Time & Frequency and Electrical & Electronics Metrology Division

CSIR-NPL and ISRO sign MoU for time and frequency traceability services

The main objective of this division is to strengthen and encourage the overall development in the field of science and technology for the country. The main responsibility is the realization, establishment, custody, maintenance, dissemination and upgradation of the national standards for Time & Frequency and Electrical & Electronics parameters.

The Time & Frequency Metrology Section is responsible for the highest level of time and frequency measurements in India using ultraprecise satellite links. In simple words, CSIR-NPL maintains the Indian Standard Time (IST). The time keeping by NPL is based on a bank of Cesium (Cs) atomic clocks and a Hydrogen maser. These clocks are so accurate that they would lose or gain one second in about three lakh years. The traceability of our time scale with BIPM is at the level of few nano-seconds (ns). In addition, we carry out research and development on primary atomic clocks. Our first Cs fountain clock, with an accuracy of a few parts in 10-15, became operational in 2011. A second Cs Fountain is under development (project NOVOCEF). Recently, we have started developing a more accurate clock (≈10-17) at optical wavelengths based on a single trapped Ytterbium ion (project STIOS).

The Division also maintains the primary standards like Josephson Voltage Standards and Quantum Hall Resistance Standards. A dedicated group is working for establishing the Device Fabrication and Characterization for Quantum Metrology.

The Division is also providing various apex level calibration services in Time & Frequency, Electrical and Electronic parameters to the industry & user organizations of the country and provides educational training on industrial metrology to support the economic growth. The various Electrical & Electronic parameters are LF, HF Impedance and DC Metrology, LF, HF Voltage, Current & Microwave Metrology, AC High Voltage & Current Metrology and AC Power & Energy Metrology.


Scientist Incharge Dr. V. N. Ojha
Chief Scientist & Head
Time & Frequency and Electrical & Electronics Metrology Division
Phone: +91-11-45608290 / 45608593
E-mail:  vnojha@nplindia.org
Address Head, Time & Frequency and Electrical & Electronics Metrology Division
Room No. 126
National Physical Laboratory
Dr. K. S. Krishnan Marg
New Delhi – 110012


Sub Division Head E-mail ID
Time and Frequency Metrology Section Dr. V. N. Ojha (Chief Scientist) vnojha@nplindia.org
LF, HF Impedance and DC Metrology Section Mr. Thomas John (Chief Scientist) tjohn@nplindia.org
LF, HF Voltage, Current & Microwave Metrology Section Dr. Anurag Gupta (Principal Scientist) anurag@nplindia.org
AC High Voltage & Current Metrology Section Mr. M. A. Ansari (Principal Scientist) ansari@nplindia.org
AC Power & Energy Metrology Section Mr. J. C. Biswas (Sr Principal Scientist) jcbiswas@nplindia.org
Quantum Nanophotonics Metrology Section Ms. Manju Singh (Principal Scientist) singhm@nplindia.org
Quantum Hall Resistance Metrology Section Dr. H. K. Singh (Principal Scientist) hks65@nplindia.org