Introduction: Recently, the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China issued an announcement on 10 national metrological technical regulations, including JJG146-2011 "Estimated Blocks".

According to the relevant provisions of the "Law of the People's Republic of China on Measurement Law", the approval of 10 national metrological and technical regulations such as JJG146-2011 "Estimated Blocks" is now being implemented.