抄録
The national standard class measuring system with known measurement uncertainties for the lightning impulse voltage in Japan was built in 2004. The values of uncertainties have been reviewed and new methods to evaluate uncertainties have been developed also. One of the new methods is to evaluate uncertainty values by combining the step response waveform and the convolution technique. The other method is by developing a low-voltage calibrator which can directly calibrate the measuring system. In this letter, the outline of the calibrator and evaluated uncertainty are reported on.
