{"id":3505,"date":"2015-12-15T14:31:38","date_gmt":"2015-12-15T13:31:38","guid":{"rendered":"http:\/\/blocs.xtec.cat\/cdacansantoi\/?p=3505"},"modified":"2017-07-06T14:18:31","modified_gmt":"2017-07-06T12:18:31","slug":"anenometres","status":"publish","type":"post","link":"https:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/articles-aparells-meteorologia\/anenometres\/","title":{"rendered":"Anem\u00f2metres"},"content":{"rendered":"<p style=\"text-align: justify;\"><span style=\"color: #3366ff;\"><strong><span style=\"color: #800000;\">Per a qu\u00e8 serveixen?<\/span><br \/>\n<\/strong><\/span>Els anem\u00f2metres s\u00f3n un aparells molt utilitzats\u00a0en meteorologia que serveixen per mesurar la velocitat del vent.<\/p>\n<p style=\"text-align: justify;\">La primera invenci\u00f3 d&#8217;un anem\u00f2metre s&#8217;atribueix a l&#8217;itali\u00e0 Leon Battista Alberti cap a l&#8217;any 1450, que era un tipus d&#8217;anem\u00f2metre de pressi\u00f3. M\u00e9s endavant, l&#8217;any 1846, l&#8217;angl\u00e8s Thomas Romney Robinson va dissenyar el primer anem\u00f2metre de cassoletes.<\/p>\n<p style=\"text-align: justify;\">Con\u00e8ixer la velocitat del vent \u00e9s molt important, no nom\u00e9s per a les prediccions meteorol\u00f2giques, sin\u00f3 tamb\u00e9 per a la seguretat en la navegaci\u00f3 a\u00e8ria, mar\u00edtima i els despla\u00e7aments terrestres amb vehicles.<br \/>\n<span style=\"color: #800000;\"><strong><br \/>\nTipus d&#8217;anem\u00f2metres<br \/>\n<\/strong><\/span>Hi ha dos tipus principals d&#8217;anem\u00f2metres:<\/p>\n<ul style=\"text-align: justify;\">\n<li>Els que mesuren la velocitat del vent: basats principalment en mecanismes que giren segons la velocitat del vent i que, convenientment calibrats, ens indiquen la seva velocitat.<\/li>\n<li>Els que mesuren la pressi\u00f3 del vent: detecten la for\u00e7a del vent exercida sobre una superf\u00edcie plana que normalment\u00a0sofreix\u00a0un despla\u00e7ament segons la for\u00e7a que t\u00e9 el vent.<\/li>\n<\/ul>\n<p>Anem\u00f2metres que mesuren la velocitat del vent:<\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #800000;\"><strong>Anem\u00f2metre de cassoletes<\/strong><\/span><a href=\"http:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/wp-content\/uploads\/usu1385\/2015\/12\/anemometre_cassoletes.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft wp-image-3510\" src=\"http:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/wp-content\/uploads\/usu1385\/2015\/12\/anemometre_cassoletes.jpg\" alt=\"anemometre_cassoletes\" width=\"202\" height=\"286\" \/><br \/>\n<\/a>Consta de 3 semiesferes buides (cassoletes) unides a un eix vertical formant entre s\u00ed angles de 120\u00ba. Quan el vent bufa, les fa girar amb m\u00e9s o menys rapidesa en funci\u00f3 de la seva velocitat. Un dispositiu\u00a0mec\u00e0nic o electr\u00f2nic transforma el moviment de rotaci\u00f3 en un sistema d&#8217;indicaci\u00f3 de la velocitat del vent (agulla sobre una escala graduada, pantalla, etc).<br \/>\nAquest tipus d&#8217;anem\u00f2metre presenta l&#8217;avantatge que no cal orientar-lo segons la direcci\u00f3 del vent. T\u00e9 l&#8217;inconvenient que no \u00e9s massa prec\u00eds quan els vents s\u00f3n fluixos.<\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #800000;\"><strong>Anem\u00f2metre de molinet o d&#8217;h\u00e8lix<br \/>\n<\/strong><\/span><a href=\"http:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/wp-content\/uploads\/usu1385\/2015\/12\/anemometre_helix.