{"id":19671,"date":"2015-12-25T12:12:43","date_gmt":"2015-12-25T05:12:43","guid":{"rendered":"https:\/\/banbientan.com\/?p=19671"},"modified":"2015-12-25T12:12:43","modified_gmt":"2015-12-25T05:12:43","slug":"cau-tao-cam-bien-nhiet-do","status":"publish","type":"post","link":"https:\/\/hunglong.banbientan.com\/?p=19671","title":{"rendered":"C\u1ea5u t\u1ea1o c\u1ea3m bi\u1ebfn nhi\u1ec7t \u0111\u1ed9"},"content":{"rendered":"<h3><strong>C\u1ea5u t\u1ea1o c\u00e1c c\u1ea3m bi\u1ebfn \u0111o nhi\u1ec7t \u0111\u1ed9<\/strong><\/h3>\n<p>Tr\u01b0\u1edbc ti\u00ean, c\u1ea3m bi\u1ebfn l\u00e0 g\u00ec: C\u1ea3m bi\u1ebfn l\u00e0 thi\u1ebft b\u1ecb d\u00f9ng \u0111\u1ec3 \u0111o, \u0111\u1ebfm, c\u1ea3m nh\u1eadn,\u2026c\u00e1c \u0111\u1ea1i l\u01b0\u1ee3ng v\u1eadt l\u00fd kh\u00f4ng \u0111i\u1ec7n th\u00e0nh c\u00e1c t\u00edn hi\u1ec7u \u0111i\u1ec7n. V\u00ed d\u1ee5: Nhi\u1ec7t \u0111\u1ed9 l\u00e0 1 \u0111\u1ea1i l\u01b0\u1ee3ng kh\u00f4ng li\u00ean quan \u0111\u1ebfn \u0111i\u1ec7n ch\u00fang ta ph\u1ea3i chuy\u1ec3n n\u00f3 v\u1ec1 1 \u0111\u1ea1i l\u01b0\u1ee3ng kh\u00e1c ( \u0111i\u1ec7n tr\u1edf, \u0111i\u1ec7n \u00e1p ) \u0111\u1ec3 ph\u00f9 h\u1ee3p v\u1edbi c\u00e1c c\u01a1 c\u1ea5u \u0111i\u1ec7n t\u1eed.<br \/>\nC\u00e1c c\u1ea3m bi\u1ebfn th\u01b0\u1eddng d\u00f9ng trong HVAC: C\u1ea3m bi\u1ebfn nhi\u1ec7t, \u00e1p su\u1ea5t, \u0111\u1ed9 \u1ea9m, m\u1ee9c n\u01b0\u1edbc, l\u01b0u l\u01b0\u1ee3ng gi\u00f3, l\u01b0u l\u01b0\u1ee3ng kh\u00ed, \u0111o n\u1ed3ng \u0111\u1ed9 h\u00f3a ch\u1ea5t trong n\u01b0\u1edbc, CO2, kh\u00f3i, \u2026.<br \/>\n<strong>C\u1ea2M BI\u1ebeN \u0110O NHI\u1ec6T \u0110\u1ed8.<\/strong><br \/>\nNhi\u1ec7t \u0111\u1ed9 t\u1eeb m\u00f4i tr\u01b0\u1eddng s\u1ebd \u0111\u01b0\u1ee3c c\u1ea3m bi\u1ebfn h\u1ea5p thu, t\u1ea1i \u0111\u00e2y t\u00f9y theo c\u01a1 c\u1ea5u c\u1ee7a c\u1ea3m bi\u1ebfn s\u1ebd bi\u1ebfn \u0111\u1ea1i l\u01b0\u1ee3ng nhi\u1ec7t n\u00e0y th\u00e0nh m\u1ed9t \u0111\u1ea1i l\u01b0\u1ee3ng \u0111i\u1ec7n n\u00e0o \u0111\u00f3. Nh\u01b0 th\u1ebf m\u1ed9t y\u1ebfu t\u1ed1 h\u1ebft s\u1ee9c quan tr\u1ecdng \u0111\u00f3 l\u00e0 \u201c nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng c\u1ea7n \u0111o\u201d v\u00e0 \u201cnhi\u1ec7t \u0111\u1ed9 c\u1ea3m nh\u1eadn c\u1ee7a c\u1ea3m bi\u1ebfn\u201d. C\u1ee5 th\u1ec3 \u0111i\u1ec1u n\u00e0y l\u00e0: C\u00e1c lo\u1ea1i c\u1ea3m bi\u1ebfn m\u00e0 c\u00e1c b\u1ea1n tr\u00f4ng th\u1ea5y n\u00f3 \u0111\u1ec1u l\u00e0 c\u00e1i v\u1ecf b\u1ea3o v\u1ec7, ph\u1ea7n t\u1eed c\u1ea3m bi\u1ebfn n\u1eb1m b\u00ean trong c\u00e1i v\u1ecf n\u00e0y ( b\u00e1n d\u1eabn, l\u01b0\u1ee1ng kim\u2026.) do \u0111\u00f3 vi\u1ec7c \u0111o c\u00f3 ch\u00ednh x\u00e1c hay kh\u00f4ng t\u00f9y thu\u1ed9c v\u00e0o vi\u1ec7c truy\u1ec1n nhi\u1ec7t t\u1eeb m\u00f4i tr\u01b0\u1eddng v\u00e0o \u0111\u1ebfn ph\u1ea7n t\u1eed c\u1ea3m bi\u1ebfn t\u1ed5n th\u1ea5t bao nhi\u00eau ( 1 trong nh\u1eefng y\u1ebfu t\u1ed1 quy\u1ebft \u0111\u1ecbnh gi\u00e1 c\u1ea3m bi\u1ebfn nhi\u1ec7t ).<br \/>\n-M\u1ed9t nguy\u00ean t\u1eafc \u0111\u1eb7t ra l\u00e0: T\u0103ng c\u01b0\u1eddng trao \u0111\u1ed5i nhi\u1ec7t gi\u1eefa c\u1ea3m bi\u1ebfn v\u00e0 m\u00f4i tr\u01b0\u1eddng c\u1ea7n \u0111o.<br \/>\n<strong>1, PH\u00c2N LO\u1ea0I C\u1ea2M BI\u1ebeN NHI\u1ec6T.<\/strong><\/p>\n<ul>\n<li>C\u1eb7p nhi\u1ec7t \u0111i\u1ec7n ( Thermocouple ).<\/li>\n<li>Nhi\u1ec7t \u0111i\u1ec7n tr\u1edf ( RTD-resitance temperature detector ).<\/li>\n<li>Thermistor.<\/li>\n<li>B\u00e1n d\u1eabn ( Diode, IC ,\u2026.).<\/li>\n<li>Ngo\u00e0i ra c\u00f2n c\u00f3 lo\u1ea1i \u0111o nhi\u1ec7t kh\u00f4ng ti\u1ebfp x\u00fac ( h\u1ecfa k\u1ebf- Pyrometer ). D\u00f9ng h\u1ed3ng ngo\u1ea1i hay lazer.<\/li>\n<\/ul>\n<p><strong>A.1. C\u1eb6P NHI\u1ec6T \u0110I\u1ec6N ( Thermocouples ).<\/strong><br \/>\n<a href=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/can-J.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-19672\" src=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/can-J.png\" alt=\"can J\" width=\"270\" height=\"143\" \/><\/a><a href=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/Thermocouple.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-19673\" src=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/Thermocouple.jpg\" alt=\"Thermocouple\" width=\"389\" height=\"144\" \/><\/a><\/p>\n<ul>\n<li>C\u1ea5u t\u1ea1o: G\u1ed3m 2 ch\u1ea5t li\u1ec7u kim lo\u1ea1i kh\u00e1c nhau, h\u00e0n d\u00ednh m\u1ed9t \u0111\u1ea7u.<img loading=\"lazy\" decoding=\"async\" class=\"wp-image-19674 alignright\" src=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/can-nhiet.jpg\" alt=\"can nhiet\" width=\"246\" height=\"246\" \/><\/li>\n<li>Nguy\u00ean l\u00fd: Nhi\u1ec7t \u0111\u1ed9 thay \u0111\u1ed5i cho ra s\u1ee9c \u0111i\u1ec7n \u0111\u1ed9ng thay \u0111\u1ed5i ( mV).