{"id":5916,"date":"2021-11-20T10:10:44","date_gmt":"2021-11-20T03:10:44","guid":{"rendered":"https:\/\/www.vietlearn.org\/post\/?p=5916"},"modified":"2021-11-20T13:24:12","modified_gmt":"2021-11-20T06:24:12","slug":"vi-sao-chuong-canh-bao-phong-trom-co-the-tu-dong-keu","status":"publish","type":"post","link":"https:\/\/www.vietlearn.org\/kien-thuc\/vi-sao-chuong-canh-bao-phong-trom-co-the-tu-dong-keu\/","title":{"rendered":"V\u00ec sao chu\u00f4ng c\u1ea3nh b\u00e1o ph\u00f2ng tr\u1ed9m c\u00f3 th\u1ec3 t\u1ef1 \u0111\u1ed9ng k\u00eau?"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u1ede nh\u1eefng n\u01a1i quan tr\u1ecdng nh\u01b0 ch\u1ed7 c\u1ea5t gi\u1eef ti\u1ec1n nong, v\u00e0ng b\u1ea1c, nh\u00e0 kho hi\u1ec7u bu\u00f4n, l\u01b0u tr\u1eef h\u1ed3 s\u01a1 c\u01a1 m\u1eadt v.v., n\u1ebfu c\u00f3 k\u1ebb gian \u0111\u1ed9t nhi\u00ean l\u1ebbn v\u00e0o, chu\u00f4ng c\u1ea3nh b\u00e1o ph\u00f2ng tr\u1ed9m li\u1ec1n l\u1eadp t\u1ee9c t\u1ef1 \u0111\u1ed9ng k\u00eau: \u0111\u00e8n \u0111\u1ecf nh\u00e1y s\u00e1ng li\u00ean h\u1ed3i, c\u00f2i b\u00e1o \u0111\u1ed9ng r\u00fa l\u00ean \u0111inh tai nh\u1ee9c \u00f3c \u0111\u1ec3 b\u00e1o cho nh\u00e2n vi\u00ean tr\u1ef1c ban nhanh ch\u00f3ng \u00e1p d\u1ee5ng c\u00e1c bi\u1ec7n ph\u00e1p b\u1ea3o v\u1ec7 an to\u00e0n.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Chu\u00f4ng c\u1ea3nh b\u00e1o ph\u00f2ng tr\u1ed9m c\u00f3 th\u1ec3 t\u1ef1 \u0111\u1ed9ng c\u1ea3nh b\u00e1o l\u00e0 v\u00ec n\u00f3 \u0111\u01b0\u1ee3c l\u1eafp c\u00e1i c\u1ea3m bi\u1ebfn h\u1ed3ng ngo\u1ea1i v\u00e0 m\u1ed9t b\u1ed9 thi\u1ebft b\u1ecb b\u00e1o \u0111\u1ed9ng t\u1ef1 \u0111\u1ed9ng.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Nhi\u1ec7t \u0111\u1ed9 c\u1ee7a c\u00e1c lo\u1ea1i v\u1eadt th\u1ec3, ch\u1ec9 c\u1ea7n cao h\u01a1n \u2013273 \u00b0C, \u0111\u1ec1u c\u00f3 th\u1ec3 ph\u00e1t ra tia h\u1ed3ng ngo\u1ea1i. Ng\u01b0\u1eddi ta c\u00f3 nhi\u1ec7t \u0111\u1ed9 c\u01a1 th\u1ec3, c\u0169ng kh\u00f4ng ph\u1ea3i l\u00e0 ngo\u1ea1i l\u1ec7. V\u00ec v\u1eady, m\u1ed9t khi k\u1ebb gian l\u1ebbn v\u00e0o khu v\u1ef1c c\u1ea3nh gi\u1edbi ph\u00f2ng tr\u1ed9m, tia h\u1ed3ng ngo\u1ea1i t\u1eeb th\u00e2n th\u1ec3 c\u1ee7a h\u1eafn ph\u00e1t ra, th\u00f4ng qua th\u1ea5u k\u00ednh trong c\u00e1i c\u1ea3m bi\u1ebfn h\u1ed3ng ngo\u1ea1i t\u1ee5 ti\u00eau v\u00e0 t\u1ea5m chuy\u1ec3n \u0111\u1ed5i quang \u0111i\u1ec7n, li\u1ec1n h\u00ecnh th\u00e0nh l\u00ean t\u00edn hi\u1ec7u xung \u0111i\u1ec7n h\u1ed3ng ngo\u1ea1i c\u00f3 t\u1ea7n s\u1ed1 l\u00e0 0,5 &#8211; 20 Hz. Qua ph\u00f3ng \u0111\u1ea1i c\u1ee7a c\u00e1i khu\u1ebfch \u0111\u1ea1i, sau khi c\u01b0\u1eddng \u0111\u1ed9 \u0111\u01b0\u1ee3c t\u0103ng m\u1ea1nh, t\u00edn hi\u1ec7u s\u1ebd k\u00edch ph\u00e1t s\u1ef1 