| Budget Amount *help |
¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
Fiscal Year 2014: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2013: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2012: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
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| Outline of Final Research Achievements |
A new method, ratio-to-phase conversion, was developed for determining the ratio of the voltage to be measured (S) and the nominally constant voltage reference (R). A stepwise signal was generated at the carrier frequency (fc) by cyclic switching R, S and the ground level. This signal is found to be useful because the gain and the offset of the voltmeter can be easily corrected as a two-point calibration. We adopt the phase calculation at fc as the method to realize such calibration. Third order harmonic is found to be useful to eliminate the effect of the time delay of the voltmeter on the phase.
Also, harmonics cancellation in the stepwise signal is proved to be a new method to reduce the non-linearity of the voltmeters.
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