Ultrazvukov\u00e9 vlny, neviditeln\u00e9 a nesly\u0161iteln\u00e9 pro lidsk\u00e9 ucho, se pou\u017e\u00edvaj\u00ed v \u0161irok\u00e9 \u0161k\u00e1le aplikac\u00ed, od l\u00e9ka\u0159sk\u00fdch diagnostick\u00fdch n\u00e1stroj\u016f po pr\u016fmyslov\u00e9 \u010distic\u00ed syst\u00e9my. Nicm\u00e9n\u011b, v n\u011bkter\u00fdch situac\u00edch je pot\u0159eba tyto vlny blokovat, a\u0165 u\u017e pro ochranu citliv\u00e9 elektroniky, sn\u00ed\u017een\u00ed hluku, nebo z d\u016fvodu soukrom\u00ed. Blokov\u00e1n\u00ed ultrazvuku nen\u00ed trivi\u00e1ln\u00ed \u00fakol, ale existuje n\u011bkolik metod, kter\u00e9 se daj\u00ed s r\u016fznou \u00fa\u010dinnost\u00ed pou\u017e\u00edt.<\/p>\n
Absorpce ultrazvuku<\/p>\n
Jednou z nejefektivn\u011bj\u0161\u00edch metod je absorpce ultrazvukov\u00fdch vln materi\u00e1lem, kter\u00fd je pro n\u011b nepr\u016fhledn\u00fd. Materi\u00e1l s vysokou hustotou a vnit\u0159n\u00ed strukturou, kter\u00e1 \u00fa\u010dinn\u011b rozptyluje energii vlny, je nejvhodn\u011bj\u0161\u00ed. Mezi vhodn\u00e9 materi\u00e1ly pat\u0159\u00ed nap\u0159\u00edklad hust\u00e9 p\u011bny, speci\u00e1ln\u00ed polymery a n\u011bkter\u00e9 druhy gumy. \u00da\u010dinnost absorpce z\u00e1vis\u00ed na frekvenci ultrazvuku a tlou\u0161\u0165ce pou\u017eit\u00e9ho materi\u00e1lu. Obecn\u011b plat\u00ed, \u017ee vy\u0161\u0161\u00ed frekvence vy\u017eaduj\u00ed siln\u011bj\u0161\u00ed absorp\u010dn\u00ed vrstvu.<\/p>\n
Materi\u00e1l\n\u00da\u010dinnost absorpce (p\u0159ibli\u017en\u00e1) p\u0159i 40kHz\nPozn\u00e1mka\n\nHust\u00e1 polyuretanov\u00e1 p\u011bna\n60-80%\n\u00da\u010dinnost z\u00e1vis\u00ed na hustot\u011b a struktu\u0159e p\u011bny\n\nButylkau\u010duk\n70-90%\nDobr\u00e1 absorpce, ale m\u016f\u017ee b\u00fdt drah\u00fd\n\nSpeci\u00e1ln\u00ed polymern\u00ed kompozit\n>90%\nVysok\u00e1 cena, ale vynikaj\u00edc\u00ed absorp\u010dn\u00ed vlastnosti<\/code><\/pre>\nOdraz ultrazvuku<\/p>\n
Alternativou k absorpci je odraz ultrazvuku. K tomu se pou\u017e\u00edvaj\u00ed materi\u00e1ly s vysokou akustickou impedanc\u00ed, kter\u00e9 odr\u00e1\u017eej\u00ed v\u011bt\u0161inu dopadaj\u00edc\u00ed energie zp\u011bt do zdroje. Tvrd\u00e9 a hladk\u00e9 povrchy, jako je nap\u0159\u00edklad kov nebo sklo, jsou v tomto ohledu \u00fa\u010dinn\u00e9. \u00dahel dopadu ultrazvukov\u00e9 vlny ovliv\u0148uje m\u00edru odrazu \u2013 kolm\u00fd dopad vede k nejvy\u0161\u0161\u00edmu odrazu. Pro efektivn\u00ed blokov\u00e1n\u00ed je nutn\u00e9 vytvo\u0159it bari\u00e9ru z materi\u00e1lu s vysokou odrazivost\u00ed.<\/p>\n
Difrakce ultrazvuku<\/p>\n
