A capacitance bridge of wide range and a new inductometer
Albert Campbell · Proceedings of the Physical Society · 1926
A bridge is described by which quick measurements can be made of capacitances covering a range of from 1μμF up to 30μF, the power factor also being indicated. The unknown capacitance C is put in parallel with a resistance P , and the effective self-inductance of the combination, which is approximately equal to - P 2 C , is read on a mutual inductometer forming part of the bridge. By giving P a series of suitable values scale multipliers providing for a very wide range of capacitance are obtained. The inductometer used is of a new type, having a circular scale extending to about 260°, the percentage accuracy of reading being almost constant over the greater part of the range. This novel scale system allows the lower readings to be taken with good accuracy. A small rheostat allows the power loss in the condenser to be balanced, and enables the power factor to be deduced.