ho\u1ea1t \u0111\u1ed9ng c\u1ee7a b\u1ed9 dao \u0111\u1ed9ng \u00e2m t\u1ea7n, truy\u1ec1n ra m\u1ed9t t\u00edn hi\u1ec7u \u0111i\u1ec7n \u00e2m t\u1ea7n c\u00f3 t\u1ea7n s\u1ed1 10 kHz. Sau khi \u0111\u00f3 n\u00f3 \u0111\u01b0\u1ee3c \u0111i\u1ec1u ch\u1ebf trong m\u00e1y ph\u00e1t si\u00eau cao t\u1ea7n 49,7 MHz, th\u00f4ng qua s\u00f3ng v\u00f4 tuy\u1ebfn \u0111i\u1ec7n ph\u00e1t \u0111i. Khi \u1ea5y, chi\u1ebfc m\u00e1y thu si\u00eau cao t\u1ea7n \u0111\u1eb7t \u1edf xa t\u1eadn ch\u1ed7 nh\u00e2n vi\u00ean tr\u1ef1c ban li\u1ec1n thu l\u1ea5y s\u00f3ng v\u00f4 tuy\u1ebfn \u0111i\u1ec7n \u0111\u00f3, th\u00f4ng qua x\u1eed l\u00ed lo\u1ea1i b\u1ecf ph\u1ea7n si\u00eau cao t\u1ea7n, ho\u00e0n nguy\u00ean ra t\u00edn hi\u1ec7u \u00e2m t\u1ea7n 10 kHz, ph\u00e1t qua loa cao \u00e2m, \u00e2m \u0111i\u1ec7u h\u1ebft s\u1ee9c ch\u00f3i g\u1eaft. C\u00f9ng l\u00fac, ngu\u1ed3n \u0111i\u1ec7n c\u1ee7a \u0111\u00e8n \u0111\u1ecf c\u1ea3nh b\u00e1o c\u0169ng \u0111\u01b0\u1ee3c n\u1ed1i th\u00f4ng, l\u1eadp t\u1ee9c nh\u00e1y s\u00e1ng. \u00c2m thanh v\u00e0 \u00e1nh s\u00e1ng hi\u1ec7p \u0111\u1ed3ng, t\u1ef1 \u0111\u1ed9ng c\u1ea3nh b\u00e1o m\u1ed9t c\u00e1ch h\u1eefu hi\u1ec7u, c\u00f3 t\u00e1c d\u1ee5ng ph\u00f2ng tr\u1ed9m.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Song lo\u1ea1i c\u1ea3m bi\u1ebfn n\u00e0y y\u00eau c\u1ea7u \u0111\u01b0\u1ee3c l\u1eafp \u1edf \u0111\u1ed9 cao c\u00e1ch m\u1eb7t \u0111\u1ea5t kho\u1ea3ng 2 m, v\u00e0 c\u00f2n ph\u1ea3i c\u00f3 g\u00f3c nh\u00ecn xu\u1ed1ng kho\u1ea3ng 15\u00b0 \u0111\u1ed1i v\u1edbi \u0111\u1ea5t th\u00ec m\u1edbi thu \u0111\u01b0\u1ee3c tia h\u1ed3ng ngo\u1ea1i t\u1eeb c\u01a1 th\u1ec3 ng\u01b0\u1eddi ph\u00e1t ra m\u1ed9t c\u00e1ch nh\u1ea1y c\u1ea3m. Ngo\u00e0i ra c\u00f2n ph\u1ea3i tr\u00e1nh xa ngu\u1ed3n nhi\u1ec7t v\u00e0 \u00e1nh M\u1eb7t Tr\u1eddi chi\u1ebfu th\u1eb3ng v\u00e0o.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00f2n c\u00f3 m\u1ed9t lo\u1ea1i c\u1ea3nh b\u00e1o ph\u00f2ng tr\u1ed9m, c\u00f3 th\u1ec3 ch\u1ee7 \u0111\u1ed9ng ph\u00e1t x\u1ea1 tia h\u1ed3ng ngo\u1ea1i \u0111\u00e3 qua \u0111i\u1ec1u ch\u1ebf, chi\u1ebfu th\u1eb3ng v\u00e0o n\u01a1i c\u1ea7n ph\u00f2ng tr\u1ed9m. M\u1ed9t khi c\u00f3 k\u1ebb gian l\u1ecdt v\u00e0o, h\u1eafn s\u1ebd che l\u1ea5p tia h\u1ed3ng ngo\u1ea1i, l\u00e0m cho c\u00e1i c\u1ea3m bi\u1ebfn h\u1ed3ng ngo\u1ea1i kh\u00f4ng c\u00f3 \u0111\u1ea7u ra chuy\u1ec3n \u0111\u1ed5i c\u1ee7a t\u00edn hi\u1ec7u \u0111i\u1ec7n, l\u1eadp t\u1ee9c kh\u1edfi \u0111\u1ed9ng m\u1ea1ch \u0111i\u1ec7n c\u1ea3nh b\u00e1o, trong loa ph\u00e1t ra ti\u1ebfng b\u00e1o \u0111\u1ed9ng ch\u00f3i g\u1eaft, \u0111\u1ed3ng th\u1eddi \u0111\u00e8n \u0111\u1ecf nh\u00e1y s\u00e1ng, d\u00f9ng \u00e2m thanh v\u00e0 \u00e1nh s\u00e1ng c\u1ea3nh b\u00e1o cho nh\u00e2n vi\u00ean tr\u1ef1c ban.