The BIPM data released in September 2018 showed a further increase of NIM time-keeping clocks’ contribution weight to UTC to 7.94%, ranking the third in the world only after USNO of USA and VINIIFTRI of Russia. The UTC scale is adjusted from TAI that is generated by the BIPM based on an international cooperation on UTC. Over 80 time laboratories participate in cooperation and report local UTC to the BIPM.
Recent years have witnessed a continuous improvement in both research and infrastructure and facilities of NIM in the area of time and frequency, with its time-keeping clocks gradually expanded and their contribution to UTC steadily increased. At present, NIM has 10 Hydrogen Masers and 7 Cesium clocks reporting to the BIPM. The deviation between UTC(NIM) and UTC is less than 5ns, an advanced level around the world.