure in Lyon. A drop of water affected by electro-wetting can function as a variable magnifying glass: so two clear, non-miscible liquids of the same density, one being electronically controlled water, can serve as a lens, depending on the curvature of the interface between them. The two liquids are sealed and held in a metal casing that is typically smaller than 10mm in diameter.

Berge first approached Canon cameras with the invention, but attracted no funding. So with French state funding, and investment fund backing, Berge founded the company VariOptic in 2002. In 2007 they established a production line in China, and in 2009 the first industrial barcode reader with a VariOptic lens appeared on the market. Machine vision manufacturer Cognex was an early adopter of the technology, for barcode ID readers.

A new module now available from IDS (Imaging Development Systems) is a single board USB interface camera, available for use with and control of liquid lenses. These low-cost uEye LE industrial cameras with twist-proof USB Type-C connection and practical USB power delivery are quoted as interesting for logistics systems (eg for package acceptance and sorting), for microscopy and traffic monitoring, as well as for installation in small medical or industrial devices.

So, I am still waiting for a lightweight long focal length telephoto ‘liquid’ lens for my Canon camera. Maybe not the telescope – for as I pointed out to Prof Berge, one of my favourite telescopes dating from the 1790s was made by Matthew Berge, his namesake!

The full story about the Prof Berge development of liquid lenses was first reported by me as the very first blog post on www.telescopecollector.co.uk, back in December 2013.

This article was first published in the South African journal of Instrumentation and Control issue of August 2018, published by technews.co.za

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MVDC Power Transmission

Azeez Mohammed, president & CEO of the GE Power Conversion business discusses how MVDC technology is creating a more secure and higher-capacity grid for the future. Thanks to the MCDC technology, Scottish Power Energy Networks’ Angle DC project – first of its kind in Europe – will provide a 23% power capacity increase for supplies to Anglesey. Similar technology is being used in offshore wind applications, giving up to  15% cost savings.

Transforming Power Grids for an Efficient Future

With a fast-growing global population and increasing levels of industrialisation, demand for electricity is expected to soar 60% between now and 2040. That means power grids will be called on to transmit more power, more efficiently. And to do so, they’ll have to adapt to an evolving energy landscape.

Today’s grid is still structured around transmitting electricity from a handful of large, centralised power plants running on coal, oil, gas and nuclear. While these will continue to dominate the mix for years to come, renewables are increasingly making their presence felt – and are expected to supply a third of global power by 2040.

With renewables growth comes an increasingly diverse distribution network – from remote and offshore generation sites to microgrids. All must be brought together to ensure we continue to have a reliable, resilient power supply. The challenge now is that the majority of power grids are made up of decades-old infrastructure that’s simply not – yet – up to the task.

Laying the foundations

Creating a future-proof power grid means fusing time-honoured knowledge with forward-thinking technology. For over 100 years, GE electrical engineers have recognised that DC electricity transmission is more efficient than AC. Now, DC is becoming more prominent – both at the beginning and end of the grid. DC is produced by wind turbines and solar PV and used by everything from smartphones, laptops and electric cars to the data centres that keep our digital world up and running. However, having to convert back and forth between AC and DC along the way leads to wasted energy through resistance and heat.

AC may have won the “War of the Currents” that raged between the Edison Electric Company (which favoured DC and would become General Electric) and Westinghouse (which favoured AC) in the 1890s. This was due to its ability to easily step up voltages to the higher levels needed to transmit it over long distances and back down again for safe usage. But today, new power conversion and transmission technology means it is becoming more cost-effective to use DC to transmit at higher voltages, with less energy losses. The same attractive cost story applies when it comes to integrating new, often remote, DC-producing renewables into the wider grid network.

At the GE Power Conversion business, we’re developing the use of DC to enable more efficient power transmission to and from remote areas – both onshore and offshore.

