Is it possible to calculate pH for film developers? How would this be done for the PC TEA formula? TEA is about pH 9.7 diluted the way it is in the recipe, but what does the C do to change this? Is TEA buffering? Or is pH measured?
It has been a long time since college chemistry and I'm not sure they covered this one. Thanks.
my picture blog
ejwoodbury.blogspot.com
The only way I know of to check the PH of a substance is to use
litmus papers or a PH meter.
You can get pH meters all over the place - scientific suppliers, Grainger, the internet,etc. Just don't bother with a dirt cheap one and remember to order a buffer
solutions nearest to your projected working pH, plus a neutral buffer, unless you buy a package which includes them. You also need to keep a little distilled water on hand.
pH can be calculated, but my chemistry is a bit rusty to say the least, so I can't help you here. A trained chemist could easily calculate the pH of a given solution.
I've personally found pH meters to be more trouble than worth for home darkroom use; I now use strips of pH paper. They may not be as accurate as a professional pH meter, but they are cheap, and certainly accurate enough for my needs.
If you're set on getting a pH meter, then get an expensive one and calibrate it daily. Oh, and try not to sneeze or to look at it crossly while using it, or else your measurements could be off.
Quick and dirty results can be gotten with Whatman pH paper. Available at any lab supply. Bob G.
All natural images are analog. But the retina converts them to digital on their way to the brain.
Posting Permissions
Reply With Quote
Bookmarks