{"id":57956,"date":"2023-04-22T02:01:37","date_gmt":"2023-04-22T07:01:37","guid":{"rendered":"https:\/\/www.bjultrasonic.com\/how-ultrasonic-waves-are-generated\/"},"modified":"2025-01-27T06:14:26","modified_gmt":"2025-01-27T11:14:26","slug":"how-ultrasonic-waves-are-generated","status":"publish","type":"post","link":"https:\/\/www.bjultrasonic.com\/cs\/how-ultrasonic-waves-are-generated\/","title":{"rendered":"Generov\u00e1n\u00ed ultrazvukov\u00fdch vln: Podrobn\u00e9 vysv\u011btlen\u00ed"},"content":{"rendered":"<p>Ultrazvukov\u00e9 vlny, nepost\u0159ehnuteln\u00e9 lidsk\u00fdm uchem, nach\u00e1zej\u00ed \u0161irok\u00e9 uplatn\u011bn\u00ed v mnoha oblastech, od medic\u00edny p\u0159es pr\u016fmysl a\u017e po \u010dist\u011bn\u00ed.  Jejich generace je fascinuj\u00edc\u00ed proces, op\u00edraj\u00edc\u00ed se o fyzik\u00e1ln\u00ed principy kmit\u00e1n\u00ed a rezonance.  Tento \u010dl\u00e1nek se podrobn\u011bji zab\u00fdv\u00e1 r\u016fzn\u00fdmi metodami generov\u00e1n\u00ed ultrazvuku.<\/p>\n<h3>Piezoelektrick\u00fd jev a jeho vyu\u017eit\u00ed<\/h3>\n<p>Z\u00e1kladn\u00ed princip generace ultrazvuku v naprost\u00e9 v\u011bt\u0161in\u011b aplikac\u00ed spo\u010d\u00edv\u00e1 v piezoelektrick\u00e9m jevu.  Tento jev popisuje schopnost n\u011bkter\u00fdch materi\u00e1l\u016f, nap\u0159\u00edklad k\u0159emene, keramiky (nap\u0159. PZT &#8211; zirkonatan-titanatan olovnat\u00fd) a n\u011bkter\u00fdch polymer\u016f, m\u011bnit sv\u00e9 rozm\u011bry v z\u00e1vislosti na aplikovan\u00e9m elektrick\u00e9m poli.  A naopak, mechanick\u00e9 nam\u00e1h\u00e1n\u00ed t\u011bchto materi\u00e1l\u016f generuje elektrick\u00e9 nap\u011bt\u00ed.  V gener\u00e1torech ultrazvuku se vyu\u017e\u00edv\u00e1 prvn\u00ed z t\u011bchto vlastnost\u00ed.  Piezoelektrick\u00fd element, obvykle ve form\u011b tenk\u00e9 desti\u010dky, je um\u00edst\u011bn mezi dv\u011bma elektrodami.  P\u016fsoben\u00edm st\u0159\u00eddav\u00e9ho elektrick\u00e9ho pole o vysok\u00e9 frekvenci (nad 20 kHz) se element periodicky rozp\u00edn\u00e1 a smr\u0161\u0165uje, \u010d\u00edm\u017e generuje ultrazvukov\u00e9 vlny.  Frekvence ultrazvuku je p\u0159\u00edmo \u00fam\u011brn\u00e1 frekvenci aplikovan\u00e9ho elektrick\u00e9ho pole.<\/p>\n<table class=\"table table-striped table-bordered\">\n<thead>\n<tr>\n<th>Materi\u00e1l<\/th>\n<th>Frekven\u010dn\u00ed rozsah (kHz)<\/th>\n<th>V\u00fdhody<\/th>\n<th>Nev\u00fdhody<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>K\u0159emen<\/td>\n<td>100 &#8211; 1000<\/td>\n<td>Vysok\u00e1 stabilita frekvence<\/td>\n<td>N\u00edzk\u00e1 piezoelektrick\u00e1 citlivost<\/td>\n<\/tr>\n<tr>\n<td>PZT keramika<\/td>\n<td>10 &#8211; 10000<\/td>\n<td>Vysok\u00e1 piezoelektrick\u00e1 citlivost<\/td>\n<td>Ni\u017e\u0161\u00ed stabilita frekvence, k\u0159ehkost<\/td>\n<\/tr>\n<tr>\n<td>Polymern\u00ed piezoelektrika<\/td>\n<td>10 &#8211; 100<\/td>\n<td>Flexibilita, n\u00edzk\u00e1 cena<\/td>\n<td>Ni\u017e\u0161\u00ed v\u00fdkon<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>Magnetostrik\u010dn\u00ed gener\u00e1tory<\/h3>\n<p>Alternativn\u00ed metodou generace ultrazvuku je vyu\u017eit\u00ed magnetostrik\u010dn\u00edho jevu.  Tento jev popisuje zm\u011bnu rozm\u011br\u016f feromagnetick\u00fdch materi\u00e1l\u016f v z\u00e1vislosti na aplikovan\u00e9m magnetick\u00e9m poli.  