Strengthening the Anglesey power supply

At the GE Power Conversion business, we are delivering Europe’s very first medium-voltage direct current (MVDC) link as part of the Scottish Power Energy Network Angle DC project in Anglesey and surrounding North Wales area. A growing demand for electricity in the region, combined with increasing volumes of renewable generation, is putting the existing 33-kilovolt AC links between the isle of Anglesey and the Welsh mainland under strain.

Converting the existing AC connection to MVDC could help it to carry more than twice the power and do so more efficiently. GE MVDC technology is providing a critical project asset, as it allows for the creation of a more-secure, higher-capacity grid without the need to overhaul existing infrastructure or install new power distribution assets.

Instead, GE will install MVDC power modules at the two existing substations in Bangor and Llanfair PG, where the AC to DC conversion will be performed. GE MV7000 power electronic inverters will transmit the power via the existing 33-kilovolt AC overhead line and cable circuit, increasing the power available to Anglesey by 23% to meet its future needs without additional environmental impact. What’s more, the DC equipment will assist in the provision of further grid support, as the inverters are able to support the AC voltage at each substation.

This MVDC technology works in much the same way as our high-voltage direct current (HVDC) projects, but on a smaller and simpler scale. For example, a comparable HVDC system would operate at 320-400 kilovolts DC, whereas the Angle DC project will operate at 27 kilovolts DC—demonstrating how this technology can be scaled to fit a variety of customer needs.

Lowering the cost of offshore power

From wind turbines stationed far out at sea to solar farms in inhospitable deserts, renewable generation networks are often found in hard-to-reach places. Getting the power generated to a centralised grid via AC can waste energy and keep renewable electricity costs higher than they need to be.

Now, similar technology behind the MV7000 converters used for Angle DC has also been successfully trialed for use in remote power networks. Our PassiveBoost solution will enable DC power transmission, opening up the potential to boost electrical output from these remote sites while also reducing power costs.

PassiveBoost is an MVDC converter which provides a straight replacement, with the same footprint and volume, for the AC transformer inside every wind turbine. This helps to facilitate a direct connection to an efficient MVDC power collection grid, resulting in a lower cable cost and no need for an expensive and complex DC breaker. A 6 megavolt-ampere converter was designed and tested at the GE power test facility in the UK. There, it successfully demonstrated the capability of generation, distribution and protection at MVDC, highlighting efficiency levels that could bring a 15% cost saving for offshore wind electricity by significant reductions in component count, cabling costs and removal of need for offshore platforms.

Greater grid control through data-driven insights

To drive further efficiency across the power grid, GE can also offer VISOR 2.0, an asset management tool that provides remote connectivity to key assets. This not only enables an improved service response time, but also access to real-time support and advice in the event of a fault or problem. By pairing this tool with the GE Data Historian, which collects, processes and stores data, customers can more easily review the capabilities of their MVDC system. Its ability to capture and analyse data about asset performance means customers can then develop optimum control algorithms for the distribution system, helping to ensure the grid is always functioning as effectively as possible.

As electrification within all industries gathers pace and the burden on existing energy distribution networks increases, we’re ready to put our expertise into action where it’s most needed.

 

Technology disruption, and profiting from university R&D

It is almost a part of engineering folklore that the UK is slow to realise the potential of its inventions. The jet engine, computing and television are perhaps the best-known examples of British inventions whose financial benefits were mainly exploited by other nations. Lithium-ion technology is another that was developed in Britain, in fact in Oxford, but was commercialised mainly in the US and East Asia. However, this was not a failure of foresight but merely a misfortune of timing – the initial invention came many years before the development of mobile phones and camcorders which were the most fruitful early applications for lithium-ion batteries.

The Faraday Institution was then set up as the UK’s independent centre for electrochemical energy storage science and technology, supporting research, training, and analysis. Its function is to bring together expertise from universities and industry, and they are attempting to make the UK the go-to place for the research, development, manufacture and production of new electrical storage technologies for both the automotive and the wider relevant sectors.

