{"id":103,"date":"2023-02-10T09:00:00","date_gmt":"2023-02-10T08:00:00","guid":{"rendered":"https:\/\/arnaud.collignan.net\/blog\/?p=103"},"modified":"2023-04-11T09:24:04","modified_gmt":"2023-04-11T07:24:04","slug":"les-unites-du-systeme-international","status":"publish","type":"post","link":"https:\/\/arnaud.collignan.net\/blog\/2023\/02\/10\/les-unites-du-systeme-international\/","title":{"rendered":"Les unit\u00e9s du syst\u00e8me international"},"content":{"rendered":"\n<p>En ing\u00e9nierie, il est courant que l&#8217;on use d&#8217;unit\u00e9s de mesures tr\u00e9s diverses et parfois assez atypiques. Et bien s\u00fbr, cela multiplie les risques d&#8217;erreurs de calculs lors d&#8217;une conversion d&#8217;une unit\u00e9 en une autre. Par exemple, il m&#8217;arrive parfois d&#8217;avoir \u00e0 traiter des donn\u00e9es exprim\u00e9es en unit\u00e9s imp\u00e9riales (livres par pouces).  Ou bien de voir passer une force indiqu\u00e9e en kgf (kilogramme-force). Ou encore de manipuler des g\u00b2\/Hz (qui sont \u00e9gaux \u00e0 ~100(m\/s\u00b2)\u00b2\/Hz), attention \u00e0 la conversion.<\/p>\n\n\n\n<p>Mais saviez-vous que dans le syst\u00e8me international (SI), <strong>il n&#8217;y a en r\u00e9alit\u00e9 que 7 unit\u00e9s de base<\/strong> \u00e9talonn\u00e9es :<\/p>\n\n\n\n<figure class=\"wp-block-table is-style-regular\"><table><thead><tr><th>Grandeur<\/th><th>Unit\u00e9<\/th><\/tr><\/thead><tbody><tr><td>Intensit\u00e9 \u00e9lectrique<\/td><td>amp\u00e8re (A)<\/td><\/tr><tr><td>Intensit\u00e9 lumineuse<\/td><td>candela (cd)<\/td><\/tr><tr><td>Longueur<\/td><td>m\u00e8tre (m)<\/td><\/tr><tr><td>Masse<\/td><td>kilogramme (kg)<\/td><\/tr><tr><td>Quantit\u00e9 de mati\u00e8re<\/td><td>mole (mol)<\/td><\/tr><tr><td>Temp\u00e9rature<\/td><td>kelvin (\u00b0K)<\/td><\/tr><tr><td>Temps<\/td><td>seconde (s)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>Etonnant de se dire qu&#8217;\u00e0 partir de ses seules unit\u00e9s, et par le jeu des multiples (kilos, nanos&#8230;) et des op\u00e9rations (ratios, produits&#8230;), l&#8217;on obtient l&#8217;ensemble des unit\u00e9s utilis\u00e9es en science.<\/p>\n\n\n\n<p>A ce sujet, je vous sugg\u00e8re cette <a href=\"https:\/\/www.youtube.com\/playlist?list=PLGPWPtcc-r810Z-0nmESOrHGeun5Hpwo7\">excellente s\u00e9rie de vid\u00e9os<\/a> r\u00e9alis\u00e9 par Bruce Benamran sur la chaine YouTube e-Penser.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>En ing\u00e9nierie, il est courant que l&#8217;on use d&#8217;unit\u00e9s de mesures tr\u00e9s diverses et parfois assez atypiques. Et bien s\u00fbr, cela multiplie les risques d&#8217;erreurs&#8230;<\/p>\n<div class=\"more-link-wrapper\"><a class=\"more-link\" href=\"https:\/\/arnaud.collignan.net\/blog\/2023\/02\/10\/les-unites-du-systeme-international\/\">Lire la suite&#8230;<span class=\"screen-reader-text\">Les unit\u00e9s du syst\u00e8me international<\/span><\/a><\/div>\n","protected":false},"author":1,"featured_media":107,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[28,21,8],"class_list":["post-103","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-physique","tag-epistemologie","tag-mesure","tag-physique","entry"],"acf":{"auteur_de_limage":"Ono Kosuki","url_de_lauteur_de_limage":"https:\/\/www.pexels.com\/fr-fr\/photo\/homme-mesurer-planche-bois-a-regle-5973900\/","source":"","url_de_la_source":"","bibliographie":"NF EN ISO 80000","url_de_la_bibliographie":"https:\/\/www.boutique.afnor.org\/fr-fr\/norme\/nf-en-iso-800001\/grandeurs-et-unites-partie-1-generalites\/fa178555\/41450"},"_links":{"self":[{"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/posts\/103","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/comments?post=103"}],"version-history":[{"count":8,"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/posts\/103\/revisions"}],"predecessor-version":[{"id":150,"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/posts\/103\/revisions\/150"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/media\/107"}],"wp:attachment":[{"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/media?parent=103"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/categories?post=103"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/arnaud.collignan.net\/blog\/wp-json\/wp\/v2\/tags?post=103"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}