{"id":19677,"date":"2025-05-21T17:23:57","date_gmt":"2025-05-21T15:23:57","guid":{"rendered":"https:\/\/www.acrn.fr\/metrology-vocabulary-explained-simply\/"},"modified":"2026-07-22T16:41:37","modified_gmt":"2026-07-22T14:41:37","slug":"metrology-vocabulary-explained-simply","status":"publish","type":"post","link":"https:\/\/www.acrn.fr\/en\/metrology-vocabulary-explained-simply\/","title":{"rendered":"Metrology vocabulary: definition, calibration, traceability, uncertainty"},"content":{"rendered":"\n<p class=\"has-black-color has-text-color has-link-color wp-elements-11123cef7b66cd6f0ce9a592c3a509c1 wp-block-paragraph\">Metrology is the science of measurement: the set of methods, means and practices that guarantee the trueness and reliability of a measurement, in industry as well as in healthcare or research.<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-a3bb4b013939a543866e80a7c7827684 wp-block-paragraph\">In the industrial world, it plays an essential role: it guarantees measurement reliability, product conformity and process performance. Yet its technical vocabulary (calibration, traceability, uncertainty, trueness\u2026) can seem complex at first glance.<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-ba1127e25bf434ce0712d3324587d0ee wp-block-paragraph\">This article goes through, in order, the key definitions of metrology so you can understand and use this technical vocabulary correctly.<\/p>\n\n\n\n<div class=\"wp-block-rank-math-toc-block\" id=\"rank-math-toc\"><h2>Table of Contents<\/h2><nav><ol><li class=\"\"><a href=\"#what-is-metrology\">What is metrology?<\/a><ol><li class=\"\"><a href=\"#general-definition-of-metrology\">General definition of metrology<\/a><\/li><li class=\"\"><a href=\"#why-does-metrology-matter-in-industry\">Why does metrology matter in industry?<\/a><\/li><\/ol><\/li><li class=\"\"><a href=\"#the-main-branches-of-metrology\">The main branches of metrology<\/a><ol><li class=\"\"><a href=\"#scientific-metrology\">Scientific metrology<\/a><\/li><li class=\"\"><a href=\"#industrial-metrology\">Industrial metrology<\/a><\/li><li class=\"\"><a href=\"#legal-metrology\">Legal metrology<\/a><\/li><\/ol><\/li><li class=\"\"><a href=\"#metrology-terms-explained\">Metrology terms explained<\/a><ol><li class=\"\"><a href=\"#measuring-instrument\">Measuring instrument<\/a><\/li><li class=\"\"><a href=\"#measurand\">Measurand<\/a><\/li><li class=\"\"><a href=\"#resolution\">Resolution<\/a><\/li><li class=\"\"><a href=\"#measuring-range-and-accuracy-class\">Measuring range and accuracy class<\/a><\/li><\/ol><\/li><li class=\"\"><a href=\"#precision-trueness-and-repeatability-whats-the-difference\">Precision, trueness and repeatability: what&#8217;s the difference?<\/a><ol><li class=\"\"><a href=\"#precision\">Precision<\/a><\/li><li class=\"\"><a href=\"#trueness\">Trueness<\/a><\/li><li class=\"\"><a href=\"#repeatability\">Repeatability<\/a><\/li><\/ol><\/li><li class=\"\"><a href=\"#measurement-uncertainty\">Measurement uncertainty<\/a><ol><li class=\"\"><a href=\"#definition\">Definition<\/a><\/li><li class=\"\"><a href=\"#types-of-uncertainty\">Types of uncertainty<\/a><\/li><\/ol><\/li><li class=\"\"><a href=\"#calibration-and-verification-two-complementary-concepts\">Calibration and verification: two complementary concepts<\/a><ol><li class=\"\"><a href=\"#calibration\">Calibration<\/a><\/li><li class=\"\"><a href=\"#verification\">Verification<\/a><\/li><\/ol><\/li><li class=\"\"><a href=\"#calibration-certificate-what-does-it-contain\">Calibration certificate: what does it contain?<\/a><\/li><li class=\"\"><a href=\"#metrological-traceability\">Metrological traceability<\/a><ol><li class=\"\"><a href=\"#what-is-traceability\">What is traceability?<\/a><\/li><li class=\"\"><a href=\"#why-does-it-matter\">Why does it matter?<\/a><\/li><\/ol><\/li><li class=\"\"><a href=\"#reference-organizations-in-metrology\">Reference organizations in metrology<\/a><\/li><li class=\"\"><a href=\"#how-often-should-you-calibrate-your-measuring-instruments\">How often should you calibrate your measuring instruments?<\/a><\/li><li class=\"\"><a href=\"#practical-case-metrology-vocabulary-applied-to-acrn-control-equipment\">Practical case: metrology vocabulary applied to ACRN control equipment<\/a><ol><li class=\"\"><a href=\"#faq-question-1\">What is metrology, in one sentence?<\/a><\/li><li class=\"\"><a href=\"#faq-question-2\">What is the difference between calibration and verification?<\/a><\/li><li class=\"\"><a href=\"#faq-question-3\">What is a measurand?