Hi, I think we may be talking about different things with "silver estimating paper." I am talking about a (former?) Kodak product named "Kodak Silver Estimating Paper." It is intended to be dipped into either fixer or bleach-fix, then rinsed off and compared to a color chart on the package. It is a rough guide, where one can say "it looks like my fixer is running about 3 or 4 g/l silver," for example.
Originally Posted by Photo Engineer
I don't question that tests on the final processed material are the ultimate arbiter. But for any kind of volume, I think it's better to set up a process with certain aim points. Once you verify that results are ok, then simply keeping the process nailed down should mean that all of the product is ok.
My experience with "pollution" is not as in R&D, but rather an end user of, for example, methods designed by Kodak researchers, who then published papers, which were then the basis of equipment constructed by people such as CPAC. Anything that was published by SPSE or IS&T in the heyday of effluent control, we considered as an option. I was in a position to be part of a group which could evaluate these systems, justify them, then oversee installation and operation. There were always shakeout problems, partly because the scale was much larger than the researcher's pilot tests (things don't always scale up so well).
ps: I probably agree with you on most things (that I know something about), but just don't come out and say that I agree. So you only hear from me when I disagree.