In a message dated 7/18/00 1:13:02 PM EST, [log in to unmask] writes: << Hello all, Could anyone tell me about the advantages and disadvantages between electrodynamic (ED)and repetitive shock (RS) vibration table? What's the guideline for choosing between them? Thanks in advance! Ruby >> Hi Ruby! Go to: http://www.udco.com/reliab.htm There's a really good article that describes the differences between Repetitive Shock and Electrodynamic Shock machines...this article comes from Unholtz Dickie Corporation (a maker of vibration testing equipment). From the article, Repetitive Shock is a very uncontrolled as far as peak G level and spectrum content is concerned. While Electrodynamic Shock contains peak G amplitudes that vary within a moderate, programmable range, and distribution of vibration energy over the test spectrum is uniform. From going to their home page (http://www.udco.com), there's a bunch of links that are very informative concerning vibration. The biggest thing that impressed me with their web site is that they emphasize that one needs to understand what exactly it is that one is trying to accomplish by doing vibration...that means one needs to understand the environment that the product being tested is going to be subjected to, and to what end is the vibration testing being done. A VERY good page if you ask me on the subject of HALT/HASS testing. I'm sure they can help you out with many of your questions. -Steve Gregory- ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################