{"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":"2025-09-10T16:13:50","modified_gmt":"2025-09-10T14:13:50","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":"<div class=\"wpb-content-wrapper\"><p>[vc_section full_width=&#8221;stretch_row&#8221; content_placement=&#8221;middle&#8221; css=&#8221;.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;}&#8221; el_class=&#8221;main_header gradient_header dg-position-realtive&#8221;][vc_row equal_height=&#8221;yes&#8221; content_placement=&#8221;middle&#8221; el_class=&#8221;dg-header&#8211;small&#8221;][vc_column width=&#8221;2\/3&#8243; el_class=&#8221;dg-padding-none&#8221;][vc_column_text css=&#8221;.vc_custom_1751637618180{margin-bottom: 0px !important;padding-bottom: 0px !important;}&#8221; el_class=&#8221;text-white&#8221;]<\/p>\n<h1>Metrology for Time and Frequency<\/h1>\n<p>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<p>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=&#8221;1\/3&#8243;][\/vc_column][\/vc_row][\/vc_section][vc_section full_width=&#8221;stretch_row&#8221; disable_element=&#8221;yes&#8221; el_class=&#8221;brand_element_small dg-padding-small&#8221; css=&#8221;.vc_custom_1668430282165{background-color: #fafafa !important;}&#8221;][vc_row][vc_column el_class=&#8221;dg-padding-none&#8221;][vc_btn title=&#8221;Introduction&#8221; style=&#8221;flat&#8221; shape=&#8221;square&#8221; size=&#8221;sm&#8221; css=&#8221;.vc_custom_1666611255704{margin-bottom: 0px !important;border-radius: 5px !important;}&#8221; el_class=&#8221;page_btn page_btn_active&#8221; link=&#8221;url:http%3A%2F%2Fwww.vsl.nl%2Fvakgebieden%2Ftijd-frequentie%2F|title:Introduction%20time%20and%20frequency|&#8221;][vc_btn title=&#8221;Custom services&#8221; style=&#8221;flat&#8221; shape=&#8221;square&#8221; size=&#8221;sm&#8221; css=&#8221;.vc_custom_1666338347652{margin-bottom: 0px !important;margin-left: 25px !important;border-radius: 5px !important;}&#8221; el_class=&#8221;page_btn&#8221; link=&#8221;url:http%3A%2F%2Fwww.vsl.nl%2Fvakgebieden%2Ftijd-frequentie%2Fmaatwerk|title:Custom%20services|&#8221;][vc_btn title=&#8221;Calibration&#8221; style=&#8221;flat&#8221; shape=&#8221;square&#8221; size=&#8221;sm&#8221; css=&#8221;.vc_custom_1666338430804{margin-bottom: 0px !important;margin-left: 25px !important;border-radius: 5px !important;}&#8221; el_class=&#8221;page_btn&#8221; link=&#8221;url:https%3A%2F%2Fwww.vsl.nl%2Fvakgebieden%2Ftijd-frequentie%2Fkalibratie|title:Calibration%20time%20and%20frequency|&#8221;][vc_btn title=&#8221;Proficiency Testing&#8221; style=&#8221;flat&#8221; shape=&#8221;square&#8221; size=&#8221;sm&#8221; css=&#8221;.vc_custom_1666338453060{margin-bottom: 0px !important;margin-left: 25px !important;border-radius: 5px !important;}&#8221; el_class=&#8221;page_btn&#8221; link=&#8221;url:https%3A%2F%2Fwww.vsl.nl%2Fvakgebieden%2Ftijd-frequentie%2Fringvergelijkingen|title:Interlaboratory%20comparisons%20time%20and%20frequency|&#8221;][vc_btn title=&#8221;Training&#8221; style=&#8221;flat&#8221; shape=&#8221;square&#8221; size=&#8221;sm&#8221; css=&#8221;.vc_custom_1666611250033{margin-bottom: 0px !important;margin-left: 25px !important;border-radius: 5px !important;}&#8221; el_class=&#8221;page_btn&#8221; link=&#8221;url:https%3A%2F%2Fwww.vsl.nl%2Fvakgebieden%2Ftijd-frequentie%2Ftraining|title:Training%20time%20and%20frequency|&#8221;][vc_btn title=&#8221;VSL Certification&#8221; style=&#8221;flat&#8221; shape=&#8221;square&#8221; size=&#8221;sm&#8221; css=&#8221;.vc_custom_1666364014026{margin-bottom: 0px !important;margin-left: 25px !important;border-radius: 5px !important;}&#8221; el_class=&#8221;page_btn&#8221; link=&#8221;url:https%3A%2F%2Fwww.vsl.nl%2Fvakgebieden%2Ftijd-frequentie%2Fvsl-certificeringen%2F|title:Training%20time%20and%20frequency|&#8221;][\/vc_column][\/vc_row][\/vc_section][vc_section el_class=&#8221;dg-padding-mid brand_element_small&#8221;][vc_row][vc_column width=&#8221;2\/3&#8243; el_class=&#8221;full_width_responsive dg-padding-none&#8221;][vc_column_text css=&#8221;.vc_custom_1751637704915{padding-right: 10% !important;}&#8221;]<\/p>\n<h2>Calibrations<\/h2>\n<p>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<p>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<p>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=&#8221;1\/3&#8243; css=&#8221;.vc_custom_1757513623900{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;}&#8221; el_class=&#8221;full_width_responsive tablet_expert&#8221;]<div class=\"templatera_shortcode\"><section class=\"vc_section\"><div class=\"vc_row wpb_row vc_row-fluid full_width_responsive\"><div class=\"dg-specialist--inner dg-padding--none-inner wpb_column vc_column_container vc_col-sm-12\"><div class=\"vc_column-inner vc_custom_1757057705883\"><div class=\"wpb_wrapper\">\n\t<div  class=\"wpb_single_image wpb_content_element vc_align_left  vc_custom_1757064441256  dg-expert--image\">\n\t\t\n\t\t<figure class=\"wpb_wrapper vc_figure\">\n\t\t\t<div class=\"vc_single_image-wrapper   vc_box_border_grey\"><img decoding=\"async\" width=\"500\" height=\"333\" data-src=\"https:\/\/www.vsl.nl\/wp-content\/uploads\/2023\/09\/Michael-van-Schaik.jpg\" class=\"vc_single_image-img attachment-full lazyload\" alt=\"\" title=\"Michael van Schaik\" data-srcset=\"https:\/\/www.vsl.nl\/wp-content\/uploads\/2023\/09\/Michael-van-Schaik.jpg 500w, https:\/\/www.vsl.nl\/wp-content\/uploads\/2023\/09\/Michael-van-Schaik-300x200.jpg 300w\" data-sizes=\"(max-width: 500px) 100vw, 500px\"  data-dt-location=\"https:\/\/www.vsl.nl\/en\/?attachment_id=8046\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 500px; --smush-placeholder-aspect-ratio: 500\/333;\" \/><\/div>\n\t\t<\/figure>\n\t<\/div>\n<div class=\"vc_row wpb_row vc_inner vc_row-fluid dg-padding--square vc_custom_1757057909078 vc_row-o-equal-height vc_row-o-content-middle vc_row-flex\"><div class=\"dg-padding--none-inner dg-expert--inner-content wpb_column vc_column_container vc_col-sm-12\"><div class=\"vc_column-inner vc_custom_1757058090823\"><div class=\"wpb_wrapper\">\n\t<div class=\"wpb_text_column wpb_content_element  vc_custom_1757510893821 dg-expert--content-header\" >\n\t\t<div class=\"wpb_wrapper\">\n\t\t\t<h3>Would you like to know more about our services?<\/h3>\n<p>Our experts are happy to help.<\/p>\n\n\t\t<\/div>\n\t<\/div>\n\n\t<div class=\"wpb_text_column wpb_content_element  vc_custom_1757064534319 sector_specialist\" >\n\t\t<div class=\"wpb_wrapper\">\n\t\t\t<p><b>Michael van Schaik<\/b><br \/>\nSr. Accountmanager<\/p>\n\n\t\t<\/div>\n\t<\/div>\n\n\t<div class=\"wpb_raw_code wpb_raw_html wpb_content_element vc_custom_1762246526234\" >\n\t\t<div class=\"wpb_wrapper\">\n\t\t\t<i class=\"far fa-envelope green_icon\"><\/i> <a class=\"custom_link_specialist\" href=\"mailto:vsl@vsl.nl\"> 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=&#8221;dg-index-fix dg-padding-small-top&#8221;][vc_column width=&#8221;5\/6&#8243; el_class=&#8221;dg-padding-none full_width_responsive&#8221;][vc_column_text css=&#8221;&#8221;]<\/p>\n<h2>Time Service Bulletin<\/h2>\n<p>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=&#8221;1\/6&#8243;][\/vc_column][\/vc_row][vc_row el_class=&#8221;dg-index-fix dg-padding-small-top&#8221;][vc_column width=&#8221;5\/6&#8243; el_class=&#8221;dg-padding-none full_width_responsive&#8221;][vc_column_text css=&#8221;&#8221;]<\/p>\n<h2>Consultancy<\/h2>\n<p>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<p>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<h2>Proficiency