{"id":57361,"date":"2023-04-25T14:29:35","date_gmt":"2023-04-25T19:29:35","guid":{"rendered":"https:\/\/www.bjultrasonic.com\/what-is-ultrasonic-wave\/"},"modified":"2025-01-27T06:17:49","modified_gmt":"2025-01-27T11:17:49","slug":"what-is-ultrasonic-wave","status":"publish","type":"post","link":"https:\/\/www.bjultrasonic.com\/cs\/what-is-ultrasonic-wave\/","title":{"rendered":"Ultrazvukov\u00e9 vlny: Vlastnosti, vyu\u017eit\u00ed a princip"},"content":{"rendered":"<p>Ultrazvukov\u00e9 vlny jsou mechanick\u00e9 vln\u011bn\u00ed s frekvenc\u00ed vy\u0161\u0161\u00ed ne\u017e 20 kHz, tj. nad horn\u00ed hranic\u00ed sly\u0161itelnosti lidsk\u00e9ho ucha.  Na rozd\u00edl od elektromagnetick\u00e9ho z\u00e1\u0159en\u00ed, jako je sv\u011btlo, ultrazvuk k \u0161\u00ed\u0159en\u00ed vy\u017eaduje prost\u0159ed\u00ed, nap\u0159\u00edklad vzduch, vodu nebo pevn\u00e9 l\u00e1tky. Jeho vlastnosti se li\u0161\u00ed v z\u00e1vislosti na prost\u0159ed\u00ed, ve kter\u00e9m se \u0161\u00ed\u0159\u00ed.  D\u00edky sv\u00fdm specifick\u00fdm vlastnostem nach\u00e1z\u00ed ultrazvuk \u0161irok\u00e9 uplatn\u011bn\u00ed v mnoha oborech, od medic\u00edny po pr\u016fmysl.<\/p>\n<p>\u0160\u00ed\u0159en\u00ed ultrazvuku v r\u016fzn\u00fdch prost\u0159ed\u00edch<\/p>\n<p>Rychlost \u0161\u00ed\u0159en\u00ed ultrazvuku se zna\u010dn\u011b li\u0161\u00ed v z\u00e1vislosti na materi\u00e1lu, kter\u00fdm proch\u00e1z\u00ed.  V pevn\u00fdch l\u00e1tk\u00e1ch se \u0161\u00ed\u0159\u00ed nejrychleji, pomaleji v kapalin\u00e1ch a nejpomaleji v plynech.  Hustota a elasticita materi\u00e1lu hraj\u00ed kl\u00ed\u010dovou roli.  N\u00e1sleduj\u00edc\u00ed tabulka ukazuje p\u0159ibli\u017en\u00e9 rychlosti \u0161\u00ed\u0159en\u00ed ultrazvuku v n\u011bkter\u00fdch b\u011b\u017en\u00fdch materi\u00e1lech:<\/p>\n<table class=\"table table-striped table-bordered\">\n<thead>\n<tr>\n<th>Materi\u00e1l<\/th>\n<th>Rychlost \u0161\u00ed\u0159en\u00ed (m\/s)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Ocel<\/td>\n<td>5900<\/td>\n<\/tr>\n<tr>\n<td>Hlin\u00edk<\/td>\n<td>6400<\/td>\n<\/tr>\n<tr>\n<td>Voda<\/td>\n<td>1500<\/td>\n<\/tr>\n<tr>\n<td>Vzduch<\/td>\n<td>340<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Generov\u00e1n\u00ed ultrazvukov\u00fdch vln<\/p>\n<p>Ultrazvukov\u00e9 vlny se generuj\u00ed pomoc\u00ed piezoelektrick\u00fdch krystal\u016f nebo magnetostrik\u010dn\u00edch materi\u00e1l\u016f.  Piezoelektrick\u00fd jev popisuje schopnost n\u011bkter\u00fdch krystal\u016f generovat elektrick\u00e9 nap\u011bt\u00ed p\u0159i mechanick\u00e9 deformaci a naopak.  Magnetostrik\u010dn\u00ed materi\u00e1ly m\u011bn\u00ed sv\u00e9 rozm\u011bry v z\u00e1vislosti na aplikovan\u00e9m magnetick\u00e9m poli.  V obou p\u0159\u00edpadech se periodick\u00e1 zm\u011bna elektrick\u00e9ho pole nebo magnetick\u00e9ho pole p\u0159en\u00e1\u0161\u00ed na mechanick\u00e9 vibrace, kter\u00e9 generuj\u00ed ultrazvukov\u00e9 vlny.  Frekvence generovan\u00fdch vln z\u00e1vis\u00ed na vlastnostech pou\u017eit\u00e9ho materi\u00e1lu a jeho geometrii.