Conveyors, Mining, Sensors

Innovation down under: CST and the growth of Australian METS

CST personnel at the installation of A big belt weigher at Cero Verde in Peru. Left to right, Santiago, Nelson, Ian Burrell, Hugh, Dr Vladimir Sin.

Australian METS companies have become world leaders, but does the Australian mining industry know this? Ian Burrell, managing director of Control Systems Technology (CST) explains.

If you’ve worked on an Australian mine, you already know that the Australian mining industry is world leading. We are known for leading the world in safety, efficiency, and quality. 

A big part of that is the technology we develop and produce in this country. From the laboratory to the workshop to on-site installations, our scientists and engineers have the expertise, the decades of experience, and the resources to be the best.

Australian mining equipment, technology, and services (METS) suppliers are in a market-leading position.

Birth of a belt weigher business

In the 1970’s a small Australian startup called Info Belt Weighers (IBW) manufactured a beautiful machine called the Inflo Resometric RF4A. It was mechanically complex but amazingly stable and accurate.

In its short lifespan, IBW quickly sold about 200 units to domestic iron ore and coal miners hungry for the competitive advantage it offered. But, like so many Australian startups at the time, IBW was unable to capitalise on a world-leading technology and folded after just three or four years.

I was fortunate to work for IBW, first in Australia and then in the USA, and in the process, I became strangely bonded with the belt weighing industry. Certainly not love at first site, but when you get to know the field well, it has a certain fascination.

At that time, electronic technology was in its infancy in mining, and it was almost all imported. 

The mining industry needed “industrial instrumentation”, that is, devices for making measurements of temperature, pressure, bin level and of course flow on a conveyor belt. Belt weighers as we call them, also known as belt scales or weightometers. 

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Belt weighers were, and still are, very important equipment in mining. When I started in this business, coal mines in Australia paid a production bonus of as much as $1000 per week. The payment of the bonus depended on the belt weigher’s daily measurement of production. 

The mine owners and the workers both need to have confidence in the ‘bonus belt weigher’ because the numbers they produce are the key to a big-ticket expense and a big-ticket income. There is no middle ground for the belt weigher, it cannot be perceived to be biased in favour of one party more than the other.

Given the importance of the belt weigher and the unreliable nature of Australian businesses at the time, it might be considered strange to put your faith in a young business like Control Systems Technology Pty Ltd. Despite this fact, in 1985 I was privileged to be invited to create a new bonus belt weigher, from scratch, for Clarence Colliery. 

It was a marvellous opportunity and the unit we built, a four idler, four load cell system, became trade certifiable within a few years. Its descendants are still in service today.

The role of trust in innovation

That’s how CST got started, however, like IBW, it could have ended almost as quickly as it began. Thankfully, in the decades since, we’ve learnt a couple of principles which have helped us grow into the trusted partner of miners all over Australia and now the world.

It is relatively easy to develop new technology, but the challenge is to get the equipment into the field where it can demonstrate its prowess and show that it is good value. 

Before even getting to the starting line it is necessary for developers and companies to be trusted, otherwise why would a customer try a new a new product in a critical application like a bonus belt weigher. Trust works in the zone of character, competence, and capability – and this can be an elusive mix.

It’s great to be trusted to provide important equipment, but then you actually have to deliver. 

For CST, integrity means doing what we say we’ll do, and it’s important to us. 

We’ve gone to a lot of effort to keep our word over the life of the business. Sufficient to say that there would never have been an opportunity to build a bonus belt weigher at Clarence Colliery if the electrical engineer at the time, Malcolm Hewitt, had not been able to trust me.

A lot has changed since CST got started, both in terms of technology, and in the makeup of the Australian manufacturing sector. The METS sector is now recognised as one of the pillars of our economy. 

It’s only natural that Australia, a world leader in mining, should also develop and manufacture the technology that supports our miners and that they should be as good as any in the world.