<\/li>\n<li>\u01afu \u0111i\u1ec3m: B\u1ec1n, \u0111o nhi\u1ec7t \u0111\u1ed9 cao.<\/li>\n<li>Khuy\u1ebft \u0111i\u1ec3m: Nhi\u1ec1u y\u1ebfu t\u1ed1 \u1ea3nh h\u01b0\u1edfng l\u00e0m sai s\u1ed1. \u0110\u1ed9 nh\u1ea1y kh\u00f4ng cao.<\/li>\n<li>Th\u01b0\u1eddng d\u00f9ng: L\u00f2 nhi\u1ec7t, m\u00f4i tr\u01b0\u1eddng kh\u1eaft nghi\u1ec7t, \u0111o nhi\u1ec7t nh\u1edbt m\u00e1y n\u00e9n,\u2026<\/li>\n<li>T\u1ea7m \u0111o: -100 D.C &lt;1400 \u0111\u1ed9 C<\/li>\n<li>G\u1ed3m 2 d\u00e2y kim lo\u1ea1i kh\u00e1c nhau \u0111\u01b0\u1ee3c h\u00e0n d\u00ednh 1 \u0111\u1ea7u g\u1ecdi l\u00e0 \u0111\u1ea7u n\u00f3ng ( hay \u0111\u1ea7u \u0111o), hai \u0111\u1ea7u c\u00f2n l\u1ea1i g\u1ecdi l\u00e0 \u0111\u1ea7u l\u1ea1nh ( hay l\u00e0 \u0111\u1ea7u chu\u1ea9n ). Khi c\u00f3 s\u1ef1 ch\u00eanh l\u1ec7ch nhi\u1ec7t \u0111\u1ed9 gi\u1eefa \u0111\u1ea7u n\u00f3ng v\u00e0 \u0111\u1ea7u l\u1ea1nh th\u00ec s\u1ebd ph\u00e1t sinh 1 s\u1ee9c \u0111i\u1ec7n \u0111\u1ed9ng V t\u1ea1i \u0111\u1ea7u l\u1ea1nh. M\u1ed9t v\u1ea5n \u0111\u1ec1 \u0111\u1eb7t ra l\u00e0 ph\u1ea3i \u1ed5n \u0111\u1ecbnh v\u00e0 \u0111o \u0111\u01b0\u1ee3c nhi\u1ec7t \u0111\u1ed9 \u1edf \u0111\u1ea7u l\u1ea1nh, \u0111i\u1ec1u n\u00e0y t\u00f9y thu\u1ed9c r\u1ea5t l\u1edbn v\u00e0o ch\u1ea5t li\u1ec7u. Do v\u1eady m\u1edbi cho ra c\u00e1c ch\u1ee7ng lo\u1ea1i c\u1eb7p nhi\u1ec7t \u0111\u1ed9, m\u1ed7i lo\u1ea1i cho ra 1 s\u1ee9c \u0111i\u1ec7n \u0111\u1ed9ng kh\u00e1c nhau: E, J, K, R, S, T. C\u00e1c b\u1ea1n l\u01b0u \u00fd \u0111i\u1ec1u n\u00e0y \u0111\u1ec3 ch\u1ecdn \u0111\u1ea7u d\u00f2 v\u00e0 b\u1ed9 \u0111i\u1ec1u khi\u1ec3n cho th\u00edch h\u1ee3p.<\/li>\n<li>D\u00e2y c\u1ee7a c\u1eb7p nhi\u1ec7t \u0111i\u1ec7n th\u00ec kh\u00f4ng d\u00e0i \u0111\u1ec3 n\u1ed1i \u0111\u1ebfn b\u1ed9 \u0111i\u1ec1u khi\u1ec3n, y\u1ebfu t\u1ed1 d\u1eabn \u0111\u1ebfn kh\u00f4ng ch\u00ednh x\u00e1c l\u00e0 ch\u1ed5 n\u00e0y, \u0111\u1ec3 gi\u1ea3i quy\u1ebft \u0111i\u1ec1u n\u00e0y ch\u00fang ta ph\u1ea3i b\u00f9 tr\u1eeb cho n\u00f3 ( offset tr\u00ean b\u1ed9 \u0111i\u1ec1u khi\u1ec3n ).