testing<\/h2>\n<p>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<p>Read more about this on our page on <a href=\"https:\/\/www.vsl.nl\/en\/services\/proficiency-testing\/\">Proficiency Tests<\/a>[\/vc_column_text][\/vc_column][vc_column width=&#8221;1\/6&#8243;][\/vc_column][\/vc_row][\/vc_section][vc_section full_width=&#8221;stretch_row&#8221; el_class=&#8221;dg-padding-mid brand_element_small&#8221; css=&#8221;.vc_custom_1669124337953{background-color: #fafafa !important;}&#8221;][vc_row el_class=&#8221;dg-index-fix dg-padding-small-top&#8221;][vc_column width=&#8221;5\/6&#8243; el_class=&#8221;dg-padding-none full_width_responsive&#8221;][vc_column_text css=&#8221;&#8221;]<\/p>\n<h2>Time Synchronisation<\/h2>\n<p>The distribution of time is an important aspect of the management of Dutch time. The VSL has a wide range of options for you to use UTC(VSL) as a source for your ICT system.<\/p>\n<h3>NTP<\/h3>\n<p>The Dutch government enables VSL to provide direct access to Dutch Time via the internet. This allows you to access our NTP server free of charge. We offer additional services to this public service.<\/p>\n<h3>PTP<\/h3>\n<p>The Precision Time Protocol is the time synchronization system used in networks and situations where more accuracy and reliability is required for traceable UTC.<\/p>\n<p>The Precision Time Protocol is the time synchronization system used in networks and situations where more accuracy and reliability is required for traceable UTC.<\/p>\n<h3>White Rabbit<\/h3>\n<p>For research and development, SURF manages a fibre-optic network on which extremely accurate distribution of time is achieved using the White Rabbit protocol. For commercial applications, an infrastructure has been built that enables you to use this precise technology for your application.[\/vc_column_text][\/vc_column][vc_column width=&#8221;1\/6&#8243;][\/vc_column][\/vc_row][\/vc_section][vc_section full_width=&#8221;stretch_row&#8221; el_class=&#8221;dg-padding-mid&#8221; css=&#8221;.vc_custom_1648640322721{background-color: #fafafa !important;}&#8221;][vc_row][vc_column width=&#8221;1\/6&#8243;][\/vc_column][vc_column width=&#8221;2\/3&#8243; el_class=&#8221;dg-padding-none full_width_responsive&#8221;][vc_column_text]<\/p>\n<h2 style=\"text-align: center;\">Our areas of expertise<\/h2>\n<p>[\/vc_column_text][\/vc_column][vc_column width=&#8221;1\/6&#8243;][\/vc_column][\/vc_row][vc_row el_class=&#8221;dg-padding-small-top&#8221;][vc_column el_class=&#8221;dg-padding-none&#8221;]<div class=\"templatera_shortcode\"><style type=\"text\/css\" data-type=\"vc_shortcodes-custom-css\">.vc_custom_1669633605353{margin-bottom: 10px !important;}.vc_custom_1669633627553{margin-bottom: 10px !important;}.vc_custom_1669633635950{margin-bottom: 10px !important;}.vc_custom_1669633653507{margin-bottom: 10px !important;}.vc_custom_1669633664911{margin-bottom: 10px !important;}.vc_custom_1669633673364{margin-bottom: 10px !important;}.vc_custom_1669633682893{margin-bottom: 10px !important;}.vc_custom_1669633691703{margin-bottom: 10px !important;}.vc_custom_1669633708590{margin-bottom: 10px !important;}.vc_custom_1669633727119{margin-bottom: 10px !important;}.vc_custom_1669633735268{margin-bottom: 10px !important;}.vc_custom_1746716719278{margin-bottom: 10px !important;}<\/style><section class=\"vc_section\"><div class=\"vc_row wpb_row vc_row-fluid dg-index-fix vc_row-o-equal-height vc_row-o-content-top vc_row-flex\"><div class=\"markets_icon wpb_column vc_column_container vc_col-sm-2\"><div class=\"vc_column-inner\"><div class=\"wpb_wrapper\"><div class=\"ult-content-box-container \" >\t<a