When specifying a process gas analyser and associated sample system, one of the first decisions to make is whether the analysis should be done on a 'wet' basis or a 'dry' basis. While making the measurement on the wet basis will give the true gas concentration, it requires the sample system and analyser cell to operate at a higher temperature in order to avoid problems associated with condensation. On the other hand, to make the analysis on a dry basis - at a lower temperature - requires a sample system that removes the condensates, and the reading for the gas concentration needs to be adjusted to take account of those condensates.
Take note
•Wet or dry? —understanding the pros and cons of both in relation to your application will assist in making the correct choice.
• When considering a new gas analysis system the total stream composition needs careful evaluation.
• To ensure reliable wet or dry measurements be sure to use the correct instrument.

About the author
David Fahle currently holds the position of vice-president of Hydrocarbon Processing at the Servomex Group.
Servomex is locally represented by Elemental Analytics and can be contacted through Robbie Frank (011) 918 6994.

Silicon wafer measurement Improved gas analyser performance The GasBadge Plus Measuring levels of dissolved materials in water On-line analysis of ash content in coal

The quality of the electricity supply has always been a point of major interest. Worldwide there is an increasing concern about power quality, let alone power supply. Social developments tend to increase dependence on a highly reliable electricity supply. On the other hand, developments on the electricity market lead to more competition, reduced costs, accountability for non-delivered energy, less maintenance, environmental aspects, operator safety, better customer orientation and customer satisfaction.

Take note:
• Even switchgear can be environmentally-friendly. • Current trends require a review of our responsibilities to the environment. • Alternative switchgear technologies are becoming available.

#1 About the author
Alex Pikkert has a BSc and currently holds the position of marketing product manager at Eaton Electric B.V. in the Netherlands.
Alex can be contacted on alexpikkert@eaton.com. Eaton is locally represented by CHI Controls and can be contacted through Rob Hare on 011 827 9124 or robh@chicontrol.co.za.

South Africa has been sensitised to the need for efficient motors [1, 2] and this topic is receiving renewed attention. Many of the standards that evolved were used extensively, and lessons were learnt. This article focuses on the new IEC measurement methods.

#1 About the author
Anton Henning currently holds the position of sales manager for low voltage motors at ABB South Africa.
Anton can be contacted on 011 617 2179/anton.henning@za.abb.com.

Take note • IEC 60034-2-1 replaced IEC 60034-2 (1996). • Stray load losses are now to be more accurately estimated – if not directly measured. • The new test methods will show that machines are marginally less efficient than when tested according to the old methods.

Technical and market forces make it increasingly challenging to design wireless systems in a timely and profitable manner. Wireless standards are more complex [1], devices must integrate several wireless standards, and companies are facing increased competition from new entrants to the market. About the author Mike Woodward is the communications industry marketing manager at The MathWorks. He has been active in the communications industry for many years and has degrees in Physics and Semiconductor and Microwave Physics. Mike worked on the transmission infrastructure for the UK’s commercial DAB transmission network, a project that was awarded the British Computer Society’s IT Award for Excellence in 2000. He has also worked on audio processing and has several audio processing patents to his name. The MathWorks is locally represented by Opti-Num Solutions and can be contacted on 011 325 6238 or www.optinum.co.za. Take note • Some current design practices are compounding inefficiencies in the process. • Model-Based Design uses an executable system model as its basis. • Four stages define the Model-Based Design process. • Model-Based Design can offer improved quality, project delivery and lower cost.

Gearbox damage on a press! Faulty batch in cosmetics production! A bottling system produces excessive waste! Who is at fault? Who is going to have to pay for the damages? We are all familiar with the concept of a blackbox as it applies to aviation. The same concept is readily applied to industrial applications. Take note: • A Blackbox is important in an aeroplane—it is equally important at your plant. • A long-term recording of PLC signals is not only a good idea—it should be mandatory. • Blackbox 2 is a complete computer system that monitors your system. • Recorded PLC data is critical information when researching the cause of a fault. #1 About the authors Michael Postelt has his Dpl-Ing (FH) and Joerg Brahms has his Dipl-Oec. Both authors currently hold senior positions at AUTEM, the association for automation software in Emdem. Autem is locally represented by Innomatic and can be contacted on 011 840 0840.