Accelerated technology development

Building on this general approach, the Royal Academy of Engineering has now established a scheme as part of the UK Government National Productivity Investment Fund, to accelerate the development and commercialisation of other emerging technologies within the UK. This will involve the establishment of 10 new University ‘Chairs in Emerging Technologies’ at UK universities: this scheme will identify research and innovation visionaries and provides them with long-term support to enable them to build a global centre of excellence focused on emerging technologies with high potential to deliver economic and social benefit. This type of public investment has been seen to be highly effective in stimulating co-investment from the private sector, enabling the UK to secure an early foothold in a potentially important future market and preventing UK companies from losing their competitive advantage as other countries get involved.

The UK magazine ‘The Engineer’ explained both the diversity of technologies and disciplines represented among the chairs selected and the breadth of societal challenges and economic opportunities that have motivated the world-leading engineers appointed, as follows:

  • One chair focuses on technologies with strong medical applications. It has the objective to deliver a step change in personalised medicine by engineering cells that can combine precise disease diagnosis with therapeutic intervention in a closed loop circuit – to prevent the disease developing or provide a cure. This is sometimes called ‘theranostics’.
  • Another focuses on reducing the burden of brain disorders. The goal of the chair is to accelerate the translation of therapeutic bioelectronic systems – for example a ‘brain pacemaker’ – from laboratory to industry.

Artificial intelligence, robotics and materials science, AI and robotics also had strong representation among the chairs selected. For example, one chair addresses the technologies underpinning soft robotics, which have the potential to impact upon many areas of our lives, from implantable medical devices that restore function after cancer or stroke, to wearable soft robotics that will keep us mobile in our old age – plus biodegradable robots that can combat pollution and monitor the environment.

Other chairs address issues of safety and reliability associated with AI and robotic systems – a topic of great societal importance and current interest. Two other chairs focus on driving improvements in materials that underpin important industrial and societal applications. One will develop novel interactive technologies using acoustic metamaterials; another is targeted at the optimisation of next generation battery materials for improved cost, performance and durability.

Others of the chairs draw upon recent advances in the physical sciences to address novel areas. They include radical new space technologies that will underpin entirely new satellite applications; an integrated approach to two-dimensional classical and quantum photonics; and a platform for multiscale industrial design, from the level of molecules to machines.

The CET scheme steering group were deeply impressed by the quality of the applications for these chairs that they reviewed, which bodes well for the UK’s ability to continue to be at the leading edge of technology disruption. Nevertheless, it is notoriously difficult to forecast which technologies will turn out to have the most significant impacts over the long term. It would appear that the major problem will be to attract long-term technology investment from UK companies, who are notoriously short term in their views on financial payback and investment decisions.

This article was featured in the June 2018 edition of the journal South African Instrumentation and Control, published by technews.co.za

The European Scene

The German organisation Profibus & Profinet International (PI) publishes annual statistics on the numbers of devices installed with interfaces equipped with their communication technologies, which also include ProfiSafe and IO-Link. The trend towards Profinet increased in 2017, with 4.5 million new nodes installed, an increase of 25% on the previous year figure, which brings the total number installed to 21 million. Possibly because of the rise in Profinet systems, the Profibus DP numbers added seem to have reached a plateau over recent years, with a population of 60 million.

Profibus PA and ProfiSafe node numbers are growing strongly in the process automation field, with the ProfiSafe adoption growing 25% in the year, adding 2m nodes to reach 9 million in total. Similarly IO-Link device numbers installed in the year increased 50%, adding 2.8m to achieve a population of 8.1 million, linking sensors and actuators to a PLC as a subsidiary network below the fieldbus/Profinet level. PI recently published an IO-Link wireless specification, and demonstrated the technology at the Hanover Trade Show earlier this year.

Government Interferences

Legislative rulings have affected businesses and consumers across the EU recently, with the European Union’s General Data Protection Regulation (GDPR) causing avalanches of email asking for a subscriber’s permission to be re-registered with every firm they have ever dealt with, to allow them to record the fact. Even companies from outside the EU will face financial penalties, if they send out emailed newsletters or promotional messages into EU subscribers, without having these permissions confirmed, registered and recorded!

