Time scale of NPL, known as UTC (NPLI) is being maintained with the help of cesium clock. Judicious frequency off set is introduced time to time. During the last one year, the time scale of NPL has been comparable with other leading timing laboratories of the world (Fig. 2.1). The uncertainty of time scale is maintained at 7.6 ns.

Calibration measurement capabilities (CMC) of time and frequency parameters of NPL have been accepted for entry into Appendix C. These CMCs are now on BIPM website.

NPLI renders calibration service to industry and others customers for stop watch, timer, and frequency counters etc. Frequency sources like crystal oscillators, Rubidium Clock and Cesium clock at NPLI are also calibrated. The performance of many GPS timing receivers is also evaluated by NPLI. NPLI has designed and developed a new stop-calibrator to improve the uncertainty of its calibration. This is under field test.

NPLI continues to disseminate standard time and frequency signals (STFS) via geostationary satellite INSAT with an accuracy of 10 ms.

An innovative time service via telephone line (known as Teleclock service) is in operation by NPL. After successful commissioning this type of service in Nepal and Saudi Arabia, initiation of similar service in SAARC countries are being planned.

NPLI has the recent plan to procure TWSTFT system to establish a link with Asia Pacific region and Europe. Initial study for implementing this experiment has been done.

Development of Laser cooled Cs Fountain clock has been undertaken by NPLI. The overall designs of the optical setup and the physics package have been finalized. The system is in process of integration.