Standards Update

We’re all familiar with the terms ‘intrinsically safe’ and ‘explosion proof’, but what is the difference between the two and what is the most appropriate for your application? Let’s start with the basics. Products destined for use in an explosive area may be intrinsically safe (IS). IS is a protection concept based around limiting the available electrical energy so that sparks cannot occur from a short circuit or failure and cause the ignition of an explosive atmosphere. A typical IS circuit, found in a fixed process control instrument, comprises a permanently located device within the explosive area which, in turn, is protected by a safety barrier located in the safe area. These barriers usually incorporate a series of...

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The EU Machinery Directive may be seen by some as a nuisance but in fact it introduces opportunities for improving both safety and productivity. Up to the end of 2011 machine owners and manufacturers have the choice of complying with the old Machine Safety Directive, based on EN 954-1, or the new one, in compliance with EN ISO 13849-1 or EN (IEC) 62061. And it is almost inevitable that any new legislation has implications for machine producers and end users. For example, some time will have to be devoted to getting to grips with the new legislation and there may even be some small increase in costs. So it’s easy to see why many machine owners are tempted to stick with the old EN 954-1 standard for as long as possible. And they can do...

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Many machine manufacturers may be inadvertently relying on out-of-date standards to demonstrate compliance with the Machinery Directive, warns Laidler Associates, one of the UK’s leading safety and compliance consultants. Only standards harmonised with the current Machinery Directive 2006/42/EC, which can into force at the end of December 2009, can now be used to demonstrate compliance. Many companies, however, are continuing to reference superseded standards that were harmonised with the previous, and now obsolete, Machinery Directive. "In some cases, the changes made to standards to bring them into line with the new Directive are minor," said Paul Laidler, Managing Director of Laidler Associates, "but in other...

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October's general meeting of the IEC in Tel Aviv saw agreement on the new standard for Ex 's' equipment and ongoing work for the transfer of the non-electrical standards work from CEN to IEC. Ron Sinclair was there and reports on these development The requirement to develop a special protection Ex 's' standard came from the IECEx Certification Scheme.  Europeans, using the ATEX Directive, have become used to allowing a degree of initiative in interpretation of standards, since the certification is against the Essential Health and Safety Requirements of the Directive, rather than against the letter of the standard. This is not to say that standards can be ignored, but under ATEX there is latitude available where strict...

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