Jim, Here at Emulex we also start at the lowest test level and slowly work our way up. In my time working at a commercial test lab, I have seen several cases where a product could fail ESD testing at 6 kV but pass at 8 kV. We step through all of the levels as required by the test procedure to avoid this "window" effect. In addition, doing the test in this manner allows the test personnel to easily determine the "threshold" of a non-compliant unit. -- Sincerely,
Randall T. Flinders EMC Engineer Emulex Network Systems V: (714) 513-8012 F: (714) 513-8265 [email protected] ______ ______ ______\ /______ ______/ \______ E M U L E X Chairman Orange County Chapter IEEE EMC Society [email protected] ---------- From: Jim Hulbert Sent: Thursday, August 19, 1999 7:07 AM To: [email protected] Subject: EN50082-1:1997 & EN55024 Immunity test standards EN50082-1:1997 and EN 55024 call out the basic standards EN61000-4-2 and EN61000-4-5 for ESD and Surge. EN61000-4-2, Section 5 starts out "The preferential range of test levels for the ESD test is given in table 1. Testing shall also be satisfied at the lower levels given in table 1." EN61000-4-5, Section 5 contains similar wording. This is how we perform our compliance tests. We start at the lowest test voltage levels from the respective tables and step up to the test levels called out in EN50082-1/ EN55024 (or higher, depending on our own in-house product spec.) However, I have noticed that some test labs go straight to the levels called out in EN 50082-1/EN55024 and skip testing at the lower levels. I believe this approach is incorrect because it does not conform to the requirements of the basic standard and is simply not a complete test. As explained in EN61000-4-5, the non-linear current-voltage characteristics of the equipment under test should be considered and the test voltage should therefore be increased by steps up to the test level specified in the product standard or test plan. The same rationale applies to ESD testing where current-voltage characteristics are also non-linear. How do others approach these tests? Are we adding unnecessary test time by starting at lower test voltages and stepping our way up or are the test labs that go straight to the maximum test levels overlooking an important aspect of the testing? Jim Hulbert Senior Engineer-EMC Pitney Bowes --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators). --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
