The performance of an automatic instrument which allows one to measure
discontinously (every 20 minutes) bicarbonate alkalinity (BA) in comp
lex organic solutions is evaluated. Bicarbonate concentration is deter
mined from overpressure measurements in a sealed vessel where inorgani
c carbon is completely converted to carbon dioxide after acidification
of the sample. The accuracy of the instrument has been tested as a fu
nction of various operating parameters (ratio of overhead ps volume in
the vessel over the liquid sample volume, concentration of bicarbonat
es and temperature). Error sources were evaluated and operating condit
ions which yield satisfactory performance identified.