Difrakce, neboli ohyb ultrazvukov\u00fdch vln, m\u016f\u017ee b\u00fdt pou\u017eita k jejich rozpt\u00fdlen\u00ed. Struktury s nepravideln\u00fdm povrchem nebo s otvory rozptyluj\u00ed energii ultrazvuku do r\u016fzn\u00fdch sm\u011br\u016f, \u010d\u00edm\u017e sni\u017euj\u00ed jeho intenzitu v c\u00edlov\u00e9m bod\u011b. Tento p\u0159\u00edstup je m\u00e9n\u011b \u00fa\u010dinn\u00fd ne\u017e absorpce nebo odraz, ale m\u016f\u017ee b\u00fdt u\u017eite\u010dn\u00fd v situac\u00edch, kde je prostorov\u011b omezen\u00e1 instalace.<\/p>\n
Kombin\u00e1cia metod<\/p>\n
Pro dosa\u017een\u00ed maxim\u00e1ln\u00ed \u00fa\u010dinnosti blokov\u00e1n\u00ed ultrazvuku se \u010dasto kombinuj\u00ed r\u016fzn\u00e9 metody. Nap\u0159\u00edklad, vrstva absorp\u010dn\u00edho materi\u00e1lu m\u016f\u017ee b\u00fdt um\u00edst\u011bna za odrazivou bari\u00e9rou, aby se minimalizoval pr\u016fnik zbyl\u00fdch vln. Volba optim\u00e1ln\u00ed kombinace z\u00e1vis\u00ed na specifick\u00fdch po\u017eadavc\u00edch dan\u00e9 aplikace a charakteristik\u00e1ch ultrazvukov\u00e9ho zdroje.<\/p>\n
Z\u00e1v\u011brem lze \u0159\u00edci, \u017ee blokov\u00e1n\u00ed ultrazvukov\u00fdch vln je mo\u017en\u00e9 pomoc\u00ed r\u016fzn\u00fdch metod, v\u010detn\u011b absorpce, odrazu a difrakce. V\u00fdb\u011br nejvhodn\u011bj\u0161\u00ed metody z\u00e1vis\u00ed na frekvenci ultrazvuku, po\u017eadovan\u00e9 \u00farovni blokov\u00e1n\u00ed a dal\u0161\u00edch faktorech. \u010casto je nejefektivn\u011bj\u0161\u00ed kombinovat r\u016fzn\u00e9 techniky pro dosa\u017een\u00ed optim\u00e1ln\u00edch v\u00fdsledk\u016f.<\/p>\n","protected":false},"excerpt":{"rendered":"
Ultrazvukov\u00e9 vlny, neviditeln\u00e9 a nesly\u0161iteln\u00e9 pro lidsk\u00e9 ucho, se pou\u017e\u00edvaj\u00ed v \u0161irok\u00e9 \u0161k\u00e1le aplikac\u00ed, od l\u00e9ka\u0159sk\u00fdch diagnostick\u00fdch n\u00e1stroj\u016f po pr\u016fmyslov\u00e9 \u010distic\u00ed syst\u00e9my. Nicm\u00e9n\u011b, v n\u011bkter\u00fdch situac\u00edch je pot\u0159eba tyto vlny blokovat, a\u0165 u\u017e pro ochranu citliv\u00e9 elektroniky, sn\u00ed\u017een\u00ed hluku, nebo z d\u016fvodu soukrom\u00ed. Blokov\u00e1n\u00ed ultrazvuku nen\u00ed trivi\u00e1ln\u00ed \u00fakol, ale existuje n\u011bkolik metod, kter\u00e9 se daj\u00ed<\/p>\n","protected":false},"author":1,"featured_media":26476,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6415],"tags":[],"class_list":["post-60841","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\/60841","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=60841"}],"version-history":[{"count":0,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/posts\/60841\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/media\/26476"}],"wp:attachment":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/media?parent=60841"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/categories?post=60841"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/tags?post=60841"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}