The impulse voltage standard calibrator is the key equipment for achieving impulse voltage quantity traceability. In order to establish the standard impulse voltage measuring system and realize the impulse voltage magnitude transferring in the China
the calibrator must be developed. The theoretical analysis
uncertainty evaluation and characteristic analysis of a low impendence standard calibrator are described. The calibrator is a small Max generator
the peak value Up
front time T1
and time to half value T2 of the generated impulse are calculated from the calibrated values of the components of the impulse forming network. The operating voltage range of the calibrator is from 10 V to1 000 V and time parameters are: 1.543 9 μs of T1
59.500 5 μs of T2. The expand uncertainty of Up
T1
T2 is 5×10-4
4×10-3
2×10-3 with a coverage factor of 2. The deviation for the peak value of measured value and set value is from-0.8‰ to 0.6‰
for front time T1 from-1.5‰ to 2.5‰ and for time to half value T2 from-1.7‰ to 0.5‰. Repeated 20 times
the max standard deviation is 2.7×10-4. The long-term stability is less than 0.3‰ within a year. Calibrating standard resistance divider that the high voltage arm resistor is 3.45 k?
the impulse scale factor agree with test results of frequency response. The experimental results show that the low impedance calibrator is not only can be used as the primary reference of impulse voltages for calibration of digital record but also can used to calibrating the impulse voltage divider. Compared with Kal1000 produced Strauss Company
the deviation for the peak value of Kal1000 is from-2‰ to 3‰. The experimental results show the high accuracy of standard calibrator.