The Eskom expansion project will see an increased demand for busbars (not only smelters but any buyer with a demand over 10 000 V such as municipalities, mines etc.) Conductivity is the first consideration in the selection of a suitable busbar material. Various textbooks say that the best conductors of electricity in descending order are: Silver, copper, gold and aluminium. However, only aluminum and copper have economic appeal.

Take note
• Aluminium enjoys a more than four time price advantage over copper for use in busbars.
• Aluminium forms a surface oxide layer which is non-conductive.
• Welded joints are preferable, but bolted joints offer a good, simple, solution.
• Surfaces to be bolted must be cleaned of oxide before jointing, and then sealed to exclude oxygen.
• Serrated washers can be used to rupture the oxide layer, thereby eliminating the need for surface preparation.

About the author
Dr Anthony (Tony) E Paterson holds engineering degrees from the Universities of Witwatersrand, Pretoria and UMIST (Manchester, UK). A professional engineer, he currently holds the position of aluminium specialist at the Aluminium Federation of Southern Africa (AFSA) after having served as executive director for many years.
Dr Paterson can be contacted at tony.paterson@afsa.org.za.

The current state of industrial Ethernet confronts the user with more questions than answers. What do the standards say? What do the association guidelines prescribe? Where can I find a universal solution for all application scenarios?

About the author
Bernd Horrmeyer has his Dipl.Wirt.-Ing and holds a senior position in the Device Connection Technology Division at Phoenix Contact, Blomberg, Germany.
Phoenix Contact can locally by contacted through Sean Hadley on 011 801 8200 or seanh@phoenixcontact.co.za.
Take note
• An industrial Ethernet system must be recognised by the standards and associations.
• The system must be suitable for the environment in which it will operate.
• The installation must be future-proof, accommodating changing technologies.

New M12 Ethernet product line
New LV power cables for mines
Quick electrical installation to IP68
Cold Shrink termination kits from 3M
Patch cable with surge protection

The demands placed on IT systems continue to increase with no end in sight. However, the necessary increases in server performance also come with great increases in heat dissipation. Some companies hardly pay heed to the warning signals and accept the high operating costs and potential system failures. But the ideal solutions are modular rack climate controls built with liquid cooling systems. Compared to conventional double-bottom cooling, these systems are able to combine the seemingly contradictory goals of higher availability with reduced costs. Take note • A single CPU can produce up to 130 W/cm2. • Only 3 to 5 kW per rack can be effectively handled by standard double-bottom cooling systems. • Liquid cooling systems can reliably manage heat dissipation of up to 20 kW per rack. • Modern rack-optimised cooling solutions can be bayed with existing infrastructure, and can expand with a growing system. About the author Ralf Dahmer is the director of product management IT Solutions at Rittal in Herborn. Rittal can locally be contacted via Quintin Lamprecht at 011 609 8294 or qlamprecht@rittal.co.za.

Changes in the core technology of an industry always offer new opportunities for the financial community. A major evolution, triggered by the need for higher recording image quality, is taking place in the video surveillance industry. The financial market has already reacted to it, and the stock value of new-comers has greatly increased in the last three years. This article is an attempt to explain the reasons and consequences of the current technology change in the Closed Circuit Television (CCTV) market. Take note • Video surveillance has become a high-tech industry for good reason. • Digital image processing can be computer resource intensive. • Modern digital systems use network cameras. • Workload is shared between cameras and video management software resulting in far more efficient image data storage. About the author Burg van der Westhuizen obtained his BSc from Potchefstroom University. From 1987 to 1989 he worked as project leader on a number of electronic development programs for military applications. Burg ran his own business from 1989, when he was involved in the following areas: SCADA projects, data acquisition projects and industrial networking. All these involved consulting, system design, manufacturing, installation and commissioning. Burg has been general manager of Industrial Automation and Control (IAC) since 1998. He can be contacted on burg@iacontrol.co.za.

