Discontinuities in concentric-line impedance-measuring apparatus

After describing the essential parts of a concentric-line impedance-measuring apparatus, the author discusses a number of factors which give rise to discontinuities. Three methods of measuring discontinuities in a lossless system are given. It is shown how equivalent networks may be derived to represent non-uniform lengths of line, and how errors in the measurement of unknowns, caused by the presence of discontinuities, may be calculated. In particular, the effect of discontinuities on three types of measurement is described, namely the measurement of resistance and reactance, of conductance and susceptance and of the electrical characteristics of cables. A recommended technique for the measurement of unknowns is given.