In the USA, the EPA, under the Trump administration, has dropped most of the more Draconian measures that they had originally proposed to impose on chemical plants, after the explosion at West Fertilizers in Texas that killed 15 fire-fighters and injured 260 people. The CSB report on the incident also listed 19 other Texas facilities that store large amounts of Ammonium Nitrate fertiliser, and are located within half a mile of a school, hospital or nursing home. One regulation that will be introduced in Texas is that local fire marshals will inspect all sites storing ammonium nitrate, once a year. Hopefully this might help prevent any further explosions that might result in large off- site consequences.

The changes that were proposed by the EPA and that will not now be introduced include (1) the need to evaluate options for safer technology and procedures that would mitigate hazards; (2) the requirement to conduct a root-cause analysis after a catastrophic chemical release or potential release incident; and (3) performing a third-party compliance audit after an accident at a plant involving the release or potential release of chemicals.

In the UK, Barclays Bank, rather than the Government, is reassuring UK exporters worried about Brexit and trading afterwards, with a survey that shows 39% of International customers would be more inclined to buy a product if it displayed the Union Jack. This was especially true for consumers in Asia and the Middle East (India, 67%; UAE, 62%; China, 61%), and also for younger consumers generally, where nearly half said this would encourage them to make a purchase. For over 55 year olds (who maybe had more life experience) the figure dropped to a quarter. It’s all statistics!)

Research projects

Splitting water into hydrogen and oxygen was first demonstrated by Fujishima and Honda using a titanium dioxide electrode. Since then, scientists have been on the hunt for the ideal material to perform the task, as Hydrogen is a very useful, green fuel for portable power. Now, a team from Exeter University has made a significant hydrogen energy breakthrough, developing an electrode that splits water using only light. The photo-electrode, which is made from nanoparticles of lanthanum, iron and oxygen, absorbs light before initialising electrochemical transformations to extract hydrogen from water. The team is currently working on further improving this material to
make it more efficient, to produce more hydrogen.

At the Drives & Controls Exhibition in the UK this year all the motor manufacturers were showing the condition monitoring capabilities of their offering, usually measured by vibration monitoring sensors. Possibly ABB went one step further, showing a sensor assembly that can be attached to almost any low-voltage motor, existing or on a new project. Transmitting information over Bluetooth, the sensors require no wiring, and are attached directly to the motor’s frame. Within the unit, sensors collect vital data points like vibration, sound and temperature, and upload that information via an ABB gateway or Smartphone to the cloud, where it is analysed. The results are sent back for optimising performance and predictive maintenance, just like a roving maintenance engineer!

This article was written for the July issue of the South African Journal of Instrumentation and Control, published by technews.co.za

Plant control systems and the internet

The following is my personal view of the business planning quandary faced by the major automation companies, first expressed in a Comment page published by Technews.co.za in the South African Journal of Instrumentation and Control, SAIC, March 2018 issue:

It is a common saying that the pace of technology change accelerates with time: although possibly as the observers get older, they become set in their ways, and cannot keep up.

This is certainly true, in my experience: I am getting older, set in my ways, and struggle to keep up. However:

It is not only the pace of such changes, but the speed at which the changes are spread across the ‘world market’, that makes new technologies so rapidly applied and, sometimes, profitable. In consumer markets, the effect is most evident, with the spread of mobile phones and mobile computing: possibly this would all not have come to pass without the availability of the Internet fuelling the spread of information. But for automation, and industrial sensors, has the technology change been rapid? I believe it has, and believe it is now accelerating ever faster, taking advantage of the advances made to meet the demands of other users. This has been evident, and mentioned in these columns, in referring to wireless sensors, batteries for self-powered devices, and self-power from solar or vibration or heat energy. There are many more developments that should be included in that list.

