1. Science = theoretical; Engineering = empirical 2. Concur with Mr. Nute. Have empirical data indicating hammer test not consistent, and that the steel ball test results are repeatable for similar construction and test condition. 3. There is no reason to deviate from the standard because you are one of the big boys. Unless of course, your employer so big that it effects the local gravitational constant.
Brian -----Original Message----- From: [email protected] [mailto:[email protected]]On Behalf Of Richard Nute Sent: Wednesday, January 09, 2013 10:16 AM To: sudhakar wasnik Cc: EMC-PSTC Subject: Re: Ball drop test and Impact hammer test ... IEC60950-1 2005 and UL, CSA variation Hi Sudakar: No, the tests are not the same because the energy is not the only parameter. One must consider both the impact area and the elasticity of the collision. The ball is 50 mm diameter while the impact hammer is 20 mm diameter. In some cases, the 20 mm sphere will contact a part while the 50 mm will not. The ball is steel while the impact hammer is polyamide, which will affect the elasticity of the collision and therefore the energy imparted to the test object. Furthermore, the impact hammer pre-loads the test object while the ball does not. This rules out a simple drop by a a ball. For most tests, only the energy will affect the results. If you are performing the test for certification, then the test must be done exactly according to the standard. Of course, from a standards point of view, we can discuss whether or not both tests are necessary. Best regards, Rich On 1/8/2013 6:19 PM, sudhakar wasnik wrote: Hi Guys, Can the ball drop test be conducted using impact hammer ? I do not see any credible reason for not using the impact hammer. Impact test using impact hammer delivers x amount of Joules energy upon impact similar to the dropping of steel ball of certain size from certain height. Thanks, Sudhakar Wasnik, MS EE, IES Apple Inc. - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/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]>
