The proficiency test defined in ISO/IEC 17043 is an objective means to confirm the reliability of test results conducted by participating laboratories. In high voltage tests, a high voltage laboratory performs the test by using a measuring system of high performance, with an appropriate procedure, correct data processing and so on, to obtain reliable results. By participating in the proficiency test, a laboratory can check the reliability of their test results.
In the proficiency test of high voltage test field provided by JHILL, a participating laboratory performs prescribed high voltage tests within a designated period, and reports the test data to JHILL. JHILL statistically processes the data reported by all the participating laboratories, and reports back each participating laboratory its z-score, which indicates deviation of its test results from the average of all the data of participating laboratories. The names of participating institutions are not disclosed, so it is unable to identify the scores of participating laboratories from the test report.
Participation in the proficiency test provided by JHILL is mandatory to be accredited by the Japan Accreditation Board (JAB), in accordance with ISO/IEC 17025, as a high-voltage testing laboratory.
Participating laboratories shall carry out spark over voltage test of air-gaps under the condition shown in the table below.
series # |
planned year |
categories of high voltage tests |
polarity |
type of electrodes |
gap length d (mm) (underlined lengths are mandatory) |
1 |
2018 |
AC voltage | ― |
rod - plane | 100, 300, 500, 700, 900 |
| rod - rod | 100, 300, 500, 700, 900 | ||||
2 |
2020 |
Lightning impulse voltage | positive |
rod - plane | 200，400，600，800，1000 |
3 |
2022 |
DC voltage | positive |
rod - plane | 100, 200, 300, 400, 500, 750 |
| rod - rod | 100, 200, 300, 400, 500, 750 | ||||
4 |
2024 |
Switching impulse voltage | positive |
rod - plane | 200，400，600，800，1000，1,500 |
5 |
2026 |
AC voltage | ― |
rod - plane | 100，300，500，700，900 |
| rod - rod | 100，300，500，700，900 | ||||
6 |
2028 |
Lightning impulse | negative |
rod - plane | 100，200，300，400，500 |
7 |
2030 |
DC voltage | negative |
rod - plane | 100，150，200，250，300 |
| rod - rod | 100，200，300，400，500，750 | ||||
8 |
2032 |
Switching impulse voltage | positive |
rod - plane | 200，400，600，800，1000，1,500 |
In principle, JHILL hosts the high voltage proficiency test every other year according to the following schedule each time.
September Announcement from JHILL
October Application from participating institutions
November to January (in 3 months) Test at participating laboratories
February Submission of test data to JHILL
March Returning an interim report from JHILL
April Returning a final report from JHILL