The static dielectric constant of methyl chloride to 473 K and 200 MPa

The relative dielectric constant ε of methyl chloride was measured from 303 K to 474 K and from 2.5 to 200 MPa. The high pressure cell and the auxiliary equipment are described. The ε-values vary between 3.47 at 474 K and 17.2 MPa and 11.72 at 304 K and 200 MPa. The accuracy of the measurements is around 1 %. Experimental data at constant temperatures are given by polynomials. In addition, smoothed values are reported. Using the Kirkwood-Fröhlich equation, correlation factors g are determined. The g-values are below unity (1.0 at low density and 0.8 at high density) Approximate calculations with an equation (Patey et al.) based on a hard sphere-dipole-model were performed, which suggest that this model could be successful for CH3CI