CIPM MRA COMPARISON REPORTS
APMP.T-K4.2
Realization of the aluminium freezing-point temperature
Published on 20/02/2026 - © 2026 P. Saunders et al
Citation P. Saunders et al 2026 CIPM MRA Comparison reports
Authors
Peter Saunders Measurement Standards Laboratory (MSL) New Zealand 
Emile Webster Measurement Standards Laboratory (MSL) New Zealand
Inseok Yang Korea Research Institute of Standards and Science (KRISS) Korea, Republic of
Wukchul Joung Korea Research Institute of Standards and Science (KRISS) Korea, Republic of
Jianping Sun National Institute of Metrology (NIM) China
Julian C. P. Cheung Standards and Calibration Laboratory (SCL) Hong Kong, China
Nurulaini Binti MD Ali Department of Chemistry Malaysia (KIMIA) Malaysia
Efrem Ejigu iThemba Laboratory for Accelerator-Based Sciences (iThemba LABS) South Africa
Charuayrat Yaokulbodee National Institute of Metrology (Thailand) (NIMT) Thailand
Panatda Panpech National Institute of Metrology (Thailand) (NIMT) Thailand
Aditya Achmadi National Measurement Standard - National Standardization Agency of Indonesia (SNSU-BSN) Indonesia
Suherlan D. Sudayat National Measurement Standard - National Standardization Agency of Indonesia (SNSU-BSN) Indonesia
Shaochun Ye National Metrology Centre, Agency for Science, Technology and Research (NMC, A*STAR) Singapore
Abstract
This comparison was designed to compare the realizations of the aluminum freezing point (Al FP, 660.323 °C) of the national metrology institutes (NMIs) in the Asia Pacific Metrology Programme (APMP), and to provide a linkage to the key comparison reference value (KCRV) of the CCT-K4 [1]. The first APMP follow-up comparison of CCT-K4 was APMP.T-K4 [2], in which the realization of the aluminum and silver freezing points were compared, and KRISS and NMIJ provided the link to the KCRV of the CCT-K4. However, it was able to only provide a link to the CCT-K4 KCRV at the Al FP, not at the silver freezing point (Ag FP). While an attempt to provide the link at the Ag FP is still ongoing, there were some requests from APMP NMIs to provide bilateral comparisons for the Al FP realizations. Combining these requests, the APMP have initiated another follow-up comparison of the CCT-K4, aiming to provide links to the KCRV of CCT-K4 at Al FP. KRISS piloted this comparison (APMP.T-K4.2) with National Institute of Metrology (NIM, China) as an additional linking laboratory to the CCT-K4.
The measurements for the comparison were made between 2018 and 2020. Measurements at KRISS were made between January and August of 2019, and the measurements by the other participants were made before and after the KRISS measurements within the period between 2018 and 2020.
The measurements for the comparison were made between 2018 and 2020. Measurements at KRISS were made between January and August of 2019, and the measurements by the other participants were made before and after the KRISS measurements within the period between 2018 and 2020.