<\/li>\n<\/ul>\n<p><strong>L\u01b0u \u00fd khi s\u1eed d\u1ee5ng:<\/strong><\/p>\n<ul>\n<li>T\u1eeb nh\u1eefng y\u1ebfu t\u1ed1 tr\u00ean khi s\u1eed d\u1ee5ng lo\u1ea1i c\u1ea3m bi\u1ebfn n\u00e0y ch\u00fang ta l\u01b0u \u00fd l\u00e0 kh\u00f4ng n\u00ean n\u1ed1i th\u00eam d\u00e2y ( v\u00ec t\u00edn hi\u1ec7u cho ra l\u00e0 mV n\u1ed1i s\u1ebd suy hao r\u1ea5t nhi\u1ec1u ). C\u1ecdng d\u00e2y c\u1ee7a c\u1ea3m bi\u1ebfn n\u00ean \u0111\u1ec3 th\u00f4ng tho\u00e1ng ( \u0111\u1eebng cho c\u1ecdng d\u00e2y n\u00e0y d\u00ednh v\u00e0o m\u00f4i tr\u01b0\u1eddng \u0111o ). Cu\u1ed1i c\u00f9ng l\u00e0 n\u00ean ki\u1ec3m tra c\u1ea9n th\u1eadn vi\u1ec7c Offset thi\u1ebft b\u1ecb.<\/li>\n<li>L\u01b0u \u00fd: V\u00ec t\u00edn hi\u1ec7u cho ra l\u00e0 \u0111i\u1ec7n \u00e1p ( c\u00f3 c\u1ef1c \u00e2m v\u00e0 d\u01b0\u01a1ng ) do v\u1eady c\u1ea7n ch\u00fa \u00fd k\u00ed hi\u1ec7u \u0111\u1ec3 l\u1eafp \u0111\u1eb7t v\u00e0o b\u1ed9 khu\u1ebfch \u0111\u1ea1i cho \u0111\u00fang.<\/li>\n<\/ul>\n<p><strong>A.2. NHI\u1ec6T\u00a0\u0110I\u1ec6N TR\u1ede\u00a0( RTD-resitance temperature detector ).<\/strong><br \/>\nC\u1ea5u t\u1ea1o c\u1ee7a nhi\u1ec7t \u0111i\u1ec7n tr\u1edf RTD<br \/>\n<a href=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/RTD-resitance-temperature-detector.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-19676\" src=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/RTD-resitance-temperature-detector.jpg\" alt=\"RTD-resitance temperature detector\" width=\"325\" height=\"87\" \/><\/a><a href=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/RTD-resitance-temperature-detector-1.gif\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-19675\" src=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/RTD-resitance-temperature-detector-1.gif\" alt=\"RTD-resitance temperature detector 1\" width=\"334\" height=\"133\" \/><\/a><\/p>\n<ul>\n<li>C\u1ea5u t\u1ea1o c\u1ee7a RTD g\u1ed3m c\u00f3 d\u00e2y kim lo\u1ea1i l\u00e0m t\u1eeb: \u0110\u1ed3ng, Nikel, Platinum,\u2026\u0111\u01b0\u1ee3c qu\u1ea5n t\u00f9y theo h\u00ecnh d\u00e1ng c\u1ee7a \u0111\u1ea7u \u0111o. Khi nhi\u1ec7t \u0111\u1ed9 thay \u0111\u1ed5i \u0111i\u1ec7n tr\u1edf gi\u1eefa hai \u0111\u1ea7u d\u00e2y kim lo\u1ea1i n\u00e0y s\u1ebd thay \u0111\u1ed5i, v\u00e0 t\u00f9y ch\u1ea5t li\u1ec7u kim lo\u1ea1i s\u1ebd c\u00f3 \u0111\u1ed9 tuy\u1ebfn t\u00ednh trong