During operation of a fixing bath it is necessary to check the silver content as well as the pH in regular intervals to insure proper operation. A decrease in fixing capacity is noted as an
increase in silver concentration or an alteration of the pH value. The convenient Ag-Fix test strips from MACHEREY-NAGEL allow a simultaneous semi-quantitative determination of silver and the pH value in photographic solutions.

With these strips two paper zones are sealed onto the lower end of a plastic strip, one for the determination of the silver concentration and one for pH measurement. After dipping the test strips in the test solution the colours of the test zones are compared with the colour scale on the container. Ag-Fix comes in packages of 100 test strips. The length of the strips has been chosen for safe and convenient handling.

The plug of the container is filled with a desiccant resulting in a shelf life of 2 1/2 years for Ag-Fix strips.