Measurement of very low dielectric losses at radio frequencies

An absolute method is described for the measurement of very low power factors (below 0.0002) to an accuracy of 0.000003 or 4%, whichever is the greater. Modifications to the apparatus of Hartshorn and Ward are described whereby this resolution is achieved. The experimental technique may be used with conventional 53 mm-disc samples or with a liquid-cell-electrode system. Sources and magnitudes of absolute and experimental error are discussed, and fundamental comparisons are made with the Q meter method of power-factor measurement.