Re: Is gage r&r what I want???

can help me out.
> 
> One of the tests that we run is % ammonia.  It involves weighing out a
> sample and placing it under an automatic titrator where a known
> concentration of acid is titrated into the solution to a set endpoint.
>  From what I have read about gage r&r only one instrument is ever used
> for the analysis.  In my case there are obviously two (balance and
> automatic titrator), both of which may be providing its own error into
> the results.

No, Gage R&R is not the tool to use here. Since it is a destructive
test, you cannot calculate the repeatability or reproducibility. You
need to go back to an ANOVA test and measure the variation that way.
The basic principles still apply, however. Identify how much error
there is in the measurements, and then compare that to your sample
specifications.

Good luck. A good reference on how to perform interlaboratory studies
is in The Statistical Analysis of Experimental Data by John Mandel.
Dover press. ISBN 0-486-64666-1.

Jeffrey Stephens
President
Ixian Consulting, Inc.
767 Monte Lane
Jefferson, GA 30549
P:888-900-9813
F:866-226-9188