Rich, Congratulations on your IEEE Fellow appointment. Do we address you as ‘Sir Richard’ ?
The tablet was probably trioxane solid fuel; typically in a tablet or bar from-factor. See Mil-F-10805. In addition to being used for heating C-rats and MREs, were also used for gas mask training by igniting several bars in sealed chamber, then marching the troops in to subsequently remove their masks to sing our ‘tribal song’. Brian From: Richard Nute [mailto:ri...@ieee.org] Sent: Saturday, May 21, 2016 10:32 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] fire safety test methods for different country standards Hi John: Thanks for your comments. In the end, the “solution” was a different sort of pragmatic approach because the boards were always enclosed in hermetically sealed high pressure (10,000 psi+) / temperature (180C+) -resistant stainless steel tubes which have very little free air volume inside them. That means that there is very little free oxygen for component fires to use, and calculations proved that ignitions involving all the flammable material within the enclosures would exhaust that oxygen well before fires could develop, and also the way the enclosures are built and sealed means that flames or flammable material could not escape unless there had first also been very substantial external physical damage. This is another option. Build a fire inside the equipment and see what happens. I use a fire-starting tablet or pellet (I’ve forgotten the name). An enclosure with minimum openings that would allow replenishment of oxygen will suffocate the fire once the internal oxygen is used up by the fire. The enclosure does not need to be sealed. Usually, such construction will not have very much empty space and therefore relatively little initial oxygen to feed the fire. (I used such testing to prove that a circuit fire would not ignite an HB enclosure.) This is another situation where one can show that a fire will not spread very far beyond the initial fuel. Whether or not this is accepted as compliance with the standard will depend on the certification engineer and the policies of the certification house (and your ability to convince them that the construction is adequate). Rich - ---------------------------------------------------------------- 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 <emc-p...@ieee.org> 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://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <sdoug...@ieee.org> Mike Cantwell <mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher: <j.bac...@ieee.org> David Heald: <dhe...@gmail.com>