class=\"ult-content-box-anchor\" href=\"https:\/\/www.vsl.nl\/vakgebieden\/elektriciteit\/\" title=\"Elektriciteit\" >\t\t<div class=\"ult-content-box\" style=\"box-shadow: px px px px none;-webkit-transition: all 700ms ease;-moz-transition: all 700ms ease;-ms-transition: all 700ms ease;-o-transition: all 700ms ease;transition: all 700ms ease;\"  data-hover_box_shadow=\"none\"    >\n\t<div  class=\"wpb_single_image wpb_content_element vc_align_center  vc_custom_1669633605353  sector_icon\">\n\t\t\n\t\t<figure class=\"wpb_wrapper vc_figure\">\n\t\t\t<div class=\"vc_single_image-wrapper   vc_box_border_grey\"><img decoding=\"async\" width=\"100\" height=\"100\" data-src=\"https:\/\/www.vsl.nl\/wp-content\/uploads\/2022\/11\/Electricity.png\" class=\"vc_single_image-img attachment-thumbnail lazyload\" alt=\"\" title=\"Electricity\"  data-dt-location=\"https:\/\/www.vsl.nl\/en\/electricity\/\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 100px; --smush-placeholder-aspect-ratio: 100\/100;\" \/><\/div>\n\t\t<\/figure>\n\t<\/div>\n\n\t<div class=\"wpb_text_column wpb_content_element \" >\n\t\t<div class=\"wpb_wrapper\">\n\t\t\t<p style=\"text-align: center;\"><strong>Elektriciteit<\/strong><\/p>\n\n\t\t<\/div>\n\t<\/div>\n\t\t<\/div>\t<\/a><\/div><\/div><\/div><\/div><div class=\"markets_icon wpb_column vc_column_container vc_col-sm-2\"><div class=\"vc_column-inner\"><div class=\"wpb_wrapper\"><div class=\"ult-content-box-container \" >\t<a class=\"ult-content-box-anchor\" href=\"https:\/\/www.vsl.nl\/vakgebieden\/geometrie\/\" title=\"Geometrie\" >\t\t<div class=\"ult-content-box\" style=\"box-shadow: px px px px none;-webkit-transition: all 700ms ease;-moz-transition: all 700ms ease;-ms-transition: all 700ms ease;-o-transition: all 700ms ease;transition: all 700ms ease;\"  data-hover_box_shadow=\"none\"    >\n\t<div  class=\"wpb_single_image wpb_content_element vc_align_center  vc_custom_1669633627553  sector_icon\">\n\t\t\n\t\t<figure class=\"wpb_wrapper vc_figure\">\n\t\t\t<div class=\"vc_single_image-wrapper   vc_box_border_grey\"><img decoding=\"async\" width=\"100\" height=\"100\" data-src=\"https:\/\/www.vsl.nl\/wp-content\/uploads\/2022\/11\/Geometry.png\" class=\"vc_single_image-img attachment-full lazyload\" alt=\"\" title=\"Geometry\"  data-dt-location=\"https:\/\/www.vsl.nl\/en\/geometry\/\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 100px; --smush-placeholder-aspect-ratio: 100\/100;\" \/><\/div>\n\t\t<\/figure>\n\t<\/div>\n\n\t<div class=\"wpb_text_column wpb_content_element \" >\n\t\t<div class=\"wpb_wrapper\">\n\t\t\t<p style=\"text-align: center;\"><b>Geometrie<\/b><\/p>\n\n\t\t<\/div>\n\t<\/div>\n\t\t<\/div>\t<\/a><\/div><\/div><\/div><\/div><div class=\"markets_icon wpb_column vc_column_container vc_col-sm-2\"><div class=\"vc_column-inner\"><div class=\"wpb_wrapper\"><div class=\"ult-content-box-container \" >\t<a class=\"ult-content-box-anchor\" href=\"https:\/\/www.vsl.nl\/vakgebieden\/druk\/\" title=\"Druk\" >\t\t<div class=\"ult-content-box\" style=\"box-shadow: px px px px none;-webkit-transition: all 700ms ease;-moz-transition: all 700ms ease;-ms-transition: all 700ms ease;-o-transition: all 700ms ease;transition: all 700ms ease;\"  data-hover_box_shadow=\"none\"    >\n\t<div  class=\"wpb_single_image wpb_content_element vc_align_center  vc_custom_1669633635950  sector_icon\">\n\t\t\n\t\t<figure class=\"wpb_wrapper vc_figure\">\n\t\t\t<div class=\"vc_single_image-wrapper   vc_box_border_grey\"><img decoding=\"async\" width=\"100\" height=\"100\" data-src=\"https:\/\/www.vsl.nl\/wp-content\/uploads\/2022\/11\/Pressure.png\" class=\"vc_single_image-img attachment-full lazyload\" alt=\"\" title=\"Pressure\"  