Foam analyzer: An instrument based on the foam pressure drop technique

The foam pressure drop technique allows measurement of the characteristic properties of aqueous foams. A new fully automated instrument called the FA1 Foam Analyzer employs this technique. The reduced pressure applied to the measurement cell allows reasonably short experiments even for very stable foams. The technique determines the drainage (water content as a function of time) and lifetime of a foam at an applied reduced pressure. The lifetime as a function of applied reduced pressure depends both on the kind of surfactant stabilizing the foam and the type of liquid films (common thin, common black or Newton black) that built up the foam. We give sample experiments for various surfactant solutions.