The FoamScan is used for characterizing foams by sparging a gas (usually N2) through a liquid under controlled conditions. This instrument measures in real time how much foam is formed (foamability) and how fast it disappears (foam stability) once foam generation has stopped. The quantity of liquid trapped in the foam is also measured by means of conductivity. From the measured conductivity the FoamScan can determine automatically the liquid fraction ε in the foam via five electrode pairs along the column (Figure 1).
Furthermore, via a Cell Size Distribution Analysis (CSA) the bubble size, the bubble size distribution, and the bubble size evolution can be determined as function of time. The CSA option includes a CCD-camera (to focus on a square column fitted with four prisms), which can be moved to four positions of the prisms along the column, and a separate light source. Software identifies the distribution of the cell size in an area of about 1 cm2.