data-dt-location=\"https:\/\/www.vsl.nl\/en\/pressure\/\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 100px; --smush-placeholder-aspect-ratio: 100\/100;\" \/><\/div>\n\t\t<\/figure>\n\t<\/div>\n\n\t<div class=\"wpb_text_column wpb_content_element \" >\n\t\t<div class=\"wpb_wrapper\">\n\t\t\t<p style=\"text-align: center;\"><strong>Druk<\/strong><\/p>\n\n\t\t<\/div>\n\t<\/div>\n\t\t<\/div>\t<\/a><\/div><\/div><\/div><\/div><div class=\"markets_icon wpb_column vc_column_container vc_col-sm-2\"><div class=\"vc_column-inner\"><div class=\"wpb_wrapper\"><div class=\"ult-content-box-container \" >\t<a class=\"ult-content-box-anchor\" href=\"https:\/\/www.vsl.nl\/vakgebieden\/temperatuur\/\" title=\"Temperatuur\" >\t\t<div class=\"ult-content-box\" style=\"box-shadow: px px px px none;-webkit-transition: all 700ms ease;-moz-transition: all 700ms ease;-ms-transition: all 700ms ease;-o-transition: all 700ms ease;transition: all 700ms ease;\"  data-hover_box_shadow=\"none\"    >\n\t<div  class=\"wpb_single_image wpb_content_element vc_align_center  vc_custom_1669633653507  sector_icon\">\n\t\t\n\t\t<figure class=\"wpb_wrapper vc_figure\">\n\t\t\t<div class=\"vc_single_image-wrapper   vc_box_border_grey\"><img decoding=\"async\" width=\"100\" height=\"100\" data-src=\"https:\/\/www.vsl.nl\/wp-content\/uploads\/2022\/11\/Temperature.png\" class=\"vc_single_image-img attachment-full lazyload\" alt=\"\" title=\"Temperature\"  data-dt-location=\"https:\/\/www.vsl.nl\/en\/temperature\/\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 100px; --smush-placeholder-aspect-ratio: 100\/100;\" \/><\/div>\n\t\t<\/figure>\n\t<\/div>\n\n\t<div class=\"wpb_text_column wpb_content_element \" >\n\t\t<div class=\"wpb_wrapper\">\n\t\t\t<p style=\"text-align: center;\"><b>Temperatuur<\/b><\/p>\n\n\t\t<\/div>\n\t<\/div>\n\t\t<\/div>\t<\/a><\/div><\/div><\/div><\/div><div class=\"markets_icon wpb_column vc_column_container vc_col-sm-2\"><div class=\"vc_column-inner\"><div class=\"wpb_wrapper\"><div class=\"ult-content-box-container \" >\t<a class=\"ult-content-box-anchor\" href=\"https:\/\/www.vsl.nl\/vakgebieden\/optica\/\" title=\"Licht\" >\t\t<div class=\"ult-content-box\" style=\"box-shadow: px px px px none;-webkit-transition: all 700ms ease;-moz-transition: all 700ms ease;-ms-transition: all 700ms ease;-o-transition: all 700ms ease;transition: all 700ms ease;\"  data-hover_box_shadow=\"none\"    >\n\t<div  class=\"wpb_single_image wpb_content_element vc_align_center  vc_custom_1669633664911  sector_icon\">\n\t\t\n\t\t<figure class=\"wpb_wrapper vc_figure\">\n\t\t\t<div class=\"vc_single_image-wrapper   vc_box_border_grey\"><img decoding=\"async\" width=\"100\" height=\"100\" data-src=\"https:\/\/www.vsl.nl\/wp-content\/uploads\/2022\/11\/Optica.png\" class=\"vc_single_image-img attachment-full lazyload\" alt=\"\" title=\"Optica\"  data-dt-location=\"https:\/\/www.vsl.nl\/en\/optica\/\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 100px; --smush-placeholder-aspect-ratio: 100\/100;\" \/><\/div>\n\t\t<\/figure>\n\t<\/div>\n\n\t<div class=\"wpb_text_column wpb_content_element \" >\n\t\t<div class=\"wpb_wrapper\">\n\t\t\t<p style=\"text-align: center;\"><strong>Optica<\/strong><\/p>\n\n\t\t<\/div>\n\t<\/div>\n\t\t<\/div>\t<\/a><\/div><\/div><\/div><\/div><div class=\"markets_icon wpb_column vc_column_container vc_col-sm-2\"><div class=\"vc_column-inner\"><div class=\"wpb_wrapper\"><div class=\"ult-content-box-container \" >\t<a class=\"ult-content-box-anchor\" href=\"https:\/\/www.vsl.nl\/vakgebieden\/chemie\/\" title=\"Chemie\" >\t\t<div class=\"ult-content-box\" style=\"box-shadow: px px px px none;-webkit-transition: all 700ms ease;-moz-transition: all 700ms ease;-ms-transition: all 700ms ease;-o-transition: all 