By Dr. Takehiro MORIOKA, International Cooperation Office, NMIJ

It is with profound sadness that we mourn the passing of Dr. IMAI Hidetaka, former Director of the National Research Laboratory of Metrology (NRLM, currently NMIJ/AIST) and former Chairperson of the Asia Pacific Metrology Programme (APMP). Dr. Imai’s immense contributions to the metrology community, particularly his leadership in fostering international cooperation within the Asia-Pacific region, have left an indelible mark that will be remembered for generations.

Dr. Imai served as the Chairperson of APMP from 1999 to 2003, a period of historic transformation for the global metrology community. Following the signing of the CIPM Mutual Recognition Arrangement (CIPM MRA) in 1999, the role of Regional Metrology Organizations (RMOs) became critical. Dr. Imai rose to the challenge, evolving APMP from a community of friendship into a robust, internationally recognized technical organization. By establishing the APMP Secretariat at NMIJ in Japan and overseeing its operation for eight years, he provided the organizational stability necessary to integrate the region into the global MRA framework.

Dr. Imai was a pioneer in introducing the concept of "Uncertainty in Measurement" to Japan and also championed this rigorous scientific approach across APMP. He was instrumental in strengthening the Technical Committees (TCs) and streamlining the processes for Peer Reviews and Key Comparisons. His efforts ensured that the measurement capabilities of NMI members in the Asia-Pacific region reached a level of international credibility that could stand shoulder-to-shoulder with advanced NMIs in other regions.

Beyond his technical and administrative achievements, Dr. Imai was a leader who led with his heart and deeply committed to supporting developing NMIs. At APMP General Assemblies and Technical Committee meetings, he was known for his calm and precise advice. He treated every scientist with equal respect and encouraged a spirit of "growing together." His warm smile, humble demeanor, and ability to bridge cultural divides through the universal language of measurement earned him the lifelong respect of his colleagues across the globe.

Dr. Imai often emphasized that "Metrology is the common language for global trade and scientific progress." Today, the vibrant and collaborative spirit of APMP stands as a living testament to that vision. As we move forward, we commit ourselves to upholding the legacy of excellence and regional solidarity that he so tirelessly built.

Dr. Imai’s international influence extended far beyond regional organizations, reaching the Joint Committee for Guides in Metrology (JCGM). Within this pivotal committee, which is responsible for the revision of the Guide to the Expression of Uncertainty in Measurement (GUM) and the International Vocabulary of Metrology (VIM), he devoted himself to harmonizing theory and practice, serving both as a representative of Japan and as a world-class expert.

We extend our deepest condolences to his family. Dr. Imai’s wisdom, kindness, and leadership will be profoundly missed, but his influence will continue to guide the metrology world for years to come.

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Other heartfelt messages:

As a young metrologist who once had the opportunity to train at NMIJ, I wish to express my heartfelt condolences on the passing of Dr. Hidetaka Imai. I remain deeply grateful for the kindness he extended to me, even as a junior metrologist, and I recognize his important support for  NIMT -Thailand. His generosity, wisdom, and contributions will continue to be remembered with respect and gratitude.

With sincere sympathy,

Rungsiya Sukhon

Metrologist, NIMT