<\/a><\/li><li class=\"\"><a href=\"#faq-question-4\">What is metrological traceability?<\/a><\/li><\/ol><\/li><li class=\"\"><a href=\"#conclusion\">Conclusion<\/a><\/li><\/ol><\/nav><\/div>\n\n\n\n<h2 id=\"what-is-metrology\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-f5e97fbcd9df6ead036afbf881e87317\">What is metrology?<\/h2>\n\n\n\n<h3 id=\"general-definition-of-metrology\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-a4ebe3e9592bc83afcf192a8da1d0be6\">General definition of metrology<\/h3>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-2868f2b9a6a2e79adf7aada134564410 wp-block-paragraph\">More precisely, metrology covers three complementary aspects: the definition of measurement units, the selection and control of instruments, and the estimation of the uncertainty attached to each result. This is what makes a measurement comparable, verifiable and defensible, internally as well as during an audit.<\/p>\n\n\n\n<h3 id=\"why-does-metrology-matter-in-industry\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-2e7445d69e460bca332fb43b7009686d\">Why does metrology matter in industry?<\/h3>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-b7c62a0157d2ab67ba01da3ae25a084a wp-block-paragraph\">Metrology ensures:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"has-black-color has-text-color has-link-color wp-elements-b6b399326dcded699aa363f9e9666de4\">Product conformity to standards.<\/li>\n\n\n\n<li class=\"has-black-color has-text-color has-link-color wp-elements-52e81633f528ee6f5ff6adc0384bd30d\">Safety and quality in industrial processes.<\/li>\n\n\n\n<li class=\"has-black-color has-text-color has-link-color wp-elements-2ea568f3243c712d20b31cd2e8121a75\">Comparability of measurements on an international scale.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\ud83d\udc49 <a href=\"https:\/\/www.acrn.fr\/en\/our-product-lines\/\"><em>Discover our metrology solutions for industry<\/em><\/a><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 id=\"the-main-branches-of-metrology\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-6a927b76418f291a7fb755a8f1facee2\">The main branches of metrology<\/h2>\n\n\n\n<h3 id=\"scientific-metrology\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-bcdd536ab44aa725cbcd70dfb992b6c0\">Scientific metrology<\/h3>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-f601f3ff19b6179ccff39d9058bf913b wp-block-paragraph\">It focuses on fundamental units (metre, kilogram, second\u2026) and their definition through universal constants. It is carried by national and international bodies such as the BIPM (International Bureau of Weights and Measures).<\/p>\n\n\n\n<h3 id=\"industrial-metrology\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-33c3409f2b1edb6df64282bef164c953\">Industrial metrology<\/h3>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-3fed316a4625552ba84aa5de5056c17a wp-block-paragraph\">It&#8217;s the one that concerns us most in the production sector. It ensures that the measuring equipment used in a company meets an adequate level of accuracy.<\/p>\n\n\n\n<h3 id=\"legal-metrology\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-afdb591e806eaedb8b3eef5b768d7154\">Legal metrology<\/h3>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-c3438ac33229b097d6724b7feeac1d43 wp-block-paragraph\">It concerns measuring instruments used in commercial transactions or under regulatory requirements (trade scales, speed cameras, water meters\u2026).<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 id=\"metrology-terms-explained\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-a87dd7b28eb13766f61402e9da51bf1a\">Metrology terms explained<\/h2>\n\n\n\n<h3 id=\"measuring-instrument\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-b3d729cf8c29074348b81194fffc32a1\">Measuring instrument<\/h3>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-1eb6573aff742f31db0dd569a45f2aa2 wp-block-paragraph\">A measuring instrument is any device used to measure a physical quantity (length, weight, temperature, torque\u2026).<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-6ad325280848ecf41d9c8f9e3a11e81e wp-block-paragraph\">Example: micrometer, scale, torquemeter (a tool for measuring torque).<\/p>\n\n\n\n<h3 id=\"measurand\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-2b3f9af15aca0e6aca38e1a6a49c8e68\">Measurand<\/h3>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-ddf835ec42ad15d49b0d6fb0b7707cd6 wp-block-paragraph\">The measurand is the physical quantity you want to measure. Example: the temperature of a liquid, the tightening torque of a screw, the length of a part.