{"id":59082,"date":"2023-04-22T00:19:46","date_gmt":"2023-04-22T05:19:46","guid":{"rendered":"https:\/\/www.bjultrasonic.com\/how-to-measure-ultrasonic-sound\/"},"modified":"2025-01-27T06:11:42","modified_gmt":"2025-01-27T11:11:42","slug":"how-to-measure-ultrasonic-sound","status":"publish","type":"post","link":"https:\/\/www.bjultrasonic.com\/cs\/how-to-measure-ultrasonic-sound\/","title":{"rendered":"M\u011b\u0159en\u00ed ultrazvuku: metody a techniky"},"content":{"rendered":"<p>Ultrazvuk je zvuk s frekvenc\u00ed nad 20 kHz, tedy nad hranic\u00ed sly\u0161itelnosti lidsk\u00e9ho ucha. Jeho m\u011b\u0159en\u00ed vy\u017eaduje specializovan\u00e9 techniky a p\u0159\u00edstroje, jeliko\u017e b\u011b\u017en\u00e9 zvukom\u011bry nejsou pro tyto frekvence vhodn\u00e9.  M\u011b\u0159en\u00ed ultrazvuku m\u00e1 \u0161irok\u00e9 uplatn\u011bn\u00ed v r\u016fzn\u00fdch oborech, od l\u00e9ka\u0159sk\u00e9 diagnostiky p\u0159es pr\u016fmyslovou kontrolu a\u017e po ekologick\u00fd monitoring.  Tento \u010dl\u00e1nek se zam\u011b\u0159\u00ed na r\u016fzn\u00e9 metody a techniky m\u011b\u0159en\u00ed ultrazvuku.<\/p>\n<h3>Metody m\u011b\u0159en\u00ed ultrazvuku<\/h3>\n<p>Existuje n\u011bkolik metod pro m\u011b\u0159en\u00ed ultrazvuku, kter\u00e9 se li\u0161\u00ed v principu m\u011b\u0159en\u00ed a pou\u017eit\u00e9m vybaven\u00ed.  Z\u00e1kladn\u00ed metody zahrnuj\u00ed pou\u017eit\u00ed piezoelektrick\u00fdch sn\u00edma\u010d\u016f, mikrofon\u016f s vysokou frekven\u010dn\u00ed odezvou a interferometrick\u00fdch metod.  Piezoelektrick\u00e9 sn\u00edma\u010de jsou nej\u010dast\u011bji pou\u017e\u00edvan\u00e9, proto\u017ee jsou relativn\u011b levn\u00e9, robustn\u00ed a snadno pou\u017eiteln\u00e9.  P\u0159ev\u00e1d\u011bj\u00ed mechanick\u00e9 vibrace ultrazvuku na elektrick\u00fd sign\u00e1l, kter\u00fd je n\u00e1sledn\u011b zpracov\u00e1n a analyzov\u00e1n.  Mikrofony s vysokou frekven\u010dn\u00ed odezvou, i kdy\u017e omezen\u00e9 horn\u00ed frekven\u010dn\u00ed hranic\u00ed,  m\u016f\u017eou b\u00fdt pou\u017eity pro m\u011b\u0159en\u00ed ni\u017e\u0161\u00edch ultrazvukov\u00fdch frekvenc\u00ed. Interferometrick\u00e9 metody poskytuj\u00ed velmi p\u0159esn\u00e9 m\u011b\u0159en\u00ed, ale jsou slo\u017eit\u011bj\u0161\u00ed a dra\u017e\u0161\u00ed.<\/p>\n<h3>Piezoelektrick\u00e9 sn\u00edma\u010de a jejich charakteristiky<\/h3>\n<p>Piezoelektrick\u00e9 sn\u00edma\u010de jsou kl\u00ed\u010dov\u00fdm prvkem p\u0159i m\u011b\u0159en\u00ed ultrazvuku.  D\u016fle\u017eit\u00e9 parametry, kter\u00e9 je pot\u0159eba br\u00e1t v \u00favahu p\u0159i v\u00fdb\u011bru sn\u00edma\u010de, zahrnuj\u00ed:<\/p>\n<table class=\"table table-striped table-bordered\">\n<thead>\n<tr>\n<th>Parametr<\/th>\n<th>Jednotka<\/th>\n<th>Typick\u00e1 hodnota<\/th>\n<th>Pozn\u00e1mka<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Frekven\u010dn\u00ed rozsah<\/td>\n<td>Hz<\/td>\n<td>20 kHz &#8211; 10 MHz<\/td>\n<td>Z\u00e1vis\u00ed na konkr\u00e9tn\u00edm typu sn\u00edma\u010de<\/td>\n<\/tr>\n<tr>\n<td>Citlivost<\/td>\n<td>mV\/Pa<\/td>\n<td>10-100 mV\/Pa<\/td>\n<td>Vy\u0161\u0161\u00ed citlivost = lep\u0161\u00ed detekce slab\u00fdch sign\u00e1l\u016f<\/td>\n<\/tr>\n<tr>\n<td>Sm\u011brov\u00e1 charakteristika<\/td>\n<td>&#8211;<\/td>\n<td>Varia\u010dn\u00ed<\/td>\n<td>Ur\u010duje, jak sn\u00edma\u010d reaguje na zvuk z r\u016fzn\u00fdch sm\u011br\u016f<\/td>\n<\/tr>\n<tr>\n<td>Dynamick\u00fd rozsah<\/td>\n<td>dB<\/td>\n<td>40-80 dB<\/td>\n<td>Rozsah intenzit, kter\u00e9 sn\u00edma\u010d dok\u00e1\u017ee m\u011b\u0159it<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>V\u00fdb\u011br vhodn\u00e9ho piezoelektrick\u00e9ho sn\u00edma\u010de z\u00e1vis\u00ed na konkr\u00e9tn\u00ed aplikaci a po\u017eadovan\u00e9 p\u0159esnosti m\u011b\u0159en\u00ed.