On the Assessment of New Gaseous Dielectrics for GIS

The assessment of prospective new gaseous dielectrics for GIS is discussed. It is shown that a preliminary assessment of the insulating properties of a new gas can be undertaken from a knowledge of (E/p) and a figure of merit M. These parameters can be obtained from a precision measurement of the linear part of the Paschen curve. A suitable electrode profile is discussed. Measurements of (E/p)lim and M for SF6/N2 mixtures are reported.