<\/p>\n\n\n\n<h3 id=\"resolution\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-38ab4ebbedcd5cd22ef560e3ffa0593b\">Resolution<\/h3>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-927b80f3ea4cdcfb877cf44ffc40b480 wp-block-paragraph\">Resolution is the smallest change in a quantity that an instrument can detect. The finer it is, the more precise the measurement.<\/p>\n\n\n\n<h3 id=\"measuring-range-and-accuracy-class\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-f0da6ece89d4d4ef82c78f9c826f346d\">Measuring range and accuracy class<\/h3>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-a7fe1aea9569ee2ff474c3856386500c wp-block-paragraph\">The measuring range is the span of values an instrument can measure without excessive error, between its minimum and maximum value. The accuracy class indicates the maximum error tolerated by the manufacturer over this range (for example \u00b10.5%). The finer the class, the more reliable the instrument, but also the more it requires rigorous, frequent calibration.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 id=\"precision-trueness-and-repeatability-whats-the-difference\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-e3e9375c58da614513cbdf53abdcbbb3\">Precision, trueness and repeatability: what&#8217;s the difference?<\/h2>\n\n\n\n<h3 id=\"precision\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-4678cd6ee11dfa34a5dfb397a422e820\">Precision<\/h3>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-d22df92fa3d9a79b957afe0014d3a270 wp-block-paragraph\">Precision reflects the dispersion of results obtained from repeated measurements. A precise instrument gives results that are very close to one another.<\/p>\n\n\n\n<h3 id=\"trueness\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-22ad52d6eed7a19d71cfb4feea4d597f\">Trueness<\/h3>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-32abe5b2f012bdd2577fb1f35e135d42 wp-block-paragraph\">Trueness measures the gap between the measured value and the actual value. A true instrument gives a value close to reality.<\/p>\n\n\n\n<h3 id=\"repeatability\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-3a86dcfb6f15e032c402902b929552cd\">Repeatability<\/h3>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-324b6170ee789a7e0139e9ac8b77d861 wp-block-paragraph\">Repeatability is an instrument&#8217;s ability to reproduce consistent measurements under unchanged conditions.<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-d60ece1951cbf9df3c17c2a6a2f0bb70 wp-block-paragraph\">\ud83d\udd0d Remember: a device can be precise but not true, or true but not repeatable. The ideal is to combine all three!<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-1175be37999ce0b9509ada8847230e39 wp-block-paragraph\">A simple way to remember the nuance: imagine shots fired at a target. Shots grouped together but far from the centre are precise, but not true. Shots scattered but centred on average are true, but not precise. Shots grouped right in the centre are precise, true\u2026 and therefore repeatable.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 id=\"measurement-uncertainty\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-67d0e2d4f9a8e8b080b4cd2cc9601b95\">Measurement uncertainty<\/h2>\n\n\n\n<h3 id=\"definition\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-7a9c20aca6d0fcc38f45953783767a6d\">Definition<\/h3>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-7ffc9034c89d96e09080620a9e05330b wp-block-paragraph\">Measurement uncertainty expresses the possible margin of error around the measured result. It is essential for correctly interpreting a measurement.<\/p>\n\n\n\n<h3 id=\"types-of-uncertainty\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-912b39dbbb9e53f0aa8d92e2e7afda2c\">Types of uncertainty<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"has-black-color has-text-color has-link-color wp-elements-1b2bc8a8e49ef8952094e552d221ff13\">Type A uncertainty: estimated using statistical methods.<\/li>\n\n\n\n<li class=\"has-black-color has-text-color has-link-color wp-elements-f6911676c7694c130e8ae13738ada318\">Type B uncertainty: estimated from experience, instrument specifications, etc.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-7981b7eadb9f4c251ba6176d7ab5de7b wp-block-paragraph\">In practice, a calibration certificate often expresses an expanded uncertainty U, obtained by multiplying the standard uncertainty by a coverage factor k (generally k = 2), which corresponds to a confidence level of around 95%.