<\/p>\n<h3>Zpracov\u00e1n\u00ed sign\u00e1lu a anal\u00fdza dat<\/h3>\n<p>Z\u00edskan\u00fd elektrick\u00fd sign\u00e1l z piezoelektrick\u00e9ho sn\u00edma\u010de je d\u00e1le zpracov\u00e1n pomoc\u00ed speci\u00e1ln\u00edho hardwaru a softwaru.  Tento proces zahrnuje zes\u00edlen\u00ed sign\u00e1lu, filtrov\u00e1n\u00ed \u0161umu a digit\u00e1ln\u00ed konverzi.  Anal\u00fdza dat umo\u017e\u0148uje stanoven\u00ed parametr\u016f ultrazvuku, jako je frekvence, amplituda, intenzita a rychlost \u0161\u00ed\u0159en\u00ed.  Speci\u00e1ln\u00ed softwarov\u00e9 bal\u00ed\u010dky umo\u017e\u0148uj\u00ed zobrazen\u00ed dat v r\u016fzn\u00fdch form\u00e1tech, nap\u0159\u00edklad v \u010dasov\u00e9 nebo frekven\u010dn\u00ed dom\u00e9n\u011b.  Pro pokro\u010dilej\u0161\u00ed anal\u00fdzu se pou\u017e\u00edvaj\u00ed techniky jako Fourierova transformace.<\/p>\n<h3>Kalibrace m\u011b\u0159ic\u00edho syst\u00e9mu<\/h3>\n<p>Pro zaji\u0161t\u011bn\u00ed p\u0159esnosti m\u011b\u0159en\u00ed je nezbytn\u00e1 kalibrace cel\u00e9ho m\u011b\u0159ic\u00edho syst\u00e9mu. Kalibrace se prov\u00e1d\u00ed pomoc\u00ed kalibra\u010dn\u00edch zdroj\u016f ultrazvuku s p\u0159esn\u011b definovan\u00fdmi parametry.  Pravideln\u00e1 kalibrace je d\u016fle\u017eit\u00e1 pro udr\u017een\u00ed p\u0159esnosti m\u011b\u0159en\u00ed a minimalizaci chyb.  V n\u011bkter\u00fdch p\u0159\u00edpadech m\u016f\u017ee b\u00fdt nutn\u00e9 pou\u017e\u00edt standardy pro kalibraci od akreditovan\u00fdch laborato\u0159\u00ed.<\/p>\n<p>Z\u00e1v\u011brem lze \u0159\u00edci, \u017ee m\u011b\u0159en\u00ed ultrazvuku je komplexn\u00ed \u00fakol, kter\u00fd vy\u017eaduje znalost r\u016fzn\u00fdch metod, vybaven\u00ed a technik zpracov\u00e1n\u00ed sign\u00e1lu.  Spr\u00e1vn\u00fd v\u00fdb\u011br sn\u00edma\u010d\u016f a kalibrace m\u011b\u0159ic\u00edho syst\u00e9mu jsou kl\u00ed\u010dov\u00e9 pro dosa\u017een\u00ed p\u0159esn\u00fdch a spolehliv\u00fdch v\u00fdsledk\u016f.  Pou\u017eit\u00ed modern\u00edch technologi\u00ed a softwaru umo\u017e\u0148uje detailn\u00ed anal\u00fdzu ultrazvukov\u00fdch sign\u00e1l\u016f a jejich aplikaci v mnoha oblastech lidsk\u00e9 \u010dinnosti.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Ultrazvuk je zvuk s frekvenc\u00ed nad 20 kHz, tedy nad hranic\u00ed sly\u0161itelnosti lidsk\u00e9ho ucha. Jeho m\u011b\u0159en\u00ed vy\u017eaduje specializovan\u00e9 techniky a p\u0159\u00edstroje, jeliko\u017e b\u011b\u017en\u00e9 zvukom\u011bry nejsou pro tyto frekvence vhodn\u00e9. M\u011b\u0159en\u00ed ultrazvuku m\u00e1 \u0161irok\u00e9 uplatn\u011bn\u00ed v r\u016fzn\u00fdch oborech, od l\u00e9ka\u0159sk\u00e9 diagnostiky p\u0159es pr\u016fmyslovou kontrolu a\u017e po ekologick\u00fd monitoring. Tento \u010dl\u00e1nek se zam\u011b\u0159\u00ed na r\u016fzn\u00e9 metody a<\/p>\n","protected":false},"author":1,"featured_media":42067,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6415],"tags":[],"class_list":["post-59082","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\/59082","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=59082"}],"version-history":[{"count":0,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/posts\/59082\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/media\/42067"}],"wp:attachment":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/media?parent=59082"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/categories?post=59082"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/tags?post=59082"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}