On Thu, 11 Nov 2010 18:17:16 -0500, "Barry" wrote:

But if you have ever worked with a Fourdriner machine that
is not controlled well, i.e. the thickness varies with time due to any
number of variables,

I have. That and a year's worth of studying paper process chemistry
for precision (sic) measurement of K and Kappa.

When it gets down to what you describe as "not controlled well" that
is more the definition of a Paper Mill that is destined for bankruptcy
before the end of one week - if not a weekend. I've seen the
production floor flood with product when the process encounters a
bottle neck. The production pipeline is enormous with a lot of
intertia.

Measuring a number of sheets achieves sufficient accuracy.

73's
Richard Clark, KB7QHC