What are the major components of an analytical sample cell?

A typical cell has three components: a window assembly, centerpiece and housing.

Analytical cell window assembly with AUCWindow Assembly

  • AUC cells require two window assemblies (top and bottom)
  • Windows can be quartz or sapphire
  • Quartz works well for absorbance measurements and sapphire works better for interference

Centerpiece

  • Standard double sector with AUCEpon (epoxy) centerpieces are most common and can be spun ≤ 42,000 RPM
  • Solid aluminum centerpieces can be spun ≤ 60,000 RPM and require an extra gasket on both sides
  • Higher-concentration samples require a smaller, 3mm centerpiece to allow more light to pass through
  • Two-cell centerpieces can be used for SV and SE measurements
  • Six and eight sector centerpieces are used primarily for sedimentation equilibrium (SE) measurements

Cell Housing

  • This has the same number of fill holes as the centerpiece used, with a key to help line up all parts correctly
  • A typical two-hole assembly might look like this:

Analytical cell assembly with AUCAnalytical cell housing assembly with AUC