Homebrew PCBs

Ok, so an exterior testing session is warranted and no dangerous operations
must be done while the contraption is on.  I can find a sand pit and put the
contraption in there for failure testing.  I have a van, so transporting my
5500W generator for the electric air compressor is not a problem either.

How can you pull the vacuum down 2 atmospheres?  Assuming I am at 1
atmosphere, isn't 0 a vacuum?  Or did I miss something and you can a bigger
vacuum?  Huh?  How can you go to negative atmosphere?  I thought atmospheres
were mostly used for pressure chambers.

I often see reference to 0-30Hg for vacuum chambers, something about mercury
level.  I figure I'll see where the vacuum dial sits at rest, and where it
goes as air is pumped out is the vacuum side.

Robert
:)




Sound waves can shatter your ear drums. Your heavy layers of  cloth will 
probably not help much here but your ear protectors are a good bet.  While
it is 
true that explosion is worse, implosion carries some of the same  issues.
Stuff 
can fly. Here a heavy blanket is best. The other thing that most  people 
don't think about is shock factor. What are you doing when it blows (Or
sucks in 
this case! 8>)) LOL If you are cutting out a previous mold you could  
seriously cut yourself or others.
PLEASE! I am not trying to scare you! Just be prudent and be  careful! Keep 
the kids out of the way! ALWAYS ALWAYS test out a new device of  this type 
OUTSIDE for the first couple of times! If your going to pull it down 2  
atmospheres normally pull it down to 3 several times as a safety check!  A
failure 
outside is a whole lot safer then inside!
In closing just be safe! I have 3rd degree burns over 33% of  my body from a

stupid mistake 20 years ago that to this day remind me to be  careful!
 
Ray Russell


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