Abstracts of Technical Articles from Bell System Sources (01 January 1933)

Abstracts of Technical Articles from Bell System Sources Physics, November, 1932. 119 120 BELL SYSTEM TECHNICAL JOURNAL the conversion tables for translating from any system to any other system show the essential equivalence of all five systems. It is recommended that but one system l>e legalized and used generally in place of the five systems, and that this universal system be the coherent meter-kilogram-second-ohm or definitive system. It is further recommended that the international ohm be used in this system. 

This unit is the one actually used in exploring the physical world l>ecause lalwratory resistances for physics and test room resistances for engineering have been so calibrated* Of far greater importance is the fact that by retaining the international ohm it will be simpler, and completely feasible, to eliminate what Heaviside called " that unmitigated nuisance, the 4r factor of the present B.A. units" from our preferred system of units. Compensated Thermionic ElectrometerK. G. COMPTON and H. A compensated single tube electrometer is described and the principles of its operation discussed. 

This apparatus has been found to compare favorably with "balanced t u b e " circuits both as regards stability and sensitivity and to be superior in many respects to the quadrant electrometers which usually have been used for the measurement of small currents, high resistance, or of voltage in circuits of high resistance and in those cases where only an infinitesimal current may be drawn from the source of the electromotive force.