The problem for Automation companies

But how are the major sensor and automation companies driving this growth into their businesses using advances in technology: what are they researching? Where are they investing to get a business advantage? I think that their business planners are having a difficult time at the moment.

Around ten years ago, the big new technology coming to the fore was wireless communication from battery powered sensors. The large automation companies, like Emerson and Honeywell, invested heavily into this technology, and there was the inevitable confrontation between two rival systems – WirelessHart and ISA100. The automation marketplace thrives on such confrontations, for example the spat between Foundation Fieldbus and Profibus. It happens in other markets too; think of Blu-Ray and standard DVDs, PAL and NTSC TV systems etc.

Other perceived growth areas

After the wireless investments blossomed, the Internet was looming, and everyone believed they had to take advantage of the data that could be collected, and networked. Certainly Emerson and ABB went heavily into power network control systems, but ABB had major product availability and systems installation capability in the power industry and has made real progress. Emerson eventually sold out of this network power business, but retains the Ovation DCS used for thermal power station control on site.

Automation companies also bought into the long-established, relatively dormant and slow market of condition monitoring systems, by acquiring the companies quoted to be ‘active’ in the field, who had the ‘black art’ knowledge of industrial condition monitoring. Personal experience, back in the ‘70s, has taught me what a hard sell and difficult market even the simpler condition monitors offer, monitoring bearing wear etc, and that hardly suits the major project potential that might be of interest to big contractors. Complex systems, such as those applied to turbines in power stations, did offer potential, but needed real specialist back-up.

Additionally, the people in the business, such as Schaeffler perhaps (once again the product suppliers with the customer base), slowly developed their own bearing monitoring systems, ranging from portable hand-held units to bigger wired/wireless systems – these are the ones that I believe will succeed in this market. An alternative approach adopted was based on wireless technology developments, which needed a central monitoring system, the ultimate goal for the automation guys. Sensors for steam trap monitoring were designed by majors such as Emerson, to expand their plant control systems into condition monitoring for the plant engineers.

Sure enough, after a slower start, steam trap companies such as Anderson (US) and Spirax Sarco (UK) developed their own systems, and had the market entry with the customers using their traps. The opposite approach was adopted by Yokogawa, which is the pioneer of ISA100 industrial wireless systems. They created alliances with people like Bently Nevada, the bearing condition monitoring sensor people, and with Spirax Sarco on steam traps. Maybe this was to be able to reverse sell them the back-up products and technology for wireless systems, or maybe to hope for the potential of a plant monitoring control system supply.

Software systems

Most of the automation majors have alliances with the large software and computing companies, like Cisco and HP. The current approach seems to be to use these alliances to piggy-back a 24/7 plant monitoring system using the Internet, supplied as a service across the world. Again, I believe the companies with the product on the ground, the stuff that needs monitoring, will be the major players. Here it looks like GE, monitoring its own brands of refrigeration compressors, large pumps and gas turbines at power stations and offshore etc. are best placed.

The future

The quandary is where the Internet will help the industrial control systems and sensor suppliers expand their businesses in the future. The answer deduced above is stick to what you know and what you are known for. The irony is that the major with the best potential now is Rockwell Automation, with its systems based around Ethernet communications, interfacing with anything, plus their onsite Ethernet hardware, with control systems already configured to deal with such varied inputs. Maybe this was why Emerson made an abortive take-over offer for Rockwell late last year. The potential has also been seen by Profibus, who are pushing forwards with their Profinet, and where they go, Siemens will always be in the background.

Process plants as weapons of war

Malware over the Internet has replaced the large gunboat that was despatched in previous times – say 200 years ago – to send a message to the heart of a rival nation, indicating that relationships were becoming a little frosty. Then submarines and ICBMs were introduced, as less vulnerable to counter-attack – and providing hidden strength to be activated when necessary. The same applies to malware, in that once it is in place the weapon can be hidden and dormant until required. However, with any new missile system or weapon, the routing, targeting and performance of the latest versions have to be tested, and often this testing can be observed and monitored.