700ms ease;transition: all 700ms ease;\"  data-hover_box_shadow=\"none\"    >\n\t<div  class=\"wpb_single_image wpb_content_element vc_align_center  vc_custom_1669633673364  sector_icon\">\n\t\t\n\t\t<figure class=\"wpb_wrapper vc_figure\">\n\t\t\t<div class=\"vc_single_image-wrapper   vc_box_border_grey\"><img decoding=\"async\" width=\"100\" height=\"100\" data-src=\"https:\/\/www.vsl.nl\/wp-content\/uploads\/2022\/11\/Chemistry.png\" class=\"vc_single_image-img attachment-full lazyload\" alt=\"\" title=\"Chemistry\"  data-dt-location=\"https:\/\/www.vsl.nl\/en\/chemistry\/\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 100px; --smush-placeholder-aspect-ratio: 100\/100;\" \/><\/div>\n\t\t<\/figure>\n\t<\/div>\n\n\t<div class=\"wpb_text_column wpb_content_element \" >\n\t\t<div class=\"wpb_wrapper\">\n\t\t\t<p style=\"text-align: center;\"><b>Chemie<\/b><\/p>\n\n\t\t<\/div>\n\t<\/div>\n\t\t<\/div>\t<\/a><\/div><\/div><\/div><\/div><\/div><div class=\"vc_row wpb_row vc_row-fluid dg-padding-small-top dg-index-fix vc_row-o-equal-height vc_row-o-content-top vc_row-flex\"><div class=\"markets_icon wpb_column vc_column_container vc_col-sm-2\"><div class=\"vc_column-inner\"><div class=\"wpb_wrapper\"><div class=\"ult-content-box-container \" >\t<a class=\"ult-content-box-anchor\" href=\"https:\/\/www.vsl.nl\/vakgebieden\/ioniserende-straling\/\" title=\"Ioniserende straling\" >\t\t<div class=\"ult-content-box\" style=\"box-shadow: px px px px none;-webkit-transition: all 700ms ease;-moz-transition: all 700ms ease;-ms-transition: all 700ms ease;-o-transition: all 700ms ease;transition: all 700ms ease;\"  data-hover_box_shadow=\"none\"    >\n\t<div  class=\"wpb_single_image wpb_content_element vc_align_center  vc_custom_1669633682893  sector_icon\">\n\t\t\n\t\t<figure class=\"wpb_wrapper vc_figure\">\n\t\t\t<div class=\"vc_single_image-wrapper   vc_box_border_grey\"><img decoding=\"async\" width=\"100\" height=\"100\" data-src=\"https:\/\/www.vsl.nl\/wp-content\/uploads\/2022\/11\/Radiation.png\" class=\"vc_single_image-img attachment-full lazyload\" alt=\"\" title=\"Radiation\"  data-dt-location=\"https:\/\/www.vsl.nl\/en\/radiation\/\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 100px; --smush-placeholder-aspect-ratio: 100\/100;\" \/><\/div>\n\t\t<\/figure>\n\t<\/div>\n\n\t<div class=\"wpb_text_column wpb_content_element \" >\n\t\t<div class=\"wpb_wrapper\">\n\t\t\t<p style=\"text-align: center;\"><strong>Ioniserende<\/strong><br \/>\n<strong>straling<\/strong><\/p>\n\n\t\t<\/div>\n\t<\/div>\n\t\t<\/div>\t<\/a><\/div><\/div><\/div><\/div><div class=\"markets_icon wpb_column vc_column_container vc_col-sm-2\"><div class=\"vc_column-inner\"><div class=\"wpb_wrapper\"><div class=\"ult-content-box-container \" >\t<a class=\"ult-content-box-anchor\" href=\"https:\/\/www.vsl.nl\/vakgebieden\/massa\/\" title=\"Massa\" >\t\t<div class=\"ult-content-box\" style=\"box-shadow: px px px px none;-webkit-transition: all 700ms ease;-moz-transition: all 700ms ease;-ms-transition: all 700ms ease;-o-transition: all 700ms ease;transition: all 700ms ease;\"  data-hover_box_shadow=\"none\"    >\n\t<div  class=\"wpb_single_image wpb_content_element vc_align_center  vc_custom_1669633691703  sector_icon\">\n\t\t\n\t\t<figure class=\"wpb_wrapper vc_figure\">\n\t\t\t<div class=\"vc_single_image-wrapper   vc_box_border_grey\"><img decoding=\"async\" width=\"100\" height=\"100\" data-src=\"https:\/\/www.vsl.nl\/wp-content\/uploads\/2022\/11\/Mass.png\" class=\"vc_single_image-img attachment-full lazyload\" alt=\"\" title=\"Mass\"  data-dt-location=\"https:\/\/www.vsl.nl\/en\/mass\/\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 100px; --smush-placeholder-aspect-ratio: 