91.  The osmometer is assembled, under a layer of solvent, by clamping two membranes on either side of the glass cell c.

92.  Solvent is then withdrawn from the cell c and a solution of polymer added by means of a syringe.

93.  Results are plotted as against c as described and M n is calculated from the intercept.

94.  As Z is normally concentration dependent, the value at is obtained by plotting against c.

95.  It is defined as where nsimilar and nsimilar o are the refractive indices of the solution and the solvent and c is the concentration.

96.  If the instrument is calibrated with aqueous KCI solutions of known nsimilar a relation, can be obtained where c is the calibration constant.

97.  The molar mass is then related to the excess electron density c of solute over solvent for nm by where R o is the Rayleigh ratio at.

98.  Finally the density c of the crystalline phase is considered to be uniform throughout but different from that of the melt L.

99.  The plot comprises two linear portions meeting at a critical chain length c.

100.  In general c is lower for polar polymers than for non-polar polymers.