An Instrument for Direct Measurements of Capacitance and Power Factor

The paper gives the design details of a new type of capacitance meter by which the capacitances and power factors of small condensers (maximum value 0.02 uF) can be directly measured on two calibrated meters, no adjustment or calculation being necessary. The design is based on the principle that when a small condenser (the test capacitor) is connected across the tuned circuit of an oscillator, both its frequency and magnification factor change. The change in frequency is indicated by a frequency discriminator. This gives the value of the added capacitance. The change in magnification factor gives the power factor. By suitable discriminator and computer circuits, the meter readings arc made proportional to capacitances and power factors