The Ross Miles Foam Analyzer from Krüss GMBH is claimed to be the world’s first instrument for measuring foam height electronically. It uses the ASTM D 1173 standard, which is commonly referred to for investigating the foamability of foam-forming substances. Measurements with the RMFA are, Krüss says, distinguished by high repeatability, large sample throughput and convenient data handling.
For measurements carried out in accordance with ASTM D 1173, the foam-forming solution is presented in a high, cylindrical receiver vessel with standard dimensions. A second quantity of the same solution is introduced from above by means of a likewise standardized reservoir. This passes through the column and forms foam as a result of the turbulence on mixing with the receiving phase. The foam height is measured as soon as the reservoir is empty and also after 60, 180 and 300 seconds. 
 The RMFA integrates the standardized vessels according to ASTM D 1173 in a newly developed measuring device for electronic height measurement. An LED bar and a sensor bar are fitted along the easy-to-insert intake vessel. The foam height is detected based on the difference in brightness at the foam-air boundary – a measuring method which Krüss also uses successfully in its Dynamic Foam Analyzer – DFA100. 
 The electronic height detection ensures considerably improved repeatability of the measurement and, with a resolution of 0.4 mm, achieves a previously unattainable precision. The initial foam height measurement does not have to be manually coordinated with the discharge of the reservoir solution. Instead, it corresponds to the electronically detected time at which the maximum foam height is registered.