METHOD AND APPARATUS FOR MEASURING pH OF WEAKLY ALKALINE SOLUTIONS Russian patent published in 2012 - IPC G01N21/27 

FIELD: chemistry.

SUBSTANCE: pH measuring system has a set of pH detecting elements having many pH indicators. Each indicator has different indicator concentration. The system also has an apparatus for applying said set of detecting elements to a sample solution having known pH. The system also has an apparatus for measuring a first pH response from each of said indicators simultaneously and an apparatus for generating a gauge function representing said first response pH. The system also has an apparatus for applying said set of detecting elements to a weakly alkaline sample solution having an unknown pH and an apparatus for measuring a second pH response from each of said indicators simultaneously. The system also has an apparatus for comparing said second pH response with said gauge fraction to obtain a tentative pH value from each of said indicators and an apparatus for generating an empirical function representing said tentative pH values. The system also has an apparatus for extrapolating said empirical function to zero indicator concentration in order to estimate the actual pH of said unknown sample.

EFFECT: high accuracy of measuring pH of weakly alkaline solutions.

9 cl, 5 dwg