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Trong s\u1ed1 c\u00e1c thi\u1ebft b\u1ecb t\u1ef1 \u0111\u1ed9ng c\u1ea3nh b\u00e1o <a href=\"https:\/\/www.vietlearn.org\" data-internallinksmanager029f6b8e52c=\"2\" title=\"Vietlearn\" rel=\"nofollow\">thi\u1ebft k\u1ebf<\/a> ri\u00eang cho m\u1ee5c \u0111\u00edch ph\u00f2ng tr\u1ed9m \u0111\u1ed1i v\u1edbi nh\u00e0 \u1edf, c\u00f2n c\u00f3 l\u1eafp m\u00e1y vi t\u00ednh. M\u1ed9t khi c\u00f3 k\u1ebb gian \u0111\u1ed9t nh\u1eadp v\u00e0o khu c\u1ea3nh gi\u1edbi, c\u00e1i c\u1ea3m bi\u1ebfn h\u1ed3ng ngo\u1ea1i li\u1ec1n l\u1eadp t\u1ee9c truy\u1ec1n ra t\u00edn hi\u1ec7u \u0111i\u1ec7n, \u0111\u01b0a v\u00e0o m\u00e1y vi t\u00ednh, n\u1ed1i th\u00f4ng m\u00e1y g\u1ecdi s\u1ed1 t\u1ef1 \u0111\u1ed9ng, d\u00f9ng ti\u1ebfng n\u00f3i \u0111\u00e3 ghi \u00e2m s\u1eb5n \u0111\u1ec3 g\u1ecdi m\u00e1y nh\u1eafn tin ho\u1eb7c \u0111i\u1ec7n tho\u1ea1i di \u0111\u1ed9ng c\u1ee7a ng\u01b0\u1eddi ch\u1ee7 \u0111ang \u1edf ngo\u00e0i ng\u00f4i nh\u00e0, \u0111\u1ed3ng th\u1eddi g\u1ecdi s\u1ed1 \u0111i\u1ec7n tho\u1ea1i b\u00e1o \u0111\u1ed9ng c\u1ee7a S\u1edf C\u00f4ng an.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">T\u1eeb kh\u00f3a: C\u00e1i c\u1ea3nh b\u00e1o; C\u00e1i c\u1ea3m bi\u1ebfn h\u1ed3ng ngo\u1ea1i.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n\n\n\n\n\n\n","protected":false},"excerpt":{"rendered":"<p>\u1ede nh\u1eefng n\u01a1i quan tr\u1ecdng nh\u01b0 ch\u1ed7 c\u1ea5t gi\u1eef ti\u1ec1n nong, v\u00e0ng b\u1ea1c, nh\u00e0 kho hi\u1ec7u bu\u00f4n, l\u01b0u tr\u1eef h\u1ed3 s\u01a1 c\u01a1 m\u1eadt v.v., n\u1ebfu c\u00f3 k\u1ebb gian \u0111\u1ed9t nhi\u00ean l\u1ebbn v\u00e0o, chu\u00f4ng c\u1ea3nh b\u00e1o ph\u00f2ng tr\u1ed9m li\u1ec1n l\u1eadp t\u1ee9c t\u1ef1 \u0111\u1ed9ng k\u00eau: \u0111\u00e8n \u0111\u1ecf nh\u00e1y s\u00e1ng li\u00ean h\u1ed3i, c\u00f2i b\u00e1o \u0111\u1ed9ng r\u00fa l\u00ean \u0111inh [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_disable_autopaging":false},"categories":[15,7],"tags":[],"class_list":["post-5916","post","type-post","status-publish","format-standard","hentry","category-hoi-dap-khoa-hoc","category-vat-ly"],"_links":{"self":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/5916","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/comments?post=5916"}],"version-history":[{"count":0,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/5916\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/media?parent=5916"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/categories?post=5916"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/tags?post=5916"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}