In 1899, Italian inventor Guglielmo Marconi conducted one of the first communications experiments by transmitting an electromagnetic wave almost 50 km across the English Channel from France to England. At the time, his experiment was groundbreaking research that proved the possibility of wireless communications. Ironically, this original experiment would not be successful today. Over the last century, Marconi’s success has contributed to a world where wireless systems are so widespread that interference from other devices would make repetition of his original experiment impossible. Take note: • Multipath propagation of radio signals introduces distortion of the signal. • Proper design of the radio system minimises signal fluctuations. • Testing of receivers is the key to reliable communication. • RF records and play back systems provide a revolutionary approach to receiver testing and design. About the author David Hall is a product manager for RF and communications at National Instruments. He holds a bachelor’s degree in computer engineering from Pennsylvania State University. National Instruments can locally be contacted on 011 805 8197.

Measuring transducer disconnect terminal blocks Sensors for conveying applications New distance sensor 'shines' in all applications Customised magnetic sensors Photoelectric sensors and what they're used for ATEX approved controllers for low liquid flow rates Factor 1 sensors with terminal chamber Leuze sensor for Ex Zones 2 and 22 Endress+Hauser launches Promass S sensor Simulating wireless infrastructures Industrial broadband VPN router Industrial Ethernet Extender makes use of DSL technology

Load management system for prison SABS Design Excellence Award scheme: Call for entries Allpronix awarded Datexel distributorship Yelland Control to change ownership

Altech secures major deal South Ocean Holdings YE results Two pioneers join forces ABB wins major order for energy efficiency technology ABB wins R149 M order from Eskom

Strain gauges are sensing devices that change resistance at their output terminals when stretched or compressed. They are typically bonded to the surface of a solid material to measure its minute dimensional changes when put into compression or tension. Strain gauges and their underlying principles are often used in devices for measuring acceleration, pressure, tension and force. This article reviews their application.

Take note
? Strain gauges produce a fractional change in resistance when stretched or compressed.
? Strain gauges are typically connected in a bridge configuration to maximise output voltage as a function of gauge deformation.
? Strain gauges are commonly used in transducers, load cells or pressure gauges.

#1 About the author
John R Gyorki is from IOtech, based in the Cleveland, Ohio. The company designs and manufactures PC-based data acquisition and measurement instrumentation. Its products are used in a wide variety of test applications, and serve a diverse set of industries including automotive, aerospace, chemical, communication, electronics and many others. Engineers, scientists, and technicians are among the users of IOtech products, in applications ranging from research and product development, to production monitoring and quality control. Iotech is locally represented by Osiris Technical Systems, Stef du Plessis can be contacted at 0851 574747 or stef@osiris.co.za

Enclosed-type dc/dc converters Upmarket protection relay for LV pump motors Protecting your electronic motor with the right relay Efficient speed control for pumps and fans Fluke Norma series optimises power electronics R&D Tectra steals the show Low voltage ac motor protection

If you don’t already have an installed base for Uninterruptible Power Supply (UPS) systems, chances are you’re thinking of installing some. This article argues that, like everything else at your plant, UPSs require preventive maintenance.

Because companies rely on a UPS to deliver continuous power without any disruption to their business, a maintenance plan is a critical component to ensuring that a UPS minimizes the risks of downtime and performs as expected.

Take note:
• UPS systems require preventive maintenance. • In the USA, power failures cost the economy $104 billion per year. • Power failures average 8 hours and 45 minutes per year in the USA, close to the current weekly average for parts of South Africa. • Preventive maintenance schemes can be readily implemented, and replacement cycles established.

About the author
Christelle Larkins currently holds the position of area manager for Eaton Power Quality. The company was established after Eaton Corporation acquired the small systems business of Schneider Electric's MGE UPS Systems. The small systems business in known as MGE Office Protection Systems.

Christelle can be contacted on 011 564 9300 or christellelarkins@eaton.com. MGE Office Protection Systems are also distributed by Comztek and can be obtained by contacting John Middlewick on johnm@comztek.com.

Emergency power supply systems can save lives in hospitals, protect production processes or ensure continuous operation in IT centres and administrative buildings. In the event of a mains failure, the emergency power systems feed the consumers for which continuous operation is vital. The key is a proposed designed circuit breaker to protect, switch and synchronise the generators reliably and safely.

#1 Take note:
? Emergency power supplier a critical system.
? Generators require protection, switching and synchronisation.
? Modern generator breakers must be able to be remotely activated.


About the author
Jose Ruivo as been actively involved in the industry for many years and currently holds the position of sales and marketing director of Moeller Electric in South Africa. Jose can be contacted on ruivo@moeller.co.za.

Never run out of power with Freeplay Lightweight power anywhere Battery tripping units with intelligent charging from Blueginger Battery back-up power supply Crown Publications absorbs load shedding impact with Cummins generator Natural gas generator sets for island mode operation Efficient three-phase UPS