Magnetostrik\u010dn\u00ed gener\u00e1tory vyu\u017e\u00edvaj\u00ed c\u00edvku, kter\u00e1 generuje st\u0159\u00eddav\u00e9 magnetick\u00e9 pole, kter\u00e9 indukuje vibrace v magnetostrik\u010dn\u00edm materi\u00e1lu (nap\u0159. nikl, \u017eelezo). Tyto vibrace pak generuj\u00ed ultrazvukov\u00e9 vlny.  Magnetostrik\u010dn\u00ed gener\u00e1tory se obvykle pou\u017e\u00edvaj\u00ed pro generov\u00e1n\u00ed ultrazvuku o ni\u017e\u0161\u00edch frekvenc\u00edch a vy\u0161\u0161\u00edch v\u00fdkonech.<\/p>\n<h3>Ostatn\u00ed metody generace ultrazvuku<\/h3>\n<p>Krom\u011b piezoelektrick\u00fdch a magnetostrik\u010dn\u00edch metod existuj\u00ed i dal\u0161\u00ed zp\u016fsoby generace ultrazvuku, by\u0165 m\u00e9n\u011b b\u011b\u017en\u00e9. Pat\u0159\u00ed mezi n\u011b nap\u0159\u00edklad generace ultrazvuku pomoc\u00ed elektroakustick\u00e9 konverze v kapalin\u00e1ch (elektrohydrodynamick\u00e9 gener\u00e1tory) nebo generace pomoc\u00ed laserov\u00fdch paprsk\u016f (optoakustick\u00e9 gener\u00e1tory). Tyto metody se v\u0161ak pou\u017e\u00edvaj\u00ed sp\u00ed\u0161e pro specifick\u00e9 aplikace a v\u00fdzkum.<\/p>\n<h3>Aplikace ultrazvuku<\/h3>\n<p>Generovan\u00e9 ultrazvukov\u00e9 vlny nach\u00e1zej\u00ed \u0161irok\u00e9 uplatn\u011bn\u00ed v r\u016fzn\u00fdch oblastech.  V medic\u00edn\u011b se pou\u017e\u00edvaj\u00ed pro diagnostiku (ultrazvukov\u00e9 zobrazov\u00e1n\u00ed) a terapii (ultrazvukov\u00e1 chirurgie).  V pr\u016fmyslu se ultrazvuk vyu\u017e\u00edv\u00e1 pro \u010di\u0161t\u011bn\u00ed, sva\u0159ov\u00e1n\u00ed, m\u011b\u0159en\u00ed tlou\u0161\u0165ky materi\u00e1l\u016f a defektoskopii.<\/p>\n<p>Z\u00e1v\u011brem lze \u0159\u00edci, \u017ee generace ultrazvuku je zalo\u017eena na n\u011bkolika fyzik\u00e1ln\u00edch principech, p\u0159i\u010dem\u017e nejroz\u0161\u00ed\u0159en\u011bj\u0161\u00ed metodou je vyu\u017eit\u00ed piezoelektrick\u00e9ho jevu.  Rozmanitost materi\u00e1l\u016f a metod umo\u017e\u0148uje generovat ultrazvukov\u00e9 vlny o r\u016fzn\u00fdch frekvenc\u00edch a v\u00fdkonech, kter\u00e9 nach\u00e1zej\u00ed \u0161irok\u00e9 uplatn\u011bn\u00ed v mnoha oblastech lidsk\u00e9 \u010dinnosti.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Ultrazvukov\u00e9 vlny, nepost\u0159ehnuteln\u00e9 lidsk\u00fdm uchem, nach\u00e1zej\u00ed \u0161irok\u00e9 uplatn\u011bn\u00ed v mnoha oblastech, od medic\u00edny p\u0159es pr\u016fmysl a\u017e po \u010dist\u011bn\u00ed. Jejich generace je fascinuj\u00edc\u00ed proces, op\u00edraj\u00edc\u00ed se o fyzik\u00e1ln\u00ed principy kmit\u00e1n\u00ed a rezonance. Tento \u010dl\u00e1nek se podrobn\u011bji zab\u00fdv\u00e1 r\u016fzn\u00fdmi metodami generov\u00e1n\u00ed ultrazvuku. Piezoelektrick\u00fd jev a jeho vyu\u017eit\u00ed Z\u00e1kladn\u00ed princip generace ultrazvuku v naprost\u00e9 v\u011bt\u0161in\u011b aplikac\u00ed spo\u010d\u00edv\u00e1 v<\/p>\n","protected":false},"author":1,"featured_media":26473,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6415],"tags":[],"class_list":["post-57956","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\/57956","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=57956"}],"version-history":[{"count":0,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/posts\/57956\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/media\/26473"}],"wp:attachment":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/media?parent=57956"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/categories?post=57956"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/tags?post=57956"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}