For any nation or group with an evil intent against another, this gives a major opportunity to cause chaos or damage to the infrastructure or manufacturing operations of a target country. This was seen in 2010 with Stuxnet, the Malware targeted at Siemens controllers in Iranian nuclear centrifuge installations. The source of the virus (officially) was never traced, but it was thought to have been from Israel, possibly with support from the USA. So Iran saw the effectiveness of this approach, and then developed the Shamoon virus, which caused major damage to all networked PCs at Aramco in Saudi Arabia in 2012. A further variant of Shamoon was unleashed in 2016/17, targeting ordinary computer systems around the Persian Gulf, as well as in Saudi Arabia.

Following these events, many cyber-security service businesses and departments appeared, in addition to those which were developing anti-virus systems to protect computers from hacking by fraudsters and criminals. Both of these types of company monitor any new attacks and intrusions, and normally report that state sponsored hacking is known to have originated from Israel, Iran, Russia, USA, and North Korea. Indeed some of the most active hacking has been from a Russian group known as Sandworm, particularly disrupting networks and systems in the Ukraine starting in 2014. Malware called ‘Industroyer’ was used in 2016 to cause a power blackout in Kiev, by modifying the ABB configuration files in the electricity supply grid network systems.

The latest attack

Two such cyber-security service businesses are FireEye and Dragos, based in the USA. In December 2017 they reported on a new attack (actually seen several months before) delivering malware into an un-named petrochemical plant control system in the Middle East. Others have reported this malware was most likely to have been developed in Iran and targeted at a Saudi Arabian installation. The FireEye investigation team from their Mandiant subsidiary found that the plant safety system, a Triconex SIS, had caused an unexpected safety shut-down. Triconex is a company within Schneider Electric, following their acquisition of the Invensys Group: their triple-redundant safety systems protect major hazardous installations such as petrochemical plants. They also are the ultimate shut-down safety system for many nuclear power plants around the World, including most of those in China.

FireEye called the malware they found “Triton” – it is also known as Trisis. The implication of their report was that the Triton attack framework gained remote access to an SIS engineering workstation, sought out the Triconex controllers, and tried to inject new commands into their operations. It seems that the workstation (on site) was in programme mode at this time, hence opening a potential window. There was no indication that the malware used any vulnerability in the Triconex system or its program code. In fact the triple redundant safety system reacted properly: the new single instruction did not pass the built-in validity checks, and so Triconex shut down the plant operations safely, as is the requirement of such a safety system.

FireEye interprets that this attack, which shows persistence, the lack of any clear monetary goal, and the technical resources necessary to create such an attack framework, as suggesting the origin is a well-resourced ‘nation-state’ actor. Either this current attack is reconnaissance development testing of part of what would need to be a significantly expanded multi-point approach to penetrate and control Triconex, or at a minimum it is designed to be economically disruptive to the target plant. Other commentators have suggested that Triton could prevent the Triconex SIS from carrying out its safety function, and drive the plant to destruction. Whilst this is unlikely, and not supported by current knowledge, the malware is undoubtedly aimed at the safety system, and Triconex is the omnipresent safety system used in most of the hazardous plants across all countries, whatever the origin of the plant control system.

A unique ubiquitous target?

Industrial control systems – for petrochemical plants, nuclear and other power stations, water treatment plants, power grids – are standardised across the World, so that they can accept inputs from equipment from many manufacturers: this is good, because there are no monopolies. It is also bad, because anyone can learn how to access these systems. While there are maybe ten major DCS suppliers worldwide, the SIS supplier base is much smaller – there are two or three suppliers. Of these, Triconex is by far the largest supplier, making them a very tempting target for anyone intent on world domination!