m\u1ed9t kho\u1ea3ng nhi\u1ec7t \u0111\u1ed9 nh\u1ea5t \u0111\u1ecbnh.Ph\u1ed5 bi\u1ebfn nh\u1ea5t c\u1ee7a RTD l\u00e0 lo\u1ea1i c\u1ea3m bi\u1ebfn Pt, \u0111\u01b0\u1ee3c l\u00e0m t\u1eeb Platinum. Platinum c\u00f3 \u0111i\u1ec7n tr\u1edf su\u1ea5t cao, ch\u1ed1ng oxy h\u00f3a, \u0111\u1ed9 nh\u1ea1y cao, d\u1ea3i nhi\u1ec7t \u0111o \u0111\u01b0\u1ee3c d\u00e0i. Th\u01b0\u1eddng c\u00f3 c\u00e1c lo\u1ea1i: 100, 200, 500, 1000 ohm t\u1ea1i 0 D.C. \u0110i\u1ec7n tr\u1edf c\u00e0ng cao th\u00ec \u0111\u1ed9 nh\u1ea1y nhi\u1ec7t c\u00e0ng cao.<\/li>\n<li>RTD th\u01b0\u1eddng c\u00f3 lo\u1ea1i 2 d\u00e2y, 3 d\u00e2y v\u00e0 4 d\u00e2y.<\/li>\n<\/ul>\n<p><a href=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/rtdproducts.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-19677\" src=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/rtdproducts.jpg\" alt=\"rtdproducts\" width=\"592\" height=\"400\" \/><\/a><br \/>\nL\u01b0u \u00fd khi s\u1eed d\u1ee5ng:<\/p>\n<ul>\n<li>Lo\u1ea1i RTD 4 d\u00e2y gi\u1ea3m \u0111i\u1ec7n tr\u1edf d\u00e2y d\u1eabn \u0111i 1\/2, gi\u00fap h\u1ea1n ch\u1ebf sai s\u1ed1.<\/li>\n<li>C\u00e1ch s\u1eed d\u1ee5ng c\u1ee7a RTD kh\u00e1 d\u1ec5 ch\u1ecbu h\u01a1n so v\u1edbi Thermocouple. Ch\u00fang ta c\u00f3 th\u1ec3 n\u1ed1i th\u00eam d\u00e2y cho lo\u1ea1i c\u1ea3m bi\u1ebfn n\u00e0y ( h\u00e0n k\u0129, ch\u1ea5t l\u01b0\u1ee3ng d\u00e2y t\u1ed1t, c\u00f3 ch\u1ed1ng nhi\u1ec5u ) v\u00e0 c\u00f3 th\u1ec3 \u0111o test b\u1eb1ng VOM \u0111\u01b0\u1ee3c.<\/li>\n<li>V\u00ec l\u00e0 bi\u1ebfn thi\u00ean \u0111i\u1ec7n tr\u1edf n\u00ean kh\u00f4ng quan t\u00e2m \u0111\u1ebfn chi\u1ec1u \u0111\u1ea5u d\u00e2y.<\/li>\n<\/ul>\n<p><strong>\u00a0A.3. THERMISTOR<\/strong><br \/>\n<a href=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/THERMISTOR-1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-19679\" src=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/THERMISTOR-1.jpg\" alt=\"THERMISTOR 1\" width=\"296\" height=\"197\" \/><\/a> <a href=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/THERMISTOR.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-19678\" src=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/THERMISTOR.jpg\" alt=\"THERMISTOR\" width=\"235\" height=\"204\" \/><\/a><br \/>\nC\u1ea5u t\u1ea1o: L\u00e0m t\u1eeb h\u1ed5n h\u1ee3p c\u00e1c oxid kim lo\u1ea1i: mangan, nickel, cobalt,\u2026<br \/>\nNguy\u00ean l\u00fd: Thay \u0111\u1ed5i \u0111i\u1ec7n tr\u1edf khi nhi\u1ec7t \u0111\u1ed9 thay \u0111\u1ed5i.