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 id=\"calibration-and-verification-two-complementary-concepts\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-379656bb6797377da7aedc98a9424c83\"><strong>Calibration and verification: two complementary concepts<\/strong><\/h2>\n\n\n\n<h3 id=\"calibration\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-65922c819b386e196bc043c166c49d8f\"><strong>Calibration<\/strong><\/h3>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-502c57585659ef22d14d31ab0094b5c9 wp-block-paragraph\"><strong>Calibration<\/strong> consists of comparing a measuring instrument against a known, traceable reference, in order to determine any errors. It does not result in acceptance or rejection. It is essential to any quality assurance plan.<\/p>\n\n\n\n<h3 id=\"verification\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-27ad2a554e6c046d0fcf83f69e55a9b0\"><strong>Verification<\/strong><\/h3>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-15294862f83c3641a764efc26a6486a7 wp-block-paragraph\"><strong>Verification<\/strong> consists of confirming that an instrument meets defined requirements. It results in a decision: the device is either conforming or not.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 id=\"calibration-certificate-what-does-it-contain\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-fd1771b7cd3d94b2de57d4722445400e\"><strong>Calibration certificate: what does it contain?<\/strong><\/h2>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-44d591adcd65b399b8d5a97a59012750 wp-block-paragraph\">A calibration certificate is the document issued at the end of a calibration. It never states whether an instrument is &#8220;good&#8221; or &#8220;bad&#8221;: it provides the measured values, the deviations observed and the associated uncertainty, leaving you to compare them against your own tolerances.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"has-black-color has-text-color has-link-color wp-elements-2bd5d6428ceaf2fb89f446557b34ac49\">The identification of the instrument and its owner.<\/li>\n\n\n\n<li class=\"has-black-color has-text-color has-link-color wp-elements-60d22dd464009b1cfb531793ec0531d0\">The test conditions (temperature, humidity, etc.).<\/li>\n\n\n\n<li class=\"has-black-color has-text-color has-link-color wp-elements-7e9a99239e0d063712f80728c9d4f07e\">The results obtained and the deviations from the reference.<\/li>\n\n\n\n<li class=\"has-black-color has-text-color has-link-color wp-elements-b5848483a4ecd7ff34a7e3f1cce9c2b8\">The measurement uncertainty attached to each point checked.<\/li>\n\n\n\n<li class=\"has-black-color has-text-color has-link-color wp-elements-319681cf4f9607e62d9c7f133d5014c7\">The metrological reference used and its traceability.<\/li>\n<\/ul>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-c1e2b9ca303e35cf117c18e24ac0c2a7 wp-block-paragraph\">A certificate issued by an accredited laboratory carries the COFRAC mention and logo; a COFRAC-traceable certificate attests to the traceability of the reference standards used, without carrying that accreditation. Both are usable within a quality approach, provided the difference is clearly understood.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 id=\"metrological-traceability\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-27d3b83462c4890e61c4cecb6bf4e71b\"><strong>Metrological traceability<\/strong><\/h2>\n\n\n\n<h3 id=\"what-is-traceability\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-49cdbc7b5e3350e3a941694595ffc16a\"><strong>What is traceability?<\/strong><\/h3>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-8ae86de0c328c931aad8483310b3b57c wp-block-paragraph\"><strong>Metrological traceability<\/strong> guarantees that a measurement can be linked to a national or international reference, through an unbroken chain of calibrations, each with its own uncertainty.<\/p>\n\n\n\n<h3 id=\"why-does-it-matter\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-6cde16cc0ed18351e8e62e52c4fe207f\"><strong>Why does it matter?<\/strong><\/h3>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-4661380ddcb92721a21bd1f830082bbf wp-block-paragraph\">It ensures:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"has-black-color has-text-color has-link-color wp-elements-496e9930880aceeacfc7d3f5e60d25f6\">Comparability of results worldwide.