MOISTURE MEASUREMENT BY FT-IR-SPECTROSCOPY

This contribution reports on the use of a FT-IR-spectrometer for measu ring concentrations during the drying of thin films of Polyvinyl aceta te (PVAc) and Methanol. Calibration was carried out by differential we ighing. The spectra were taken in transmission mode while dried air wa s blown over the liquid films. The obtained accuracy was +/- (5% + 0,8 g/m2) for small contents of Methanol and +/- (10% + 2 g/m2) for highe r Methanol contents. The content of PVAc could be measured with 5% acc uracy. The experiments were carried out at room temperature; the exami ned films had a thickness of about 30 to 60 microns when completely dr y.