PRINCIPLE

La procedure for the determination of the permanganate value of water, as described in “Standard Methods” has been modified for the automatic monitoring.

The sample is added with sulfuric acid to have exotermic reaction with temperature at 105°C

After white measure, permanganate in sulfuric acid is added, to have oxidation-reduction reaction.

The measure of the reduction in colour of permanganate is related to the permanganate value

The colorimetric procedure is of  inverse type. 

The color intensity is measured at 520 nm