A high-precision digital readout flow densimeter for liquids

A precision densimeter for liquids, based on the oscillating-tube principle, has been designed. The apparatus allows relative density measurements to be carried out routinely with ppm precision, on 5–7 cm³ of solution, in a total time ranging between 5 to 10 min. The results of various tests reported here show the densimeter to be useful for investigation in aqueous as well as nonaqueous media; it is particularly well adapted to accurate measurements of small density increments, as required in excess-volume studies. Since the instrument operates in the flow regime, it is also adaptable to on-line monitoring of density in continuous processes.