Density Gradient Column Fillers

Density gradient columns are used widely in both industry and research to determine the density of solid samples, especially those that are too small to be measured using pyknometry or hydrostatic weighing. The plastics industry is currently by far the main user of these columns, where they are used to monitor the control of factors such as the degree of polymerisation and the quantity of ‘filler’ being added, however applications are also found in the nuclear industry, biological research and quality control in specialist agriculture.

The accuracy of the column is dependent on a number of factors; the length of the column, the density range that the column spans, and the quality of the calibration. It is also necessary for the liquid in the column to be stable and to have an accurate gradient.

H&D Fitzgerald have developed a micro-processor controlled column filler. This instrument overcomes the problems associated with ‘hand-filling’ columns by replacing the often inaccurate and extremely time consuming methods previously used.

If you are going to use our column filler, why not use our calibrated floats as well?

The H&D Fitzgerald column filler provides:

  • Fast, accurate and consistent building of density gradient columns.
  • Fully automated filling, leaving the technician free to undertake other tasks and duties.
  • Flexibility, as any two miscible liquids can be used to provide the heavy and light densities.
  • Program controlled top and bottom densities, column volumes and buffer volumes.
  • Re-usable gradients, as the previous column setting is stored.
  • Selectable density units, using either g/ml or kg/m³.

Once a column has been built, and a set of H&D calibrated floats has been allowed to equilibrate in it, the instrument can be used to calculate the density of any other object in the column.

The density gradient column filler, used in conjunction with H&D UKAS accredited density floats, will give the user complete confidence in their density measurement.

For ordering information, see ordering Column Fillers.