<\/li>\n\n\n\n<li>Conformity with ISO standards (such as ISO 9001 or <a href=\"https:\/\/www.iso.org\/standard\/66912.html\" target=\"_blank\" rel=\"noopener\">ISO\/IEC 17025<\/a>).<\/li>\n\n\n\n<li class=\"has-black-color has-text-color has-link-color wp-elements-939308bedf4a0352cf34e1d1bdd947c3\">Credibility of results in audits and certifications.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 id=\"reference-organizations-in-metrology\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-d011758bf3269e4cb708b77cea615764\"><strong>Reference organizations in metrology<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><a href=\"https:\/\/www.bipm.org\/en\/\" target=\"_blank\" rel=\"noopener\">BIPM (International Bureau of Weights and Measures)<\/a><\/strong>: defines the SI units.<\/li>\n\n\n\n<li><strong><a href=\"https:\/\/www.cofrac.fr\/\" target=\"_blank\" rel=\"noopener\">COFRAC (French Accreditation Committee)<\/a><\/strong>: accredits calibration laboratories in France.<\/li>\n\n\n\n<li><strong><a href=\"https:\/\/www.lne.fr\/\" target=\"_blank\" rel=\"noopener\">LNE (French National Metrology and Testing Laboratory)<\/a><\/strong>: national reference for measurement.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\ud83d\udca1 Good to know: ACRN&#8217;s laboratory is not COFRAC-accredited, but it is <strong>COFRAC-traceable through its reference standards<\/strong>, which guarantees the traceability of every calibration performed. To learn more, see our page dedicated to <a href=\"https:\/\/www.acrn.fr\/en\/calibration-metrology\/\"><em>calibration and metrology<\/em><\/a>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 id=\"how-often-should-you-calibrate-your-measuring-instruments\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-bc56acadcfcf8a75b7fcf2f5839b1785\"><strong>How often should you calibrate your measuring instruments?<\/strong><\/h2>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-74d1045cedf81321f855a34732da346c wp-block-paragraph\">There is no single rule for calibration frequency: it depends on how the instrument is used, its stability over time, and the requirements of your quality system (ISO 9001, IATF 16949\u2026). In practice, the NF ISO 10012 standard recommends defining this frequency based on each instrument&#8217;s own drift history.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Heavy use or harsh environment (shocks, vibration, extreme temperatures): more frequent calibration.<\/li>\n\n\n\n<li>Instrument critical to safety or product conformity: tighter frequency, often annual.<\/li>\n\n\n\n<li>Stable, lightly used instrument: interval can be extended once several calibrations show no drift.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Our teams can help you define this frequency and carry out your <a href=\"https:\/\/www.acrn.fr\/en\/calibration-metrology\/\">calibrations<\/a>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 id=\"practical-case-metrology-vocabulary-applied-to-acrn-control-equipment\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-79b8a5199afe11aba76dc38e1f33e6bf\"><strong>Practical case: metrology vocabulary applied to ACRN control equipment<\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Take the example of a <a href=\"https:\/\/www.acrn.fr\/en\/motorized-torque\/\"><strong>motorized torque tester<\/strong><\/a> used to check the tightening torque applied to a bottle in the food industry:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li class=\"has-black-color has-text-color has-link-color wp-elements-053e5ab727d1ef1911cd422458e6b2e5\"><strong>Measurand<\/strong>: tightening torque in N\u00b7m.<\/li>\n\n\n\n<li class=\"has-black-color has-text-color has-link-color wp-elements-622d5275fe7b5b1e5316850877e115bc\"><strong>Measuring instrument<\/strong>: torquemeter.<\/li>\n\n\n\n<li class=\"has-black-color has-text-color has-link-color wp-elements-646cc354557f98d345ca40d8a647d6a5\"><strong>Trueness<\/strong>: gap between the measurement obtained and the target value.<\/li>\n\n\n\n<li class=\"has-black-color has-text-color has-link-color wp-elements-4f4104d7193285914cd4a44b9ddded88\"><strong>Calibration<\/strong>: carried out regularly against a certified reference.<\/li>\n\n\n\n<li class=\"has-black-color has-text-color has-link-color wp-elements-e3f1bec790f3f33527cb1b5a4a69f12d\"><strong>Traceability<\/strong>: ensured by a calibration chain leading back to a national standard.