{"id":2860,"date":"2022-12-20T13:45:50","date_gmt":"2022-12-20T11:45:50","guid":{"rendered":"https:\/\/www.vsl.nl\/time-and-frequency\/"},"modified":"2026-07-16T14:05:01","modified_gmt":"2026-07-16T12:05:01","slug":"time-and-frequency","status":"publish","type":"page","link":"https:\/\/www.vsl.nl\/en\/areas-of-expertise\/time-and-frequency\/","title":{"rendered":"Time and frequency"},"content":{"rendered":"

[vc_section full_width=”stretch_row” content_placement=”middle” css=”.vc_custom_1668958840727{background-image: url(https:\/\/www.vsl.nl\/wp-content\/uploads\/2022\/11\/Lab-Foto-WEB-36.jpg?id=2232) !important;background-position: center !important;background-repeat: no-repeat !important;background-size: cover !important;}” el_class=”main_header gradient_header dg-position-realtive”][vc_row equal_height=”yes” content_placement=”middle” el_class=”dg-header–small”][vc_column width=”2\/3″ el_class=”dg-padding-none”][vc_column_text css=”.vc_custom_1751637618180{margin-bottom: 0px !important;padding-bottom: 0px !important;}” el_class=”text-white”]<\/p>\n

Metrology for Time and Frequency<\/h1>\n

The second is one of the fundamental units of measurement and very important in measurement results, but just as important is the use of universal coordinated time (UTC), which allows people and systems to work together.<\/p>\n

Innovation also requires improvement in the metrology of time, VSL is therefore involved in the development of an optical clock and has a very long history in the validation of technologies such as white rabbit, for accurate time distribution.[\/vc_column_text][\/vc_column][vc_column width=”1\/3″][\/vc_column][\/vc_row][\/vc_section][vc_section full_width=”stretch_row” disable_element=”yes” el_class=”brand_element_small dg-padding-small” css=”.vc_custom_1668430282165{background-color: #fafafa !important;}”][vc_row][vc_column el_class=”dg-padding-none”][vc_btn title=”Introduction” style=”flat” shape=”square” size=”sm” css=”.vc_custom_1666611255704{margin-bottom: 0px !important;border-radius: 5px !important;}” el_class=”page_btn page_btn_active” link=”url:http%3A%2F%2Fwww.vsl.nl%2Fvakgebieden%2Ftijd-frequentie%2F|title:Introductie%20tijd-frequentie|”][vc_btn title=”Maatwerk” style=”flat” shape=”square” size=”sm” css=”.vc_custom_1666338347652{margin-bottom: 0px !important;margin-left: 25px !important;border-radius: 5px !important;}” el_class=”page_btn” link=”url:http%3A%2F%2Fwww.vsl.nl%2Fvakgebieden%2Ftijd-frequentie%2Fmaatwerk|title:Maatwerk|”][vc_btn title=”Calibration” style=”flat” shape=”square” size=”sm” css=”.vc_custom_1666338430804{margin-bottom: 0px !important;margin-left: 25px !important;border-radius: 5px !important;}” el_class=”page_btn” link=”url:https%3A%2F%2Fwww.vsl.nl%2Fvakgebieden%2Ftijd-frequentie%2Fkalibratie|title:Kalibratie%20tijd-frequentie|”][vc_btn title=”Proficiency Testing” style=”flat” shape=”square” size=”sm” css=”.vc_custom_1666338453060{margin-bottom: 0px !important;margin-left: 25px !important;border-radius: 5px !important;}” el_class=”page_btn” link=”url:https%3A%2F%2Fwww.vsl.nl%2Fvakgebieden%2Ftijd-frequentie%2Fringvergelijkingen|title:Ringvergelijkingen%20tijd-frequentie|”][vc_btn title=”Training” style=”flat” shape=”square” size=”sm” css=”.vc_custom_1666611250033{margin-bottom: 0px !important;margin-left: 25px !important;border-radius: 5px !important;}” el_class=”page_btn” link=”url:https%3A%2F%2Fwww.vsl.nl%2Fvakgebieden%2Ftijd-frequentie%2Ftraining|title:Training%20tijd-frequentie|”][vc_btn title=”VSL Certification” style=”flat” shape=”square” size=”sm” css=”.vc_custom_1666364014026{margin-bottom: 0px !important;margin-left: 25px !important;border-radius: 5px !important;}” el_class=”page_btn” link=”url:https%3A%2F%2Fwww.vsl.nl%2Fvakgebieden%2Ftijd-frequentie%2Fvsl-certificeringen%2F|title:Training%20tijd-frequentie|”][\/vc_column][\/vc_row][\/vc_section][vc_section el_class=”dg-padding-mid brand_element_small”][vc_row][vc_column width=”2\/3″ el_class=”full_width_responsive dg-padding-none”][vc_column_text css=”.vc_custom_1751637704915{padding-right: 10% !important;}”]<\/p>\n