100\/100;\" \/><\/div>\n\t\t<\/figure>\n\t<\/div>\n\n\t<div class=\"wpb_text_column wpb_content_element \" >\n\t\t<div class=\"wpb_wrapper\">\n\t\t\t<p style=\"text-align: center;\"><b>Massa<\/b><\/p>\n\n\t\t<\/div>\n\t<\/div>\n\t\t<\/div>\t<\/a><\/div><\/div><\/div><\/div><div class=\"markets_icon wpb_column vc_column_container vc_col-sm-2\"><div class=\"vc_column-inner\"><div class=\"wpb_wrapper\"><div class=\"ult-content-box-container \" >\t<a class=\"ult-content-box-anchor\" href=\"https:\/\/www.vsl.nl\/vakgebieden\/stroming\/\" title=\"Stroming\" >\t\t<div class=\"ult-content-box\" style=\"box-shadow: px px px px none;-webkit-transition: all 700ms ease;-moz-transition: all 700ms ease;-ms-transition: all 700ms ease;-o-transition: all 700ms ease;transition: all 700ms ease;\"  data-hover_box_shadow=\"none\"    >\n\t<div  class=\"wpb_single_image wpb_content_element vc_align_center  vc_custom_1669633708590  sector_icon\">\n\t\t\n\t\t<figure class=\"wpb_wrapper vc_figure\">\n\t\t\t<div class=\"vc_single_image-wrapper   vc_box_border_grey\"><img decoding=\"async\" width=\"100\" height=\"100\" data-src=\"https:\/\/www.vsl.nl\/wp-content\/uploads\/2022\/11\/Flow.png\" class=\"vc_single_image-img attachment-full lazyload\" alt=\"\" title=\"Flow\"  data-dt-location=\"https:\/\/www.vsl.nl\/en\/flow\/\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 100px; --smush-placeholder-aspect-ratio: 100\/100;\" \/><\/div>\n\t\t<\/figure>\n\t<\/div>\n\n\t<div class=\"wpb_text_column wpb_content_element \" >\n\t\t<div class=\"wpb_wrapper\">\n\t\t\t<p style=\"text-align: center;\"><strong>Stroming<\/strong><\/p>\n\n\t\t<\/div>\n\t<\/div>\n\t\t<\/div>\t<\/a><\/div><\/div><\/div><\/div><div class=\"markets_icon wpb_column vc_column_container vc_col-sm-2\"><div class=\"vc_column-inner\"><div class=\"wpb_wrapper\"><div class=\"ult-content-box-container \" >\t<a class=\"ult-content-box-anchor\" href=\"https:\/\/www.vsl.nl\/vakgebieden\/tijd-frequentie\/\" title=\"Tijd &amp; Frequentie\" >\t\t<div class=\"ult-content-box\" style=\"box-shadow: px px px px none;-webkit-transition: all 700ms ease;-moz-transition: all 700ms ease;-ms-transition: all 700ms ease;-o-transition: all 700ms ease;transition: all 700ms ease;\"  data-hover_box_shadow=\"none\"    >\n\t<div  class=\"wpb_single_image wpb_content_element vc_align_center  vc_custom_1669633727119  sector_icon\">\n\t\t\n\t\t<figure class=\"wpb_wrapper vc_figure\">\n\t\t\t<div class=\"vc_single_image-wrapper   vc_box_border_grey\"><img decoding=\"async\" width=\"100\" height=\"100\" data-src=\"https:\/\/www.vsl.nl\/wp-content\/uploads\/2022\/11\/Time.png\" class=\"vc_single_image-img attachment-full lazyload\" alt=\"\" title=\"Time\"  data-dt-location=\"https:\/\/www.vsl.nl\/en\/time-2\/\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 100px; --smush-placeholder-aspect-ratio: 100\/100;\" \/><\/div>\n\t\t<\/figure>\n\t<\/div>\n\n\t<div class=\"wpb_text_column wpb_content_element \" >\n\t\t<div class=\"wpb_wrapper\">\n\t\t\t<p style=\"text-align: center;\"><strong>Tijd &amp;<br \/>\nfrequentie<\/strong><\/p>\n\n\t\t<\/div>\n\t<\/div>\n\t\t<\/div>\t<\/a><\/div><\/div><\/div><\/div><div class=\"markets_icon wpb_column vc_column_container vc_col-sm-2\"><div class=\"vc_column-inner\"><div class=\"wpb_wrapper\"><div class=\"ult-content-box-container \" >\t<a class=\"ult-content-box-anchor\" href=\"https:\/\/www.vsl.nl\/vakgebieden\/vocht\/\" title=\"Vocht\" >\t\t<div class=\"ult-content-box\" style=\"box-shadow: px px px px none;-webkit-transition: all 700ms ease;-moz-transition: all 700ms ease;-ms-transition: all 700ms ease;-o-transition: all 700ms ease;transition: all 700ms ease;\"  data-hover_box_shadow=\"none\"    >\n\t<div  class=\"wpb_single_image