<br \/>\n\u01afu \u0111i\u1ec3m: B\u1ec1n, r\u1ebd ti\u1ec1n, d\u1ec5 ch\u1ebf t\u1ea1o.<br \/>\nKhuy\u1ebft \u0111i\u1ec3m: D\u00e3y tuy\u1ebfn t\u00ednh h\u1eb9p.<br \/>\nTh\u01b0\u1eddng d\u00f9ng: L\u00e0m c\u00e1c ch\u1ee9c n\u0103ng b\u1ea3o v\u1ec7, \u00e9p v\u00e0o cu\u1ed9n d\u00e2y \u0111\u1ed9ng c\u01a1, m\u1ea1ch \u0111i\u1ec7n t\u1eed.<br \/>\nT\u1ea7m \u0111o: 50 &lt;150 \u0111\u1ed9 C<br \/>\n<em><strong>C\u1ea5u t\u1ea1o Thermistor.<\/strong><\/em><\/p>\n<ul>\n<li>Thermistor \u0111\u01b0\u1ee3c c\u1ea5u t\u1ea1o t\u1eeb h\u1ed5n h\u1ee3p c\u00e1c b\u1ed9t ocid. C\u00e1c b\u1ed9t n\u00e0y \u0111\u01b0\u1ee3c h\u00f2a tr\u1ed9n theo t\u1ec9 l\u1ec7 v\u00e0 kh\u1ed1i l\u01b0\u1ee3ng nh\u1ea5t \u0111\u1ecbnh sau \u0111\u00f3 \u0111\u01b0\u1ee3c n\u00e9n ch\u1eb7t v\u00e0 nung \u1edf nhi\u1ec7t \u0111\u1ed9 cao. V\u00e0 m\u1ee9c \u0111\u1ed9 d\u1eabn \u0111i\u1ec7n c\u1ee7a h\u1ed5n h\u1ee3p n\u00e0y s\u1ebd thay \u0111\u1ed5i khi nhi\u1ec7t \u0111\u1ed9 thay \u0111\u1ed5i.<\/li>\n<li>C\u00f3 hai lo\u1ea1i thermistor: H\u1ec7 s\u1ed1 nhi\u1ec7t d\u01b0\u01a1ng PTC- \u0111i\u1ec7n tr\u1edf t\u0103ng theo nhi\u1ec7t \u0111\u1ed9; H\u1ec7 s\u1ed1 nhi\u1ec7t \u00e2m NTC \u2013 \u0111i\u1ec7n tr\u1edf gi\u1ea3m theo nhi\u1ec7t \u0111\u1ed9. Th\u01b0\u1eddng d\u00f9ng nh\u1ea5t l\u00e0 lo\u1ea1i NTC.<\/li>\n<li>Thermistor ch\u1ec9 tuy\u1ec3n t\u00ednh trong kho\u1ea3ng nhi\u1ec7t \u0111\u1ed9 nh\u1ea5t \u0111\u1ecbnh 50-150 \u0111\u1ed9 C do v\u1eady ng\u01b0\u1eddi ta \u00edt d\u00f9ng \u0111\u1ec3 d\u00f9ng l\u00e0m c\u1ea3m bi\u1ebfn \u0111o nhi\u1ec7t. Ch\u1ec9 s\u1eed d\u1ee5ng trong c\u00e1c m\u1ee5c \u0111\u00edch b\u1ea3o v\u1ec7, ng\u1eaft nhi\u1ec7t, c\u00e1c b\u00e1c nh\u00e0 ta th\u01b0\u1eddng g\u1ecdi l\u00e0 T\u1eb9t-m\u00edt. C\u00e1i Block l\u1ea1nh n\u00e0o c\u0169ng c\u00f3 m\u1ed9t v\u00e0i b\u1ed9 g\u1eafn ch\u1eb7t v\u00e0o cu\u1ed9n d\u00e2y \u0111\u1ed9ng c\u01a1.