The quality difference

Anyone who has read the classic, Zen and the Art of Motorcycle Maintenance, by Pirsig will know that he had a lot to say about quality. He maintained that quality was something which we all understood but that it could not be defined. Instinctively, this did not seem to be right to me. I thought it should be possible to come up with a working definition. Every manufacturer seems to make products of the ‘high quality’. It is such a cliché these days, but I have a working definition: to me quality is ‘the total content of applied knowledge’ in a product or service. 

For a manufacturer that means having both the intention, and the knowledge, to build a quality product. The manufacturer must have the intention of applying their knowledge to the customers’ needs. The ironic part of this might be that when it comes to belt weighers, customers don’t always understand the quality content.


Setting up a business is a risk and a responsibility. Many people’s lives are influenced: customers, employees and suppliers. A personal objective of mine is that all those involved have a good experience, and with competing interests, that can be tough to achieve. As founder of CST, it is important to me that I be true to my core values. This is expressed in one of our first slogans which was, ‘no customer would ever be sorry that they purchased equipment from CST’. That’s not to say that problems do not occur, of course they do, but it is no good being fearful in business, fear can lead to wanting to cover up mistakes to save money and to not admitting if there has been a screwup. It’s a tough thing to do, but brutal honesty is in my opinion, always the best policy. But doing a good job is paramount and that creates the intention to provide a high-quality experience for the customer.


We defined quality as “the total content of applied knowledge”, but where does this knowledge come from? 

This is where the huge divide between companies who supposedly do the same thing emerges, it’s called their intellectual property (IP). 

Some IP is public domain, some is patent-protected, some is secret. But this so-called IP can also include preconceived ideas of doubtful origin. Much ‘knowledge’ is locked in industry folk lore and is not scientific or good practice.

The best example of this is in accuracy claims. For instance, you may have heard that a four idler scale is 0.25 per cent accurate; or from other manufacturers who claim to have better technology, the ideas that 1 single idler system is 0.5 per cent accurate, a pair of single idlers is 0.25 per cent accurate, and three together is a 0.1 per cent system. 

When I see machines touted under these specifications, I think that belt weighing must be the only field of endeavour where manufacturer can make any claim they like. Big brands make claims that are completely unsupported by science or customer experience. 

When the equipment does not work as expected they are told that the equipment is fine, but that their conveyor, or their application is to blame. The supplier is not taking responsibility. 

I can cite an example of how lack of knowledge caused a big problem at a major iron ore mine in WA. 

It was a case where single idler modular belt weighers were sold as the latest technology and as 0.5 per cent accurate. Plant balance was out, and the weighers were not performing as promised. Before they were declared a failure, they were being calibrated weekly. 

CST’s equipment was much bigger and stronger, apparently a bit ‘old fashioned’ mechanically, but stable. Longer, stronger weigh frames are more stable but even they must be designed to suit conveyor conditions. This is no way to win a job on price but is the best way to have problem-free belt weighing.

The integrity difference

Integrity can be defined as ‘doing what you say you will do’. When thinking about integrity, it is necessary to distinguish between a short-term and a long-term view. In the short term, admitting to a mistake or quality failure may be financially costly, but in the long term, ignoring a problem or lying to a customer is much more costly because it damages reputation and your brand. 

To set the necessary tone of integrity, everyone at CST is required to be a truth teller when it comes to customers, fellow employees and suppliers. It’s a matter of internal consistency, and ethical congruence. A company should never lie to a customer, it is disrespectful and anyway, the customer knows when they are being given the runaround.

Systematic error, the error that is always there

Let’s talk about systematic belt weigher error, the error which is always there. A customer might buy a 0.5 per cent belt scale only to find after a few months of operation that it really has an error of several percent. The confusing thing is that when the weigh frame is checked with static masses or a calibration chain, it looks all right, calibration is within 0.5 per cent or even 0.1 per cent, but the problem persists. 