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Learn more about our <a href=\"https:\/\/www.acrn.fr\/en\/torque-measurement\/\"><em>torque measurement solutions<\/em><\/a>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n<div id=\"rank-math-faq\" class=\"rank-math-block\">\n<div class=\"rank-math-list \">\n<div id=\"faq-question-1\" class=\"rank-math-list-item\">\n<h3 class=\"rank-math-question \">What is metrology, in one sentence?<\/h3>\n<div class=\"rank-math-answer \">\n\n<p>Metrology is the science of measurement: it covers the methods and practices that guarantee the trueness and reliability of a measurement, in industry, research or healthcare.<\/p>\n\n<\/div>\n<\/div>\n<div id=\"faq-question-2\" class=\"rank-math-list-item\">\n<h3 class=\"rank-math-question \">What is the difference between calibration and verification?<\/h3>\n<div class=\"rank-math-answer \">\n\n<p>Calibration compares an instrument against a traceable reference to determine its errors, without judging conformity. Verification, on the other hand, results in a decision: the instrument is declared conforming or not against defined requirements.<\/p>\n\n<\/div>\n<\/div>\n<div id=\"faq-question-3\" class=\"rank-math-list-item\">\n<h3 class=\"rank-math-question \">What is a measurand?<\/h3>\n<div class=\"rank-math-answer \">\n\n<p>The measurand is the physical quantity you are trying to measure: a temperature, a tightening torque, a length, a mass, etc.<\/p>\n\n<\/div>\n<\/div>\n<div id=\"faq-question-4\" class=\"rank-math-list-item\">\n<h3 class=\"rank-math-question \">What is metrological traceability?<\/h3>\n<div class=\"rank-math-answer \">\n\n<p>It is the property of a measurement result that links it to a national or international reference through an unbroken chain of calibrations, each with its own uncertainty.<\/p>\n\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n\n\n<h2 id=\"conclusion\" class=\"wp-block-heading has-black-color has-text-color has-link-color wp-elements-94df90f89c8b17151cc52d40a290b1f5\">Conclusion<\/h2>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-406d8332d081cc859378f7bc80cc69e8 wp-block-paragraph\">Understanding the vocabulary of <strong>metrology<\/strong> is essential for any company that cares about quality and precision. Concepts such as measurement uncertainty, calibration and traceability are not mere technical terms: they guarantee the reliability of processes and customer satisfaction.<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-cd1c7f6aa49b13fc8af0821348939c24 wp-block-paragraph\">By making these concepts accessible, you gain autonomy in your quality processes and efficiency in your inspections.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Metrology is the science of measurement: the set of methods, means and practices that guarantee the trueness and reliability of a measurement, in industry as well as in healthcare or research. In the industrial world, it plays an essential role: it guarantees measurement reliability, product conformity and process performance. Yet its technical vocabulary (calibration, traceability, [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":19673,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"categories":[332],"tags":[],"dipi_cpt_category":[],"class_list":["post-19677","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-our-news"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.acrn.fr\/en\/wp-json\/wp\/v2\/posts\/19677","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.acrn.fr\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.acrn.fr\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.acrn.fr\/en\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.acrn.fr\/en\/wp-json\/wp\/v2\/comments?post=19677"}],"version-history":[{"count":3,"href":"https:\/\/www.acrn.fr\/en\/wp-json\/wp\/v2\/posts\/19677\/revisions"}],"predecessor-version":[{"id":25861,"href":"https:\/\/www.acrn.fr\/en\/wp-json\/wp\/v2\/posts\/19677\/revisions\/25861"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.acrn.fr\/en\/wp-json\/wp\/v2\/media\/19673"}],"wp:attachment":[{"href":"https:\/\/www.acrn.fr\/en\/wp-json\/wp\/v2\/media?parent=19677"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.acrn.fr\/en\/wp-json\/wp\/v2\/categories?post=19677"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.acrn.fr\/en\/wp-json\/wp\/v2\/tags?post=19677"},{"taxonomy":"dipi_cpt_category","embeddable":true,"href":"https:\/\/www.acrn.fr\/en\/wp-json\/wp\/v2\/dipi_cpt_category?post=19677"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}