Many program managers, QA engineers and compliance engineers view an “outside” testing arrangement with considerable anxiety. But it doesn’t have to be this way. In fact, using an independent laboratory adds credibility to your product.
With today’s growing demands for more complicated EMC testing, outside testing can benefit your company in several ways, particularly if you are short on in-house equipment or expertise, or a customer or regulatory agency mandates an unbiased third party testing service. So, when it’s your turn to select the best facility for your test needs, these simple, straightforward guidelines can be very helpful (Figure 1).
The first step in selecting an independent EMC laboratory is pure scientific methodology: know the criteria vital to your product’s conformity assessment needs and develop a comprehensive list of available laboratories. You can do this several ways:
· Many testing organizations maintain nationwide directories of testing laboratories divided by testing disciplines. The American Society for Testing and Materials and the American Council of Independent Laboratories are good examples.
· The regulatory agency with whom you are dealing, such as the Federal Communications Commission, often maintains listings of laboratories providing services particular to their regulatory requirements.
· Accreditation bodies also have laboratory directories. The American Association for Laboratory Accreditation and the National Voluntary Laboratory Accreditation Program (NVLAP) of the National Institute for Standards and Technology are examples of internationally known accrediting organizations.
· EMC and test-related trade publications carry a range of advertisements from laboratories illustrating their specific capabilities.
· Trade shows and symposiums, such as the IEEE EMC Symposium, can be excellent sources of information.
Using these sources, develop a list of several laboratories that potentially can provide the testing services you need. Hopefully, they will be in your geographic area.
Many times, however, this is not the case, and this by itself should never be the grounds for eliminating a potential EMC laboratory. You may be spending many thousands of dollars to have this testing performed, so capability and competence should carry vastly more importance and weight than convenience.
Narrowing the Field
Once you develop your list of laboratories, create a uniform request for quotation (RFQ) addressing the testing services you need. If you are not sure of the exact requirements, pick the brains of the technical people at some of the labs you are considering.
Remember, because they offer these services, the laboratories can and should be viewed as professional experts in their fields. Accordingly, they should be able to help you define requirements.
Your RFQ should include as much relevant information as possible. Include a detailed description of the test sample, the test requirements, type of input power, the number of input and interconnecting leads, the modes of operation and criteria for susceptibility.
In addition to the actual testing, clearly define any documentation you may want. List all test procedures, test reports and regulatory documentation, if needed.
When distributing your RFQ, specify a deadline for response from each lab. Five to seven working days from receipt of the RFQ is reasonable. Be wary of any lab that does not respond in the specified time, a clear signal of a less-than-professional organization.
Be wary of verbal quotes; if you receive one, demand a follow-up in writing.
During the quotation period, expect and welcome phone inquiries from the laboratories quoting on the project. Even with defined EMC test methods and requirements and an accurate test-sample description, questions can arise and it is best to resolve them at this point.
Once you receive the quotations, fine-tune your selection process. Dismiss those laboratories that either did not respond or responded late without requesting an extension.
Carefully review the quotations you receive. This is vital. Be sure each quote addresses your exact requirements.
Read the fine print to ensure that nothing has been modified to compensate for a laboratory’s lack of capabilities. An example of this could be unspecified fields or modulations for radiated immunity or susceptibility tests. Dismiss a quotation from a laboratory that varies from the original requirements without a valid explanation.
Finally, look at cost. A laboratory should not be dismissed because of a high price without first questioning the lab. You may be shortchanging yourself.
Pricing structures vary from lab to lab and what appears to be a high price may not be high at all. In fact, it may be a truer price when everything is taken into account, such as downtime and retesting of failures.
Pricing can also be affected by capabilities. Laboratories which carry national and international accreditation, such as the NVLAP military and commercial EMC accreditation, have higher in-house costs. However, accreditations such as these stand behind the test data and reports that you get, and can result in quicker acceptance of your product.
Assign some dollar value when comparing accredited and nonaccredited laboratories. To highlight the issue of cost related to professional services, ask yourself a simple question: If you needed surgery, would you go to the cheapest surgeon with the fewest credentials?
The Final Selection
Reduce your field to two or three laboratories which appear to be competitive and capable of performing your testing requirements. To make your final selection, perform one final important step–a site visit.
Nothing else quite compares with a visit to the two or three labs under consideration. Some labs may hem and haw about a visit, but it is worth the trouble. As a matter of fact, insist on it. Any lab worth its salt will welcome a visit. If a lab does not, view it as a red flag and seriously consider eliminating that lab from the pool.
During your visit, look for several items. First, consider the general appearance of the laboratory. Remember, not only you, but potentially your customer, will witness testing at this location. Look for a neat, clean, well-organized, safe laboratory which will project the image of a professional organization to match your own.
Secondly, thoroughly review all approvals, accreditations and listings that the lab maintains. View items such as NVLAP accreditation, National Association of Radio and Telecommunications Engineers certifications and professional liability insurance certificates as confidence builders, since such programs show that the laboratory has subjected itself to careful reviews and audits by subjective third-party examiners. Review the scope of any accreditation or approval to assure the relevance to your testing program (Figure 2).
Thirdly, review the “building blocks” of a laboratory. Ask about the lab’s QA, calibration and training programs, and find out how each relates to the day-to-day operations of the laboratory.
Make sure they are not just boilerplates. Look for a system of checks and reviews which will assure that your test data is taken correctly and reviewed by the proper professional before being released.
Finally, review the technical aspects of your program. How would the lab approach your testing program? Is there a support room for your support equipment? How would your sample be monitored for immunity? What steps would be taken to isolate the test sample from support equipment?
Working With the Laboratory
After you select a lab, it is important that both you and the lab develop the proper working relationship. All too often, the laboratory and the customer end up in adversarial roles because the test results do not always agree with the customer’s preconceived notions.
Remember, it is the laboratory’s responsibility to report its findings in a clear, timely, accurate and factual manner. The lab should explain both the test results and the method used to obtain those results.
Using an independent EMC laboratory can be beneficial for your organization. It will add another level of confidence in your product and help it gain broader marketplace acceptance.
About the Author
Walter A. Poggi is President of Retlif Testing Laboratories. Mr. Poggi is active in several professional organizations, such as the American Council of Independent Laboratories, where he is Vice Chairman of the Government Relations Committee and the Conformity Assessment Section; The American Electronics Association and the American National Standards Association. He earned a B.S. degree from the New York Institute of Technology. Retlif Testing Laboratories, 795 Marconi Ave., Ronkonkoma, NY 11779, (516) 737-1500.
Copyright 1995 Nelson Publishing Inc.