The sad truth is that most belt weighers have a bias error of between 1 per cent and 3 per cent even though the unit is supposed to be a ‘0.25 per cent’ weigher. This consistent error can be due to a poor weigh frame design, poor alignment, or most likely a bad tachometer system. This error will often change every time the belt weigher is ‘maintained’. This changing systematic error is known as ‘random walk’. It is shocking to consider that such a large systematic error might be present in a piece of equipment presented as highly accurate. Unfortunately, it is very hard to check belt scales. Worse still, if the belt weigher is proven to be at fault, the supplier may come up with a plausible excuse.

Driving home a useful point here, when it comes to trying to solve belt weighing errors, most maintenance departments concentrate on the weigh frame part of the belt weigher, but errors from the weigh length and the tachometer are actually much bigger. So there is a lot of wasted effort in putting weights and chains on and off weigh frames and the very real and fixable errors from the weigh length and tachometer parts of the system are left untouched.

Systematic error from the tachometer, cured

To cure the tachometer issue, CST has developed a continuous tachometer monitoring and calibration system that will keep tachometer calibration perfect all the time. We have determined that actual systematic tachometer error of 0.5 per cent to 2.0 per cent is quite common so it is well worth fixing. These errors originate from belt stretch and the fact that the radius of turning of many tachometer types vary with belt loading. One thing about the automatic tachometer calibration system is that it reveals how stable the tachometer is because it logs all the results. Ignorance is usually bliss. When you monitor something properly with a data logger, a lot can be learnt, and sometimes it’s something you did not want to know.

Research into systematic error in belt weighers

We have a strong R&D department with some very talented people including two doctorates, one in artificial intelligence and the other in belt weighing. CST is committed to research into systematic error in belt weighing. We are conducting both theoretical and practical research into the accuracy of belt weighers, and we have built a comprehensive test rig which can conduct live material tests at 180 tonnes per hour. The rig can handle and re-circulate a test load of 3.6 tonnes. We’re able to measure to 0.1 per cent accuracy at OIML Class 0.2 standards, using a static scale working as a Control Instrument. The test rig supports a research program for a higher degree qualification at the University of Newcastle.

The comprehensive test rig also supports CST’s research and development activities. 

I am very proud of our research and development team, and we are continually working on new developments. 

Dual redundant belt weighers and other developments

Our recently Class 0.2 certified controller unit can manage two independent belt scales and this unit has become the heart of a new model designated the ‘symmetrical, dual redundant’ (SDR) belt scale, or SDR. 

The rig is fitted with one of CST’s innovative weigh frame designs known as the close spaced roller rack (CSRR). This system provides additional support under the belt between main idler sets so there is less belt sag and less belt influence on the weighing result. 

The CSRR can be combined with our SDR belt scale. 

When a customer requires a 0.25 per cent or 0.1 per cent belt scale, CST can offer the SDR system: two belt scales in one, giving dual redundancy and the same accuracy in the same conveyor space which would normally be occupied by one belt scale. We split the standard four idler, four load cell weigh frame into two parts, and add four more load cells. 

The SDR systems is completely self-checking. Agreement between the two halves is evidence of a good installation, good calibration, and good ongoing accuracy. This system also has the virtue of being OIML R50 pattern approved as a Class 0.2 belt weigher for trade purposes.

The IntelliRoll development

Another development at CST is the belt weigher inside a roller, the IntelliRoll. This device is a complete belt weighing system in a roller.

It has energy harvesting to power its operation, load cells, tachometer, microprocessor, WiFi and Bluetooth, and is operated from an iPhone or Android application. 

The roll is durable, sealed to survive in wet and difficult conditions, and can be mesh networked together to operate as a single ‘multi-idler’ belt scale.


CST remains committed to belt weighing and there are plenty of interesting challenges yet in creating good belt weighers that are a pleasure to own. We are continually developing new features, new software, and new products. CST is also looking more to world markets where our knowledge and products are sought after by customers who need reliable belt weighing equipment.

The Australian METS community is growing although industry organisations like Austmine provides a very supportive environment for international growth. 

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