<\/li>\n<\/ul>\n<p>L\u01b0u \u00fd khi s\u1eed d\u1ee5ng:<\/p>\n<ul>\n<li>T\u00f9y v\u00e0o nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng n\u00e0o m\u00e0 ch\u1ecdn Thermistor cho th\u00edch h\u1ee3p, l\u01b0u \u00fd hai lo\u1ea1i PTC v\u00e0 NTC ( g\u1ecdi n\u00f4m na l\u00e0 th\u01b0\u1eddng \u0111\u00f3ng\/ th\u01b0\u1eddng h\u1edf ) C\u00f3 th\u1ec3 test d\u1ec5 d\u00e0ng v\u1edbi \u0111\u1ed3ng h\u1ed3 VOM.<\/li>\n<li>N\u00ean \u00e9p ch\u1eb7t v\u00e0o b\u1ec1 m\u1eb7t c\u1ea7n \u0111o.<\/li>\n<li>Tr\u00e1nh l\u00e0m h\u1ecfng v\u1ecf b\u1ea3o v\u1ec7.<\/li>\n<li>V\u00ec bi\u1ebfn thi\u00ean \u0111i\u1ec7n tr\u1edf n\u00ean kh\u00f4ng quan t\u00e2m chi\u1ec1u \u0111\u1ea5u d\u00e2y.<\/li>\n<\/ul>\n<p><strong>A.4. B\u00c1N D\u1eaaN<\/strong><br \/>\n<a href=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/can-nhiet-ban-dan.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-19680\" src=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/can-nhiet-ban-dan.jpg\" alt=\"can nhiet ban dan\" width=\"270\" height=\"225\" \/><\/a> <img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-19682\" src=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/lm35.jpg\" alt=\"lm35\" width=\"138\" height=\"225\" \/><a href=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/lm35-1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-19681\" src=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/lm35-1.jpg\" alt=\"lm35 1\" width=\"215\" height=\"224\" \/><\/a><\/p>\n<ul>\n<li>C\u1ea5u t\u1ea1o: L\u00e0m t\u1eeb c\u00e1c lo\u1ea1i ch\u1ea5t b\u00e1n d\u1eabn.<\/li>\n<li>Nguy\u00ean l\u00fd: S\u1ef1 ph\u00e2n c\u1ef1c c\u1ee7a c\u00e1c ch\u1ea5t b\u00e1n d\u1eabn b\u1ecb \u1ea3nh h\u01b0\u1edfng b\u1edfi nhi\u1ec7t \u0111\u1ed9.<\/li>\n<li>\u01afu \u0111i\u1ec3m: R\u1ebd ti\u1ec1n, d\u1ec5 ch\u1ebf t\u1ea1o, \u0111\u1ed9 nh\u1ea1y cao, ch\u1ed1ng nhi\u1ec5u t\u1ed1t, m\u1ea1ch x\u1eed l\u00fd \u0111\u01a1n gi\u1ea3n.<\/li>\n<li>Khuy\u1ebft \u0111i\u1ec3m: Kh\u00f4ng ch\u1ecbu nhi\u1ec7t \u0111\u1ed9 cao, k\u00e9m b\u1ec1n.<\/li>\n<li>Th\u01b0\u1eddng d\u00f9ng: \u0110o nhi\u1ec7t \u0111\u1ed9 kh\u00f4ng kh\u00ed, d\u00f9ng trong c\u00e1c thi\u1ebft b\u1ecb \u0111o, b\u1ea3o v\u1ec7 c\u00e1c m\u1ea1ch \u0111i\u1ec7n t\u1eed.