The precious metal and its various compounds are used in different chemical, photography, lithographic, printing, and block making industries and often used to go-down the refuses in the drain which contains some percent of silver.
It is found that studio workers, Block makers, photographers, do not know the exhaustion point of negative fixers for maximum print permanancy and if they check the quantity of silver present in the solution by our silver estimator paper they will get a good result.
For print fixers- Silver 1gr. per liter is regarded as the limit for maximum print permanency. Discard the fixer if silver touches 1.75gr. per liter.
Negative fixers- Silver 7gms per liter is regarded us the limit. In case of two bath fixers and for second bath 1gr. per liter is for max permanency and do not exceed 1.75gr. per liter.
Our silver estimator paper will ony be used in solution of normal acidity and not in excess acid.