Validation of a novel in situ weighing system during vacuum drying

In the presented article, an in situ weighing system for the measurement of drying rate and residual water content during vacuum drying was tested and validated with offline analyses. The influence of buoyancy effects was studied both experimentally and theoretically in terms of sample volume and final pressure. Furthermore, the effect of time drifts on the measured drying rate and residual water content were studied and the measurement errors were quantified for the drying of sorbitol solutions. It was shown that the drying rate and thus residual water content could be determined with good accuracy with the present measurement system.