<\/p>\n<p>Aplikace ultrazvuku<\/p>\n<p>Ultrazvukov\u00e9 vlny nach\u00e1zej\u00ed \u0161irok\u00e9 uplatn\u011bn\u00ed v mnoha oblastech. V medic\u00edn\u011b se pou\u017e\u00edvaj\u00ed k diagnostice (ultrazvukov\u00e9 zobrazov\u00e1n\u00ed) a terapii (ultrazvukov\u00e1 terapie). V pr\u016fmyslu se ultrazvuk vyu\u017e\u00edv\u00e1 k \u010di\u0161t\u011bn\u00ed, sva\u0159ov\u00e1n\u00ed, m\u011b\u0159en\u00ed tlou\u0161\u0165ky materi\u00e1l\u016f a detekci vad.  Dal\u0161\u00ed aplikace zahrnuj\u00ed sonary, ultrazvukov\u00e9 senzory v automobilech a pr\u016fmyslov\u00e9 automatizaci.<\/p>\n<p>Vliv ultrazvuku na lidsk\u00e9 t\u011blo<\/p>\n<p>I kdy\u017e se ultrazvuk pou\u017e\u00edv\u00e1 v l\u00e9ka\u0159stv\u00ed, je d\u016fle\u017eit\u00e9 si uv\u011bdomit, \u017ee intenzivn\u00ed ultrazvuk m\u016f\u017ee m\u00edt negativn\u00ed vliv na lidsk\u00e9 t\u011blo.  Vysok\u00e9 intenzity mohou zp\u016fsobit po\u0161kozen\u00ed tk\u00e1n\u00ed.  V\u011bt\u0161ina diagnostick\u00fdch aplikac\u00ed v\u0161ak vyu\u017e\u00edv\u00e1 intenzity ultrazvuku, kter\u00e9 jsou pova\u017eov\u00e1ny za bezpe\u010dn\u00e9.<\/p>\n<p>Ultrazvukov\u00e9 vlny p\u0159edstavuj\u00ed fascinuj\u00edc\u00ed oblast fyziky s \u0161irok\u00fdm spektrem aplikac\u00ed. Jejich vlastnosti a chov\u00e1n\u00ed v r\u016fzn\u00fdch prost\u0159ed\u00edch umo\u017e\u0148uj\u00ed jejich efektivn\u00ed vyu\u017eit\u00ed v mnoha oblastech lidsk\u00e9ho \u017eivota, od medic\u00edny po pr\u016fmyslov\u00e9 procesy.  D\u00e1le se o\u010dek\u00e1v\u00e1 v\u00fdvoj nov\u00fdch aplikac\u00ed s vyu\u017eit\u00edm st\u00e1le sofistikovan\u011bj\u0161\u00edch technologi\u00ed generov\u00e1n\u00ed a detekce ultrazvuku.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Ultrazvukov\u00e9 vlny jsou mechanick\u00e9 vln\u011bn\u00ed s frekvenc\u00ed vy\u0161\u0161\u00ed ne\u017e 20 kHz, tj. nad horn\u00ed hranic\u00ed sly\u0161itelnosti lidsk\u00e9ho ucha. Na rozd\u00edl od elektromagnetick\u00e9ho z\u00e1\u0159en\u00ed, jako je sv\u011btlo, ultrazvuk k \u0161\u00ed\u0159en\u00ed vy\u017eaduje prost\u0159ed\u00ed, nap\u0159\u00edklad vzduch, vodu nebo pevn\u00e9 l\u00e1tky. Jeho vlastnosti se li\u0161\u00ed v z\u00e1vislosti na prost\u0159ed\u00ed, ve kter\u00e9m se \u0161\u00ed\u0159\u00ed. D\u00edky sv\u00fdm specifick\u00fdm vlastnostem nach\u00e1z\u00ed ultrazvuk<\/p>\n","protected":false},"author":1,"featured_media":26469,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6415],"tags":[],"class_list":["post-57361","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog","prodpage-classic"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/posts\/57361","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/comments?post=57361"}],"version-history":[{"count":0,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/posts\/57361\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/media\/26469"}],"wp:attachment":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/media?parent=57361"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/categories?post=57361"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/tags?post=57361"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}