Gary My copy of IEC 600068-2-64 has gone walkabout so can't comment on it's content, but the following may help:
Note 15 of 300 019-2-2 observes that most of the energy is <200 Hz and therefore the test profile is descibed with a slope between two frequencies. The shaker will produce frequencies above and below the 5-200 Hz range, but they are not profiled for the purpose of controlling the test. The 300 019-2-0, the introduction to the test methods, suggests a number of reasons for differences between characteristic and test severities, including: - to produce the effect of the environment, rather than reproduce it - allow standard testing to IEC 60068-2-x - different test stresses can induce the same failures. regards Charlie > I'm confused (so what's new) > > I'm looking over some vibration tests from ETSI EN 300-019-2-2 vibration > - public transportation - mechanical tests > > I notice that the Characteristic Severity is quite often wider that the > test severity and the test severity sometimes starts below the > characteristic severity. I'm wondering why, or if I'm misinterpreting > the requirements. > > > > e.g. compare the characteristic severity with the test severity for the > example below. > > > > Type Parameter Characteristic Severity > Test Severity > > Random frequency range 10- 200, 200-2000 > 5-20 20-200 > > > > I quickly checked the tests for the other classifications (Careful > Transportation etc) and none of them require at least the upper > frequency range of 2000Hz. This particular test severity that starts > below the Characteristic Severity. > > > > The base document is IEC 60068-2-64, which I don't have. Is the ETSI a > sub-set of the equipment classes in the IEC document, and the IEC > describes additional classifications that would necessitate the entire > range listed under the Characteristic Severity? > > > > How about the fact that the test severity in this case starts below the > characteristic severity range? > > > - > ---------------------------------------------------------------- > This message is from the IEEE Product Safety Engineering Society > emc-pstc discussion list. Website: http://www.ieee-pses.org/ > > To post a message to the list, send your e-mail to [email protected] > > Instructions: http://listserv.ieee.org/listserv/request/user-guide.html > > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > > Scott Douglas [email protected] > Mike Cantwell [email protected] > > For policy questions, send mail to: > > Jim Bacher: [email protected] > David Heald: [email protected] > > All emc-pstc postings are archived and searchable on the web at: > > http://www.ieeecommunities.org/emc-pstc > - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/listserv/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
