The Module PA4550 for the Dynamic Foam Analyzer DFA100 measures the liquid content of foam via its conductivity in parallel at seven different heights of the foam column, so that drainage is followed as a function of time and height. Foam generation is reproducible by means of a controlled flow of gas through a frit. The software records independent measurement curves for each electrode and gives a maximum moisture content as a percentage, together with the half-life for each measuring height. The speed and extent of the drainage normally allows conclusions to be drawn about the stability of the foam in relation to other samples. — Krüss GmbH, Hamburg, Germany