On 19 Aug 2012, at 21:37, Bob Johnson wrote:
>
> This is why the safety of a product needs to be addressed by a product safety
> engineer, not an auditor. After careful review of the hazards and conditions
> of use, you may end up with a design with either tighter or looser
> constraints than
This is a another example of risks taken to limits beyond the
considerations in the standard tests. The standard is not intended to
contain design rules for every risk, but does a good job of addressing
the common ones. If you are using IEC 60950, then careful application of
chapter 0 is requir
ee.org [mailto:emc-p...@ieee.org] Namens IBM Ken
Verzonden: Thursday, August 16, 2012 8:41 AM
Aan: Doug Powell
CC: John Woodgate; EMC-PSTC@LISTSERV.IEEE.ORG
Onderwerp: Re: [PSES] Ignition sources and exposure time
And also in 950 with the cheesecloth, tissue paper, and wood.
On Wed, Aug 15, 201
And also in 950 with the cheesecloth, tissue paper, and wood.
On Wed, Aug 15, 2012 at 3:20 PM, Doug Powell wrote:
> Conversely, it seems possible to use a "standardized" ignitable
> material to evaluate ignition sources. And this has been done to some
> extent in IEC 610101-1 section 9.2 "Elimi
> From: Doug Powell [mailto:doug...@gmail.com]
> Sent: Wednesday, August 15, 2012 12:20
>
> John,
>
> Your point is well taken.
>
> As a child, I recall running my fingers through a
> candle flame. If
> you move fast enough, you do not absorb "feel" the heat
> of the flame.
In a similar vein to t
In message
,
dated Wed, 15 Aug 2012, Doug Powell writes:
In the end, I suppose my question could be phrased, "Aside from the
rapid and devastating mechanical effects of an explosion, is it
possible or even likely to start a fire with something like UL 94 HB
material, simply with an explosio
John,
Your point is well taken.
As a child, I recall running my fingers through a candle flame. If
you move fast enough, you do not absorb "feel" the heat of the flame.
So it seems to me that the true definition of ignition would be
something like "a cirmstance where a source of ignition is sust
In message
,
dated Wed, 15 Aug 2012, Doug Powell writes:
>For example the UL 94 test is a 30 second exposure to a 50W flame.
>Would a 15 second 100W flame be equivalent?
Sometimes, sometimes not. It depends on what the heat does to the
material. I know of three effects, but there may be more:
Maybe I should have saved this for a Friday question, but here goes.
This is a general question regarding ignition sources and exposure time.
In reviewing the flammability (UL 94) tests and the hot wire ignition
(UL 746) tests, it seems 30 seconds is the magic number for igniting
the sample being
9 matches
Mail list logo
