DECISION METHOD FOR EARTH CAPACITANCE AND LOSS IN MEASURING JIG OF VIBRATOR

摘要

PROBLEM TO BE SOLVED: To obtain a decision method in which an earth capacitance and its loss portion are found with high accuracy, by a method wherein the equivalent element constant and the resonance frequency of a vibrator without a load capacitance are measured, the load capacitance is measured, and the series resonance frequency of the vibrator is measured when a load capacitance element is connected. ;SOLUTION: A load-capacitance mounting part is short-circuited, and a vibrator mounting part is calibrated at three point. A proper vibrator is selected out of vibrators to be measured finally, a standard vibrator is formed, the standard vibrator is connected to the vibrator mounting part, it is measured, and equivalent element constants C₀, C₁, R₁ and a resonance frequency f_s in a series measuring state are found. Then, the vibrator mounting part is short-circuited, and the load-capacitance mounting part is calibrated at three point by using an open/short/load. After that, a load capacitance is attached, and a capacitance C₂ is measured. In addition, the load capacitance is connected to a mounting part, a vibrator to be measured is attached to a measuring terminal, and a series resonance frequency f_s' or a series resonance resistance R₁' is measured. As earth capacitance Cy and its loss portion Ry are found by an expression.;COPYRIGHT: (C)1999,JPO