Calibrations<\/h2>\n

VSL provides the most accurate calibrations in terms of time and frequency that can be traced directly back to the national time standard. The scope of VSL ranges from frequency measurements with an uncertainty of 0.000 000 000 000 2 Hz\/Hz to stopwatch calibrations with an uncertainty of 0.014 seconds per day. <\/p>\n

VSL supports its clients in the management of time-dependent measurement data with various calibration facilities. By calibrating frequency standards, atomic clocks and speedometers, for example, we offer traceability to the second and UTC(VSL). <\/p>\n

VSL has steered the development of Two Way Satellite Time and Frequency Transfer (TWSTFT) in the 1980s. This method is the most accurate check done between UTC contributions around the world. VSL, in collaboration with a technology partner, has also taken on the task of calibrating European contributions to UTC using this technology.[\/vc_column_text][\/vc_column][vc_column width=”1\/3″ css=”.vc_custom_1757065231871{margin-top: 0px !important;margin-right: 0px !important;margin-bottom: 0px !important;margin-left: 0px !important;padding-top: 0px !important;padding-right: 0px !important;padding-left: 0px !important;}” el_class=”full_width_responsive tablet_expert”]

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Meer weten over onze diensten? <\/strong><\/h3>\n

Onze experts staan voor je klaar.<\/p>\n\n\t\t<\/div>\n\t<\/div>\n\n\t

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Michael van Schaik<\/b>
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\n\t\t\t<\/i> vsl@vsl.nl<\/a>\n\t\t<\/div>\n\t<\/div>\n<\/div><\/div><\/div><\/div><\/div><\/div><\/div><\/div><\/section><\/div>[\/vc_column][\/vc_row][vc_row el_class=”dg-index-fix dg-padding-small-top”][vc_column width=”5\/6″ el_class=”dg-padding-none full_width_responsive”][vc_column_text css=””]<\/p>\n

Time Service Bulletin<\/h2>\n

VSL provides a periodic time service bulletin. This weekly report with information about the time and phase difference with the national time standard UTC of signals has been measured, allows you to manage your atomic clock to keep track of your internal time standard.[\/vc_column_text][\/vc_column][vc_column width=”1\/6″][\/vc_column][\/vc_row][vc_row el_class=”dg-index-fix dg-padding-small-top”][vc_column width=”5\/6″ el_class=”dg-padding-none full_width_responsive”][vc_column_text css=””]<\/p>\n

Consultancy<\/h2>\n

VSL provides a periodic time service bulletin. This weekly report with information about the time and phase difference with the national time standard UTC of signals has been measured, allows you to manage your atomic clock to keep track of your internal time standard. <\/p>\n

For resilience of your time system, VSL has developed a resilience consultation. In collaboration with a team of your network specialists, we test the current approach and advise on areas for improvement.[\/vc_column_text][\/vc_column][vc_column width=”1\/6″][\/vc_column][\/vc_row][vc_row el_class=”dg-index-fix dg-padding-small-top”][vc_column width=”5\/6″ el_class=”dg-padding-none full_width_responsive”][vc_column_text css=””]<\/p>\n

Proficiency testing<\/h2>\n

For resilience of your time system, VSL has developed a resilience consultation. In collaboration with a team of your network specialists, we test the current approach and advise on areas for improvement. <\/p>\n

Read more about this on our page on Proficiency Tests<\/a>[\/vc_column_text][\/vc_column][vc_column width=”1\/6″][\/vc_column][\/vc_row][\/vc_section][vc_section full_width=”stretch_row” el_class=”dg-padding-mid brand_element_small” css=”.vc_custom_1669124337953{background-color: #fafafa !important;}”][vc_row el_class=”dg-index-fix dg-padding-small-top”][vc_column width=”5\/6″ el_class=”dg-padding-none full_width_responsive”][vc_column_text css=””]<\/p>\n

