Mercerisation Baume, NaOH Concentration & Barium Activity Number

The per cent NaOH fit is valid from 8 to 32% w/w, which is roughly 11 to 36 degrees Baume, and covers slack through full mercerising; do not extrapolate it to caustic recovery liquors or to the dilute alkali of a scouring bath. Baume readings must be temperature-corrected to the scale reference before conversion - the scale is defined at 60 F and a tank run at 20 C or higher reads low, which understates the true concentration. The barium activity number is a relative measure that depends on the unmercerised control being genuinely comparable cotton; a control of different origin, maturity or preparation history moves the denominator and with it the reported result. Barium activity also cannot distinguish tension-mercerised from slack-mercerised goods, because both convert the lattice - lustre has to be assessed separately.