I. Dielectric losses at radio frequencies in liquid dielectrics. II. The electrical properties of flames containing salt vapors for high frequency alternating currents. III. The conductivity of flames for rapidly alternating currents
Bryan, Andrew Bonnell
Doctor of Philosophy thesis
Dielectric losses and dielectric constants at radio frequencies for nitrobenzene, water and xylene. The method of resistance variation was used to measure the phase difference psi and dielectric constant K for frequencies between 2 x 105 and 14 x 105 cycles/sec. Special cells were required. (1) Variation with frequency. The results agree approximately with the equations: For carefully dried nitrobenzene at 30°C, psi = .028° + 6.03 x 104/f; for distilled water at 23.5°, psi = 0.8° + 2.09 x 106/ f. These indicate that in addition to the true dielectric loss there is a leakage through the liquid proportional to 1/f. For xylene, psi was too small to measure, less than .01° at 3 x 10 5 cycles. K was found to be practically independent of the frequency, being 2.24 for xylene and of the order of 100 for water. (2) Variation with temperature, for nitrobenzene. K decreased from 42 at 20° to 24 at 14.2°, while psi increased in the same range in the ratio of 7 to 1. These values were obtained, however, for a sample of nitrobenzene for which psi was 12 times as great as for a carefully dried sample.
Physics, Electricity and Magnetism; Physics, Fluid and Plasma