This article was written for and first published in my column in the February 2018 issue of the South African journal of Instrumentation and Control, a magazine from www.technews.co.za

SAW technology for Bürkert flowmeter

This review of Surface Acoustic Wave (SAW) techniques was first published in my regular column in the December issue of the journal “South African Instrumentation and Control” (SAIC), published by TechNews.co.za

The SAW (surface acoustic wave) technique offers fascinating opportunities for many different styles of monitoring sensor. The first example seen many years ago really impressed me: it was called TorqSense, a torque measurement sensor applied onto a drive shaft, with no external electrical connections to the shaft needed. This used a SAW device mounted on a quartz substrate: the input and output sensors for the acoustic waves are separated by the length of this substrate, which changes as the quartz is deformed by the torque. Feedback creates a high-Q resonant circuit, and the resonant frequency changes as the quartz is distorted. RF excitation and monitoring of this resonance from an external unit gives a measure of the torque: this has been offered commercially by the UK based Sensor Technology for over 10 years.

Since then SAW techniques and sensors have been studied and researched by many universities, and sensors have resulted that measure temperature, pressure, viscosity, humidity, and even chemical concentrations. The idea is to choose a substrate or acoustic delay-line material between the acoustic transducers that is influenced by the environment to be monitored, such that it is stretched, or the acoustic path length changes in some other way. A recent market status report, by Mordor Intelligence, suggests that the total market for all such SAW sensor systems will be almost $4Bn by 2018.

The clever part in creating a sensor is to modify the acoustic properties of the piezoelectric material between two sensors in some way. Chemical and biochemical sensors for monitoring liquids have been created using a lithium tantalate piezoelectric with a micron thick coating of PMMA or cyanoethyl cellulose, which is sensitive to the chemical target, and keeps the surface waves near the surface, which are therefore influenced by the liquid properties.

Industrial flow applications

After collaborating with such university research for some years, in 2014 Bürkert saw the opportunity to develop a liquid flowmeter using SAW transducers, which could give major advantages particularly in hygienic applications – one of its key market areas. In this case, the SAW transducers were to be used to launch the ultrasonic pulse into the pipe wall of the flowmeter, which then leads to transmission of the signal diagonally across the fluid flow. The pipe wall and the moving liquid create the variable length acoustic delay line between opposing pulsed sensors, and fluid movement creates the change in this delay.

Burkert261_FLOWave_SAW_flow_sensor_pic1_PR2548_58253Effectively, Bürkert was using the SAW transducers as the upstream and downstream sensors for a time of flight type ultrasonic flowmeter. But also there is no intrusion into the flow tube, so the meter is suitable for ultra-pure applications like pharmaceuticals, water for injection and so forth, as well as food and beverage applications.

Development and field testing has covered the last two years, with a careful product release for suitable applications – typically initially used on low conductivity clean liquids, such as water for injection (WFI) in the pharmaceutical sector. Indeed one field test unit was installed in the supply line of a production filling system for infusion bags. Now, the Bürkert FLOWave range of flowmeters, covering DN15 to DN50 pipe sizes, is fully available for sale. This range of sizes covers the smaller bores typical of industrial requirements, in contrast to the larger ultrasonic flowmeters available from other suppliers. FLOWave is designed for hygienic use, and certified to EHEDG and 3A standards. The pipe has hygienic style end connections, and is internally finished to 0,8 or 0,4 microns: it is fully CIP and SIP tolerant, and indeed has been used to control CIP cycles, as the unit also provides a temperature measurement of the flowing liquid. It uses four SAW transducers, two on each side of the sensor pipe section, therefore acting as a dual path flowmeter. Flow measurement performance over the range 1-10 m/sec flow velocity is 0,4% of reading.

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The latest development work has introduced density measurement and an acoustic transmission monitor parameter, which allow indications of the viscosity, bubble and suspended solids content of the liquid. This is useful in CIP process control, and also for monitoring milk in the dairy, during filtration. Bürkert claim an advantage over other styles of flowmeter, in that the unit is small and light in weight when used on a skid. Other applications now being investigated are for wort concentration monitoring in breweries, and homogenisation control in paint manufacture. Highly viscous liquids, such as glue, are also being monitored, where the full bore obstruction-free design is important.