Abstract
To obtain the continuous data for long time of temperature change of standard capacitor, automatic balance bridge with a recorder was constructed. The unbalance voltage from transformer bridge is amplified and separated into two components corresponding to the unbalance of capacitance and conductance. Each component controls toward the balance its motor connceted to a variable capacitor or variable resistor. The amount of its rotating angle is converted by potentiometers into voltage which is recorded together with the voltages from thermocouples by a multichannel recorder.
The temperature of air bath which contains the capacitor to be measured is program-controlled with a period less than 48 hours. Maximum sensitivity of capacitance is 500ppm in 250mm wide recording paper.
Many standard capacitors of 1-0.001μF range were measured. In addition to these temperature coefficients, however, some abnormal changes were clearly found at the same time.