wpb_content_element vc_align_center  vc_custom_1669633735268  sector_icon\">\n\t\t\n\t\t<figure class=\"wpb_wrapper vc_figure\">\n\t\t\t<div class=\"vc_single_image-wrapper   vc_box_border_grey\"><img decoding=\"async\" width=\"100\" height=\"100\" data-src=\"https:\/\/www.vsl.nl\/wp-content\/uploads\/2022\/11\/Humidity.png\" class=\"vc_single_image-img attachment-full lazyload\" alt=\"\" title=\"Humidity\"  data-dt-location=\"https:\/\/www.vsl.nl\/en\/humidity\/\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 100px; --smush-placeholder-aspect-ratio: 100\/100;\" \/><\/div>\n\t\t<\/figure>\n\t<\/div>\n\n\t<div class=\"wpb_text_column wpb_content_element \" >\n\t\t<div class=\"wpb_wrapper\">\n\t\t\t<p style=\"text-align: center;\"><b>Vocht<\/b><\/p>\n\n\t\t<\/div>\n\t<\/div>\n\t\t<\/div>\t<\/a><\/div><\/div><\/div><\/div><div class=\"markets_icon wpb_column vc_column_container vc_col-sm-2\"><div class=\"vc_column-inner\"><div class=\"wpb_wrapper\"><div class=\"ult-content-box-container \" >\t<a class=\"ult-content-box-anchor\" href=\"https:\/\/www.vsl.nl\/diensten\/datawetenschap\/\" >\t\t<div class=\"ult-content-box\" style=\"box-shadow: px px px px none;-webkit-transition: all 700ms ease;-moz-transition: all 700ms ease;-ms-transition: all 700ms ease;-o-transition: all 700ms ease;transition: all 700ms ease;\"  data-hover_box_shadow=\"none\"    >\n\t<div  class=\"wpb_single_image wpb_content_element vc_align_center  vc_custom_1746716719278  sector_icon\">\n\t\t\n\t\t<figure class=\"wpb_wrapper vc_figure\">\n\t\t\t<div class=\"vc_single_image-wrapper   vc_box_border_grey\"><img decoding=\"async\" width=\"1511\" height=\"1607\" data-src=\"https:\/\/www.vsl.nl\/wp-content\/uploads\/2022\/11\/datascience-diensten-HR.png\" class=\"vc_single_image-img attachment-full lazyload\" alt=\"\" title=\"datascience diensten HR\" data-srcset=\"https:\/\/www.vsl.nl\/wp-content\/uploads\/2022\/11\/datascience-diensten-HR.png 1511w, https:\/\/www.vsl.nl\/wp-content\/uploads\/2022\/11\/datascience-diensten-HR-282x300.png 282w, https:\/\/www.vsl.nl\/wp-content\/uploads\/2022\/11\/datascience-diensten-HR-963x1024.png 963w, https:\/\/www.vsl.nl\/wp-content\/uploads\/2022\/11\/datascience-diensten-HR-768x817.png 768w, https:\/\/www.vsl.nl\/wp-content\/uploads\/2022\/11\/datascience-diensten-HR-1444x1536.png 1444w\" data-sizes=\"(max-width: 1511px) 100vw, 1511px\"  data-dt-location=\"https:\/\/www.vsl.nl\/en\/?attachment_id=23302\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 1511px; --smush-placeholder-aspect-ratio: 1511\/1607;\" \/><\/div>\n\t\t<\/figure>\n\t<\/div>\n\n\t<div class=\"wpb_text_column wpb_content_element \" >\n\t\t<div class=\"wpb_wrapper\">\n\t\t\t<p style=\"text-align: center;\"><b>Datawetenschap<\/b><\/p>\n\n\t\t<\/div>\n\t<\/div>\n\t\t<\/div>\t<\/a><\/div><\/div><\/div><\/div><\/div><\/section><\/div>[\/vc_column][\/vc_row][\/vc_section]<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Metrology for Time and Frequency 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. Innovation also requires improvement in the metrology of time, VSL is therefore involved in&hellip;<\/p>\n","protected":false},"author":2,"featured_media":2233,"parent":2912,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[122],"tags":[],"class_list":["post-2860","page","type-page","status-publish","has-post-thumbnail","hentry","category-security-and-resilience","description-off"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.2 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Time and frequency - VSL<\/title>\n<meta name=\"description\" content=\"High-quality metrology services around time and frequency. 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