Testing

Sooner or later, anyone involved with EMI will be involved in troubleshooting an EMI problem, wherever it may surface. Most commonly, the problems will be uncovered during EMI testing, generally very late in the product design cycle, resulting in costly patches and schedule delays. It is best if preliminary EMI testing is done early in the design stage - EMI problems can be uncovered early enough that corrective action can be done in a timely fashion, ideally at the circuit board level. On the back end, EMI problems are often encountered in the field - perhaps because the environment is harsher than that expected by the regulatory agencies or because of an installation problem.

When calibrated test equipment is found in an out-of-tolerance condition, there is additional risk to all products on which it was used. It is important to understand the magnitude of the potential risk because it can lead to dangerous consumer situations and additional business costs.

China is becoming the largest consumer market in the world. Electronic equipment especially high-tech devices are most popular in China. An attractive market, yes, but are you prepared to enter this vast marketplace? Like any country in the world, China has its own regulations for electronic equipment. China Compulsory Certification (CCC) is the most widespread certification you need to overcome.

It is common for every marketed product to contain some type of marking—label, silkscreen, engraving, stamping, or any combination of these four. Every safety standard has a section or clause that is concerned with marking. Among these markings, a label is the one that is commonly used in most products.

Designers and manufacturers of electronic products are frequently faced with the question: “How do I find a high-quality EMC testing laboratory where I can confidently test my products?” The emphasis of the great majority of design and/or manufacturing entities is on obtaining (1) quality preliminary testing of EMC characteristics to refine the design of their products and (2) quality final design testing of their product for regulatory approvals. The final design, of course, is what gets manufactured and released to the general population for their use in daily life. This article is intended to aid designers and manufacturers in finding and utilizing high-quality EMC testing laboratories.

This article describes some of the everyday issues that can arise in a working EMC test laboratory which may affect the quality of the measurements made and illustrates these with real-life examples that demonstrate the importance of robust pre-test verifications. The main focus is on emissions testing, as this is perhaps the area where most problems can occur without being detected. The article also looks at how using various types of reference source during pre-test verifications can help identify those problems and prevent invalid measurements being made.

With the inventions of the transistor in 1948 and the Integrated Circuit in 1958, and the utilization of these major breakthroughs in the development of computers and other electronic devices, industry began to worry about and to design components and end-products that could survive the discharge of electrostatic discharges to chips, printed circuit boards, and final packaged-products.

"A rose by any other name would stink." – Kenneth Adamson

We have all seen advertising copy for test equipment manufacturers’ “EMC receivers” and “EMC test services” provided by commercial EMI test facilities. While we know what the aforementioned receiver does, and what sort of services the test facility supplies, the nomenclature is wrong and is symptomatic of a deeper problem.

Up until now there’s been much emphasis on designing to make a product “idiot proof”. This has provided some benefit, but what Usability Engineering is reminding us is that it is the designers who are sometimes viewed as idiots by the users. It is the users who are the experts (in usability).