VSL Time via fiber optics<\/h2>\n

With access to UTC(VSL) via direct fiber connections and through selected partners, VSL supports organizations that depend on traceable, accurate and reliable time and frequency signals. In this way, VSL serves a broad public interest: strengthening digital infrastructures, telecom networks, financial transactions, energy supply, scientific applications and other critical processes in which reliable time is a prerequisite for security, continuity and innovation. By making the national time standard practically accessible, VSL connects its metrological expertise with the growing need of the market and society for robust, independent and internationally traceable time provision.[\/vc_column_text][vc_column_text css=””]<\/p>\n

Traceability to UTC(VSL)<\/h3>\n

VSL can ensure traceability to UTC(VSL) by not only delivering the time signal to the source, but also metrologically controlling the entire chain between UTC(VSL) and the end-user. This means that all relevant connections, delays and time-related components in the network are characterized and calibrated, such as fiber optic connections, grandmaster clocks, boundary clocks, PTP and White Rabbit equipment, NTP\/PTP servers and any measurement or distribution equipment used. For each component, it is determined what contribution it makes to the total time deviation and measurement uncertainty. By recording these contributions in an uncertainty budget and periodically checking them with traceable measurements, a demonstrable and uninterrupted chain to UTC(VSL) is created. In this way, the user can not only receive time that is comparable, synchronized with the world and can serve as a reference, but also demonstrate with substantiated evidence with what accuracy the time is available. Without synchronized time, systems get out of sync and after a certain period of time there is a malfunction or failure of systems because they can no longer communicate.[\/vc_column_text][vc_column_text css=””]<\/p>\n

VSL Connected<\/h3>\n

By connecting to UTC(VSL), a customer gets direct access to an independent, national and internationally traceable time source. This provides greater certainty because the customer has a controlled connection with known performance and a demonstrable measurement uncertainty, which is independent of disturbable GNSS signals. Depending on the chosen technology, such as NTP, PTP or White Rabbit, the time provision can be tailored to the desired accuracy, availability and application. For organizations in telecom, financial markets, energy, data centers, research, and critical infrastructure, for example, this means that timestamps, network processes, and metrics become reliable and auditable. If desired, VSL supports the customer in drawing up the timing (uncertainty) budget, periodic verification and calibration, so that the quality of the time synchronisation not only works technically, but also remains stable, reliable and demonstrably meets internal, contractual or legal requirements. <\/p>\n

Via this connection, which requires a fiber optic connection to VSL’s clocks, the customer can use UTC(VSL) as an (additional) source for its internal time and frequency synchronization, which better guarantees the continuity of business operations.[\/vc_column_text][vc_column_text css=””]<\/p>\n

VSL Certified<\/h3>\n

It is not desirable or feasible for every organization to make a connection with VSL, which is why VSL has distribution partners who have a direct connection with VSL and who are able to provide third parties with time services.<\/p>\n

VSL assesses the quality system of a distribution partner by determining whether the partner operates the connection to UTC(VSL) in a controlled, demonstrable and reproducible manner. VSL looks at procedures for installation, configuration management, monitoring, incident handling, change management, access security and periodic maintenance of the time infrastructure. It is also assessed whether measuring instruments and time-related components are demonstrably calibrated, whether measurement uncertainties are correctly recorded and whether deviations are identified and followed up in a timely manner. The partner must be able to demonstrate that the distribution chain to the end-user remains under control and that relevant data, such as calibration reports, log files and performance indicators, are available for review. Based on annual audits, document review and technical verifications, VSL can determine how the partner offers reliable and traceable time distribution with the agreed quality.[\/vc_column_text][\/vc_column][vc_column width=”1\/6″][\/vc_column][\/vc_row][\/vc_section][vc_section el_class=”dg-padding-mid brand_element_small”][vc_row el_class=”dg-index-fix dg-padding-small-top”][vc_column width=”5\/6″ el_class=”dg-padding-none full_width_responsive”][vc_column_text css=””]<\/p>\n

The official time of the Netherlands<\/h2>\n

Click here for the official public time in the Netherlands.<\/a>[\/vc_column_text][\/vc_column][vc_column width=”1\/6″][\/vc_column][\/vc_row][\/vc_section][vc_section full_width=”stretch_row” el_class=”dg-padding-mid” css=”.vc_custom_1648640322721{background-color: #fafafa !important;}”][vc_row][vc_column width=”1\/6″][\/vc_column][vc_column width=”2\/3″ el_class=”dg-padding-none full_width_responsive”][vc_column_text]<\/p>\n

Our areas of expertise<\/h2>\n

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