Abstract: An apparatus for metering dusting powder comprises a powder supply container, a stirring mechanism arranged in the supply container, a powder outlet opening at the bottom of the supply container, and an oscillating plate for metered delivery of the powder, which is provided at the outlet opening and to which an oscillatory motion is imparted by means of a shaking device. The stirring mechanism comprises a stirring blade rotating immediately above the bottom and the outlet opening of the supply container, and the oscillating plate of the shaking device executes an inharmonic oscillation consisting of a slow motion to and a quick motion fro.

Abstract: A process for the continuous measurement of the density of a liquid by means of an aerometer body swimming in the liquid is characterized by the feature that the liquid is allowed to flow periodically at an increased flow rate past the aerometer body in order to clean the same of foreign matter, gas bubbles or the like disturbing the measuring, with the measuring procedure being interrupted during this cleaning period. In an apparatus for performing this process, an aerometer body is surrounded in a measuring vessel by a partition wall at a small distance therefrom, and line is provided, through which liquid to be measured may be introduced at a relatively high flow rate into the space between the aerometer body and the partition wall in order to periodically clean the aerometer body.