Dynamic Foam Analyzer – DFA100

Scientific analysis of liquid foams

Our DFA100 instrument for analyzing foams measures the foamability of liquids and the foam stability based on precise measurements of the foam height. With flexibly deployable modules, it also measures the liquid content of the foam or analyses the foam structure with regard to bubble size and distribution. The DFA100 assists in the optimization of foam-forming products or, in the case of unwanted foam formation, helps with specific foam prevention.

Reproducible, precise and process-related measurements

A particular strength of our DFA100 is the exceptional reproducibility of foam height measurements thanks to an accurately controlled foaming process with electronic gas flow control. The optical sensor measures the quantity of foam produced and the decay characteristic equally precisely and with high resolution, even with very short-lived foams. As a result, the DFA100 is a reliable instrument for analyzing the whole spectrum from slow to very fast decaying foams. Specific measures for avoiding foam can be taken and the quantity and stability of the foam can be optimized with the help of the results obtained.

We have provided options for producing foam by means of bubbles or by stirring, in order to simulate process conditions and to be able to transfer raw data to large-scale situations. As further options, you can also simulate process temperatures up to 90°C or use externally connected gases such as carbon dioxide.

Impressively easy to use

The ease of using the DFA100 when preparing the measurement and when cleaning is of great advantage. The measuring cylinder is simply placed in the instrument using the plug-in unit. The flexible system enables components to be cleaned quickly, and allows one sample to be prepared while another measurement is running. This means more measurements in the same time.

The simple operation of the instrument goes hand-in-hand with the intuitive user guidance of our ADVANCE software. The relevant functions for each particular step are arranged in tiles which display all elements necessary in the context. By avoiding the use of menus and pop-ups, ADVANCE saves any unnecessary clicks and time-consuming searches for hidden elements. Particularly comfortable is the programming of automatic sequences that integrate the software-controlled components of the DFA100 in complete sample analyses with maximum flexibility. Using these automation programs provides high reproducibility and reduces the user’s influence on the results to a minimum.

Tasks and applications

  • Foams for washing and cleaning
  • Firefighting
  • Foams in foodstuffs and body care products
  • Surfactant development
  • Flotation as a method for separating solids
  • Foam-inhibiting and foam-reducing agents (Antifoamers / Defoamers)
  • Foam prevention for paints and varnishes, process and waste water and cooling lubricants

Measuring methods and options

  • Measurement of foamability of liquids and foam decay
  • Determination of total height, foam height and liquid height
  • Foaming by means of bubbles or stirring
  • Investigations of externally produced foams
  • Foamability parameters, including maximum height, foam capacity and foam density
  • Temperature-controlled measurements up to 90°C
  • Foaming with externally connected gases

DFA100 with Foam Structure Module – FSM

Time-dependent analysis of bubble size in liquid foams

The Foam Structure Module – FSM of our Dynamic Foam Analyzer – DFA100 reliably analyzes the size distribution of bubbles of liquid foam and the variation of this distribution with respect to time. The measuring method helps you to quantify and specifically optimize the consistency of a foam based on precise and intelligent video image analysis.

Precise investigation of bubble size and quantity

It depends on the particular product whether foam with large bubbles or with small bubbles is required - for example, small bubbles for shaving foam, and foam with large lamella for a foam bath. Similarly important is the homogeneity of the foam, for example for the sensory perception of a foam delicacy in the mouth. Analyzing the foam structure with our Foam Structure Module – FSM gives the number and size of the bubbles and the size distribution. As a result, the instrument helps to optimize the foam in line with the required properties. To enable different types of foam to be investigated with the same precision, we have provided a system which enables the resolution of the image to be flexibly adjusted. In this way, we enable bubbles which range in size from very small to very large to be easily measured.

Analysis of foam stability based on the time-dependent change in structure

Before a foam collapses, the structure starts to change, wherein large bubbles are formed and smaller ones disappear. Thanks to the high resolution of the timing of the foam structure measurements, this process is accurately recorded and analyzed with the help of the Foam Analysis software. The results help to specifically optimize the composition of a liquid in order to obtain stable or rapidly decaying foam depending on the requirements.

Simultaneous foam height measurement and structural analysis

With our basic instrument, the Dynamic Foam Analyzer – DFA100, a decay curve can be recorded at the same time as the foam structure is analyzed as part of a single measurement. The instrument measures changes in bubble size and quantity in a selectable height range and, at the same time, also the overall decay of the foam. This shows the effect of measures taken to change the foam structure on the foam formation and stability.

Tasks and applications

  • Foams for washing and cleaning
  • Foams in foodstuffs and body care products
  • Surfactant development
  • Flotation as a method for separating solids

Measuring methods and options

  • Measurement of bubble size distribution and the change in this distribution in different resolution ranges
  • Calculation of mean bubble size and standard deviation
  • Output of a histogram for each individual image in the series of measurements

DFA100 with Liquid Content Module – LCM

Analyzing the liquid content of foams

The Liquid Content Module – LCM for our Dynamic Foam Analyzer – DFA100 measures the liquid content of foams and its change with respect to time based on the conductivity. The results provide information on the foam formation and help you to specifically optimize the liquid content and stability of foams.

Fast measurement of foam stability

The first sign that the foam is starting to decay is the discharge of liquid from the foam lamellae (drainage). Accurately measuring the liquid content in the foam as a function of time enables reliable conclusions relating to the stability of slowly decaying foams to be quickly reached. In contrast, when measuring the foam height, it is necessary to wait until the decay is complete before conclusions relating to stability can be drawn. Measuring the liquid content can therefore save measuring time and significantly increase sample throughput.

Accurate moisture analysis at seven height increments

The moisture content is measured simultaneously at up to seven height increments of the foam. This accurate high resolution shows how uniform the foam is and how the homogeneity changes with time. This information is important for the quality of edible foams, for example, which must have the same consistency at every level. In addition, the dense arrangement of conductivity electrodes means that a measurement is always available in the lower region and in the vicinity of the top of the foam. This makes comparative measurements of liquids which foam with different intensity more reliable and makes it easier to specifically optimize the liquid content.

Simultaneous height measurement and analysis of the liquid content

Together with determining the liquid content, the basic instrument can also measure the foam height without reconfiguring. This enables the foam decay curve to be correlated with the investigation of the liquid content. This shows, for example, the effect of measures taken to optimize the liquid content on the foam formation and stability.

Tasks and applications

  • Foams for washing and cleaning
  • Firefighting (moisture-content-dependent extinguishing and propulsion properties)
  • Foams in foodstuffs and body care products
  • Surfactant development
  • Flotation as a method for separating solids

Measuring methods and options

  • Simultaneous measurement of moisture content at up to seven levels
  • Maximum moisture content at every level
  • Half life (time for the liquid content to reduce to one-half) at every level