Reliable and flexible solution for mining and minerals sectors
Low-cost control solution for basic applications
Adroit Technologies delivers satellite earth station monitoring solution
GTready, GTset, GTwin
Rockwell signs memorandum with Dassault Systemes
Foundation Fieldbus Device DTM
Osmoz control and signalling range
Measurement and automation technology in one dynamic system

Standard assists designers to improve energy efficiency
Phoenix Contact Technology Fair introduces latest produces to SA market
Aberdare uplifts lives of Graskop school kids
Rockwell hosts Automation University
UPS solution for essential services
RBF rakes in contract after contract
Meissner supplies Sun International

Anglo Platinum and Schneider Electric form strategic partnership
Elquip Solutions expands electrical protection product range
OEN Enterprises gains Land Instruments Agency
Citect earns re-certification under the SCP standards
Spectro's 2 500th instrument goes to Piaggio India
GPRS technology to vend electricity credit
RBF switchgear for Ghana
Lamina distributed by Elquip Solutions

There is an installed base of thousands of medium voltage metal enclosed (withdrawable metal clad) switchgear panels in the South African Electricity Distribution Industry (EDI) and other large users eg the mining industry, Transnet, etc. In many cases, the switchgear may be decades old and due for replacement. This older equipment typically utilises oil as the medium of insulation and interruption, which has historically performed well but deteriorates rapidly when maintenance is not carried out.

Take note
• Much of the installed base of medium voltage switchgear is decades old.
• Lack of skills has led to reduced maintenance and increased risk.
• Retrofitting provides many benefits including increased reliability and reduced costs.

About the author
Morgan Ryan is the general manager: Switchgear at Megatron Federal. He was previously employed as a technology engineering specialist at City Power Johannesburg. Morgan has over 14 years experience in the SA EDI, and remains involved in the industry through participation in various working groups.
Morgan can be contacted on 011 976 3003 or morgan@megatronfederal.com.

Intrinsic safety is a low-energy signalling technique that prevents explosions from occuring by ensuring that the energy transferred to a hazardous area is well below the energy required to initiate an explosion.
The energy levels made available for signalling are small but useable and more than adequate for the majority of instrumentation systems. This is the first in a series of articles reviewing this topic.

About the author Chris Towle graduated with honours in Mechanical Engineering from Kings College, Durham and gained his early industrial experience with George Kent Ltd which he joined as a graduate apprentice in 1950. Progressing through the R&D department, he became Chief Electronics Engineer in 1966. Since 1954 he has been involved in the design of intrinsically safe instrumentation and in British Standards Committees on IS apparatus, systems and codes of practice. He is secretary of both the IEC and CENELEC committees on intrinsic safety. A founder member of Measurement Technology, he was the MTL Group Technology Director for many years, and is internationally recognised for his expertise in the field of ‘explosion protection’. Chris currently acts as consultant MTL. MTL Instruments is locally represented by Extech Safety Systems and can be contacted through Gary Friend 011 791 6000 or garyf@tempcon.co.za.

Safety light curtain with IP67 housing
Portable loadcell tester
Soft starter that controls acceleration
Compact voltage distribution with hybrid terminals
Continuous monitoring of machine operation
New true-RMS multimeter designed for basic electrical tests
New stainless steel encoder line
Modules with pre-applied thermal paste layer
Measurement, analysis and balancing equipment investment by Siemens
Complete range of Exi isolators in compact housing

For many years, ultrasonic sensors have been the standard method for measuring liquids in widely different industrial areas. In the water-supply and distribution sector, they are used primarily in places where—due to the application conditions—a contact-less measurement is preferred. Standing opposed to the reasonable price of ultrasonic sensors are the physical influences on this measuring principle, which, depending on the application, can lead to sizable measurement errors. In this article we compare the two measuring principles, ultrasonics and radar, and the physical processes that influence the measuring result.

Take note
• Level measurement is critical in water management, although required accuracy depends on the application.
• A variety of variables influence the choice of level sensing technology.
• Ultrasonic and radar sensors are so-called ‘running time’ methods, determining the distance from the sensor to the medium surface.
• In many applications, radar technology is successfully displacing ultrasonic devices.

About the author
Jürgen Skowaisa has is Dipl.Ing. and currently holds a senior position in the product management department for ultrasonic and radar at VEGA Grieshaber in Germany.
Vega can locally be contacted through Alan Wynn on 011 958 1901.

A basic control system would normally consist of control valves, actuators, controllers and sensors. All of these terms are generic and each can include many variations and characteristics. With the advance of technology, the dividing line between individual items of equipment and their definitions are becoming less clear. This article will focus, however, on control valves.

Take note
• Various control valves are described and their applications are discussed.
• The control valves reviewed are typically for steam and other industrial fluid applications.
• This article focuses on two-port valves with a follow-up article on three-port valves in a future issue.

About the author
The information used in this article was supplied by Debbie Robbeson from Spirax Sarco. Debbie can be contacted on 011 2300 or info@spiraxsarco.com.

Combined sensor for pump diagnosis and pressure monitoring
Interface adaptor with USB connection
Continuous level measurement over a measuring range of up to 8 m
Expanded radar level program
Process automation specialists of choice