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignright size-full wp-image-3513\" src=\"http:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/wp-content\/uploads\/usu1385\/2015\/12\/anemometre_helix.jpg\" alt=\"anemometre_helix\" width=\"220\" height=\"146\" \/><\/a>Presenta una h\u00e8lix que gira segons la velocitat del vent unida a un eix horitzontal; tamb\u00e9 t\u00e9, a l&#8217;altre extrem, una cua (o tim\u00f3) que resulta imprescindible per a orientar correctament l&#8217;aparell de cara a la direcci\u00f3 d&#8217;on ve el vent. De la mateixa forma que el de cassoletes, t\u00e9 un mecanisme que transforma el moviment de rotaci\u00f3 de l&#8217;eix en algun sistema d&#8217;indicaci\u00f3 de velocitat.<\/p>\n<p style=\"text-align: justify;\"><strong><span style=\"color: #800000;\">Anem\u00f2metre de fil calent<br \/>\n<\/span><\/strong><a href=\"http:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/wp-content\/uploads\/usu1385\/2015\/12\/anemometre_fil_calent.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-full wp-image-3514\" src=\"http:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/wp-content\/uploads\/usu1385\/2015\/12\/anemometre_fil_calent.jpg\" alt=\"anemometre_fil_calent\" width=\"130\" height=\"85\" \/><\/a>Es basa en els canvis de temperatura que experimenta un fil conductor molt prim de tungst\u00e8 quan \u00e9s exposat al vent. Com m\u00e9s velocitat t\u00e9 el vent m\u00e9s es refreda el fil; les variacions de temperatura comporten canvis\u00a0en la resist\u00e8ncia el\u00e8ctrica del filament que s\u00f3n calibrats i mesurats de forma electr\u00f2nica, donant, finalment, una expressi\u00f3 de velocitat del vent. S\u00f3n aparells molt precisos.<\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #800000;\"><strong>Anem\u00f2metre d&#8217;ultrasons<br \/>\n<a href=\"http:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/wp-content\/uploads\/usu1385\/2015\/12\/anemometre_ultrasons-e1450184573309.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft wp-image-3516 size-full\" src=\"http:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/wp-content\/uploads\/usu1385\/2015\/12\/anemometre_ultrasons-e1450184573309.jpg\" alt=\"anemometre_ultrasons\" width=\"100\" height=\"130\" \/><\/a><\/strong><\/span>Consten d&#8217;uns aparells emissors i receptors d&#8217;ultrasons separats entre si per uns 20 cm. L&#8217;emissor emet una ona ultras\u00f2nica (la freq\u00fc\u00e8ncia de la qual pot ser modificada en funci\u00f3 de\u00a0la velocitat del vent &#8211; efecte Doppler-) que \u00e9s captada pel receptor. Les variacions de freq\u00fc\u00e8ncia s\u00f3n calibrades electr\u00f2nicament i expressades com a velocitats del vent.<br \/>\n\u00c9s un aparell for\u00e7a prec\u00eds que, a m\u00e9s, presenta l&#8217;avantatge de no tenir parts m\u00f2bils.<\/p>\n<p style=\"text-align: justify;\">Anem\u00f2metres que mesuren la pressi\u00f3 del vent:<\/p>\n<p style=\"text-align: justify;\"><strong><span style=\"color: #800000;\">Anem\u00f2metres de placa plana<\/span><\/strong><br \/>\n<a href=\"http:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/wp-content\/uploads\/usu1385\/2015\/12\/anemometre_bola.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-full wp-image-3517\" src=\"http:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/wp-content\/uploads\/usu1385\/2015\/12\/anemometre_bola.jpg\" alt=\"anemometre_bola\" width=\"90\" height=\"150\" \/><\/a>Consisteix en una placa plana rectangular penjada verticalment sobre un eix i que pot oscil\u00b7lar segons la for\u00e7a del vent. Com m\u00e9s amunt arriba la placa, m\u00e9s velocitat t\u00e9 el vent.<br \/>\nUna altra versi\u00f3 d&#8217;aquest tipus d&#8217;anem\u00f2metre substitueix la placa per una bola. S\u00f3n aparells de mesura no massa precisos i que cal orientar segons la direcci\u00f3 del vent.