Mr. Chuttipong Tuma, from NIMT, conducted a research visit to the National Metrology Institute of Japan (NMIJ), AIST, from 1–20 June 2025. The visit focused on advancing technical knowledge in AC-DC transfer difference calibration systems, particularly the step-up and step-down calibration procedures and the design of Resistive Voltage Dividers (RVDs) used in high-accuracy electrical metrology.
During the visit, Mr. Tuma studied NMIJ’s primary calibration systems for AC-DC transfer standards and observed how traceability is established across a wide voltage range using step-up and step-down techniques. He also gained practical knowledge of RVD design, compensation methods, and calibration procedures for Thermal Transfer Standards (TTS), which are essential for achieving high-precision AC voltage measurements.
In addition to laboratory activities, technical discussions with NMIJ experts provided valuable insights into the development of national traceability systems and the application of advanced calibration methodologies across low-, medium-, and high-frequency ranges. The visit also highlighted the growing role of Quantum Metrology, including technologies such as Programmable Josephson Voltage Standards (PJVS) and Josephson Arbitrary Waveform Synthesizers (JAWS), in establishing next-generation electrical standards.
The knowledge and experience gained from this research visit will contribute to strengthening NIMT’s capabilities in AC-DC voltage metrology, supporting the development of national primary standards, and enhancing Thailand’s measurement traceability infrastructure. The collaboration also reinforces the long-standing technical partnership between NIMT and NMIJ, promoting future cooperation in electrical metrology research and innovation.
