Institute of Metrology of Bosnia and Herzegovina

Activities Time-Frequency:

Workforce: 2with: XX permanents, XX non-permanent

SARAJEVO, Bosnia and Herzegovina

The main tasks of the Laboratory for Time and Frequency are the realization and dissemination of the base SI unit for time – the second, operating the national time scale UTC(IMBH) and disseminating official time in Bosnia and Herzegovina. For realizing and disseminating the unit of time, the laboratory operates two high performance cesium atomic clocks, with accuracy of 5·10-13 and long term stability <1·10-14 (5 days averaging period). These clocks are national standards of time and frequency in Bosnia and Herzegovina, and they are involved in realization of international time scale – Coordinated Universal Time (UTC).

The UTC is calculated and maintained by the International Bureau of Weights and Measures (BIPM) as a weighted average of data from atomic clocks kept in about 80 national laboratories worldwide. The result of this comparisson is BIPM Circular T - the monthly publication that provides traceability to Coordinated Universal Time (UTC) for the local realizations UTC(k). The IMBIH TF lab participates in realization of UTC since 2015 and thus achieves international traceability of time and frequency measurements in Bosnia and Herzegovina. National time scale of B&H is kept within ±10 ns respect to UTC. The results are available at

UTC(IMBIH), is available via the Internet from two publicly accessible Network Time Protocol (NTP) servers. For users who need a more reliable service, we offer time dissemination via direct fiber optical and microwave links.

The Laboratory offers calibration services in accordance with BAS EN ISO/IEC 17025 with an internationally recognized calibration certificate with a CIPM MRA (Mutual Recognition Arrangement) logo for calibration of time and frequency counters and sources.
The Laboratory has participated in several international research projects, collaborations and intercomparisons.

The Laboratory participates in reviewed and approved scientific comparisons, operates an appropriate quality management system in accordance with BAS EN ISO/IEC 17025, and has successfully passed peer-review processes (regional and inter-regional). Having successfully completed these steps, the internationally recognized Calibration and Measurement Capabilities (CMCs) of our Laboratory showing the quantities, ranges and corresponding uncertainties are published in 2016 and can be found in the BIPM key comparison database (Appendix C): Here:

Based on these CMCs, we offer calibration services with internationally recognized CIPM MRA logo in the calibration certificates for the following devices:

• secondary time and frequency standards (Cs and Rb atomic clocks , GPS-DO, quartz)

• time interval and frequency counters

• signal generators

• oscilloscopes

• stopwatches

Also, we offer remote calibration of NTP servers.

Coordinated Universal Time as realized at IMBIH, UTC(IMBIH), is available via the Internet from two publicly accessible Network Time Protocol (NTP) servers. The server clocks are directly synchronized by the atomic clocks of IMBIH, they are independent of GNSS (Global Navigation Satellite System) satellite systems and other internet time servers.

NTP server IP addresses: &

We do our best to make one of these time servers accessible at any time. However, we cannot guarantee permanent and disturbance free operation, due to interruptions, congestion and delays on the internet. Also, we offer NTP time dissemination service via direct microwave wireless links.

For users who need a more reliable service, we offer time dissemination via direct fiber optical links. This system is based on White Rabbit Precision Time Protocol (PTP-WR), one of the best performing time transfer techniques, providing accurate (<1 ns), and secure timing traceable UTC. This system is independent of Internet and GPS (Global Positioning System), and use direct fiber optical links to end user. It is suitable for telecommunication operators that meet the recommendations for the timing characteristics of primary reference clocks (ITU-T G.8272), the power-grid sector utilizing smart grids, financial sector needing to comply with EU regulations, time stamp authorities, scientific and other high demanding users.

The Laboratory can organize training from the following area:

Introduction to time and frequency metrology
Establishment and maintenance of national time scale UTC(k)
Calibration of time and frequency counters and sources
Time and frequency distribution over fiber optic links

Expertise :

  • Atomic references
    • Micro-wave clocks and subsystems
      • Thermal beam clocks
  • Synchronisation, frequency transfer and time scales
    • Micro-wave links
      • GNSS
  • Specific methods of time-frequency metrology
    • Noise
      • Short term stability, long term stability
    • Chronometry

Connected Sectors: