I think the first question you have to answer is how old are these
     bags that you are testing.  In a previous life we found that after a
     couple of years that shielding bags would begin to deteriorate due to
     handling and just wear.  I have seen that very often people use
     shielding bags till they fall apart.  You must also look to see how
     many times staples were put through the bag.  (This practice should be
     avoided, because you never want to break the shield on a bag).  If
     nothing else call 3M and ask them.  you may find that the detector is
     made specifically for 3M bags and if you use another brand it may not
     work correctly.


______________________________ Reply Separator _________________________________
Subject: [TECHNET] ESD - shielding bags
Author:  "TechNet Mail Forum." <[log in to unmask]>,                Patrick Ducas
<[log in to unmask]> at _internetcc