EFFECT OF CONVERGENCE ON DEPOLARISATION MEASUREMENTS IN COLLOID SCATTERING

Abstract

The effect of convergence on the three depolarisation factors p_u P_v and p_h has been investigated in the case of five different colloidal solutions. It is observed that while the values of p_u and p_vincrease with the angle of convergence irrespective of the nature of the colloid, the value of p h decreases with the angle of convergence in those cases where the particle size is very small compared with the wavelength of light,i.e.,corresponding nearly to the case of molecular scattering. For a scattering medium consisting of particles of bigger size, the value of p_h is found to increase with the angle of convergence. The convergence errors of p_u , p_v and p h for a colloid are found to be much larger than those given by Ananthakrishnan's formulw for molecular scattering. The actual values of the errors depend not only on the angle of convergence but also on the nature of the colloidal medium under investigation.