<\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #800000;\"><strong><a href=\"http:\/\/www.lineaverdeceutatrace.com\/lv\/Recursos-educacion-ambiental\/aire\/anemometro.asp\" target=\"_blank\">Taller: construcci\u00f3 d&#8217;un anem\u00f2metre<\/a><br \/>\n<\/strong><\/span><\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #800000;\"><strong>Refer\u00e8ncies i<\/strong><\/span><span style=\"color: #3366ff;\"><strong><span style=\"color: #800000;\"> enlla\u00e7os<\/span><br \/>\n<\/strong><\/span><\/p>\n<ul style=\"text-align: justify;\">\n<li>Activitats del Camp d&#8217;Aprenentatge relacionades:\n<ul>\n<li><a title=\"Quin temps fa? (CMP)\" href=\"http:\/\/blocs.xtec.cat\/cdacansantoi\/quin-temps-fa\/\" target=\"_blank\">Quin temps fa? (cicle mitj\u00e0 de prim\u00e0ria)<\/a><\/li>\n<li><a title=\"Observaci\u00f3 i mesura del temps atmosf\u00e8ric (CSP)\" href=\"http:\/\/blocs.xtec.cat\/cdacansantoi\/observacio-i-mesura-temps-atmosferic-csp\/\" target=\"_blank\">Observaci\u00f3 i mesura del temps atmosf\u00e8ric (cicle superior de prim\u00e0ria)<\/a><\/li>\n<li><a title=\"Observaci\u00f3 i mesura del temps atmosf\u00e8ric. ESO\" href=\"http:\/\/blocs.xtec.cat\/cdacansantoi\/observacio-i-mesura-del-temps-atmosferic-eso\/\" target=\"_blank\">Observaci\u00f3 i mesura del temps atmosf\u00e8ric (ESO)<\/a><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<ul style=\"list-style-type: square;\">\n<li style=\"text-align: justify;\"><a title=\"Meteorologia\" href=\"http:\/\/blocs.xtec.cat\/cdacansantoi\/el_temps\/\" target=\"_blank\">Dades de l&#8217;estaci\u00f3 meteorol\u00f2gica digital de Can Santoi<\/a><\/li>\n<li style=\"text-align: justify;\"><a href=\"http:\/\/blocs.xtec.cat\/cdacansantoi\/programes-de-suport\/\" target=\"_blank\">Meteomaps: <\/a>programari per a confegir mapes del temps<\/li>\n<li style=\"text-align: justify;\"><a href=\"https:\/\/ca.wikipedia.org\/wiki\/Anem%C3%B2metre\" target=\"_blank\">Viquip\u00e8dia<\/a><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Per a qu\u00e8 serveixen? Els anem\u00f2metres s\u00f3n un aparells molt utilitzats\u00a0en meteorologia que serveixen per mesurar la velocitat del vent. La primera invenci\u00f3 d&#8217;un anem\u00f2metre s&#8217;atribueix a l&#8217;itali\u00e0 Leon Battista Alberti cap a l&#8217;any 1450, que era un tipus d&#8217;anem\u00f2metre de pressi\u00f3. M\u00e9s endavant, l&#8217;any 1846, l&#8217;angl\u00e8s Thomas Romney Robinson va dissenyar el primer anem\u00f2metre [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":8809,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_bbp_topic_count":0,"_bbp_reply_count":0,"_bbp_total_topic_count":0,"_bbp_total_reply_count":0,"_bbp_voice_count":0,"_bbp_anonymous_reply_count":0,"_bbp_topic_count_hidden":0,"_bbp_reply_count_hidden":0,"_bbp_forum_subforum_count":0,"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[376],"tags":[343,331,334,344],"class_list":["post-3505","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-articles-aparells-meteorologia","tag-anemometre","tag-aparell","tag-meteorologia-2","tag-velocitat-del-vent"],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/wp-json\/wp\/v2\/posts\/3505","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/wp-json\/wp\/v2\/comments?post=3505"}],"version-history":[{"count":2,"href":"https:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/wp-json\/wp\/v2\/posts\/3505\/revisions"}],"predecessor-version":[{"id":8810,"href":"https:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/wp-json\/wp\/v2\/posts\/3505\/revisions\/8810"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/wp-json\/wp\/v2\/media\/8809"}],"wp:attachment":[{"href":"https:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/wp-json\/wp\/v2\/media?parent=3505"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/wp-json\/wp\/v2\/categories?post=3505"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/serveiseducatius.xtec.cat\/cda-cansantoi\/wp-json\/wp\/v2\/tags?post=3505"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}