<\/li>\n<li>T\u1ea7m \u0111o: -50 &lt;150 \u0111\u1ed9 C<\/li>\n<li>C\u1ea3m bi\u1ebfn nhi\u1ec7t B\u00e1n D\u1eabn l\u00e0 nh\u1eefng lo\u1ea1i c\u1ea3m bi\u1ebfn \u0111\u01b0\u1ee3c ch\u1ebf t\u1ea1o t\u1eeb nh\u1eefng ch\u1ea5t b\u00e1n d\u1eabn. C\u00f3 c\u00e1c lo\u1ea1i nh\u01b0 Diode, Transistor, IC. Nguy\u00ean l\u00fd c\u1ee7a ch\u00fang l\u00e0 d\u1ef1a tr\u00ean m\u1ee9c \u0111\u1ed9 ph\u00e2n c\u1ef1c c\u1ee7a c\u00e1c l\u1edbp P-N tuy\u1ebfn t\u00ednh v\u1edbi nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng. Ng\u00e0y nay v\u1edbi s\u1ef1 ph\u00e1t tri\u1ec3n c\u1ee7a ng\u00e0nh c\u00f4ng ngh\u1ec7 b\u00e1n d\u1eabn \u0111\u00e3 cho ra \u0111\u1eddi r\u1ea5t nhi\u1ec1u lo\u1ea1i c\u1ea3m bi\u1ebfn nhi\u1ec7t v\u1edbi s\u1ef1 t\u00edch h\u1ee3p c\u1ee7a nhi\u1ec1u \u01b0u \u0111i\u1ec3m: \u0110\u1ed9 ch\u00ednh x\u00e1c cao, ch\u1ed1ng nhi\u1ec5u t\u1ed1t, ho\u1ea1t \u0111\u1ed9ng \u1ed5n \u0111\u1ecbnh, m\u1ea1ch \u0111i\u1ec7n x\u1eed l\u00fd \u0111\u01a1n gi\u1ea3n, r\u1ebd ti\u1ec1n,\u2026.<\/li>\n<li>Ta d\u1ec5 d\u00e0ng b\u1eaft g\u1eb7p c\u00e1c c\u1ea3m bi\u1ebfn lo\u1ea1i n\u00e0y d\u01b0\u1edbi d\u1ea1ng diode ( h\u00ecnh d\u00e1ng t\u01b0\u01a1ng t\u1ef1 Pt100), c\u00e1c lo\u1ea1i IC nh\u01b0: LM35, LM335, LM45. Nguy\u00ean l\u00fd c\u1ee7a ch\u00fang l\u00e0 nhi\u1ec7t \u0111\u1ed9 thay \u0111\u1ed5i s\u1ebd cho ra \u0111i\u1ec7n \u00e1p thay \u0111\u1ed5i. \u0110i\u1ec7n \u00e1p n\u00e0y \u0111\u01b0\u1ee3c ph\u00e2n \u00e1p t\u1eeb m\u1ed9t \u0111i\u1ec7n \u00e1p chu\u1ea9n c\u00f3 trong m\u1ea1ch.<\/li>\n<\/ul>\n<p>G\u1ea7n \u0111\u00e2y c\u00f3 cho ra \u0111\u1eddi IC c\u1ea3m bi\u1ebfn nhi\u1ec7t cao c\u1ea5p, ch\u00fang h\u1ed5 tr\u1ee3 lu\u00f4n c\u1ea3 chu\u1ea9n truy\u1ec1n th\u00f4ng I2C ( DS18B20 ) m\u1edf ra m\u1ed9t xu h\u01b0\u1edbng m\u1edbi trong \u201c th\u1ebf gi\u1edbi c\u1ea3m bi\u1ebfn\u201d.<br \/>\n<strong>L\u01b0u \u00fd khi s\u1eed d\u1ee5ng:<\/strong><\/p>\n<ul>\n<li>V\u00ec \u0111\u01b0\u1ee3c ch\u1ebf t\u1ea1o t\u1eeb c\u00e1c th\u00e0nh ph\u1ea7n b\u00e1n d\u1eabn n\u00ean c\u1ea3m bi\u1ebfn nhi\u1ec7t B\u00e1n D\u1eabn k\u00e9m b\u1ec1n, kh\u00f4ng ch\u1ecbu nhi\u1ec7t \u0111\u1ed9 cao. N\u1ebfu v\u01b0\u1ee3t ng\u01b0\u1ee1ng b\u1ea3o v\u1ec7 c\u00f3 th\u1ec3 l\u00e0m h\u1ecfng c\u1ea3m bi\u1ebfn.<\/li>\n<li>C\u1ea3m bi\u1ebfn b\u00e1n d\u1eabn m\u1ed7i lo\u1ea1i ch\u1ec9 tuy\u1ebfn t\u00ednh trong m\u1ed9t gi\u1edbi h\u1ea1n n\u00e0o \u0111\u00f3, ngo\u00e0i d\u1ea3i n\u00e0y c\u1ea3m bi\u1ebfn s\u1ebd m\u1ea5t t\u00e1c d\u1ee5ng. H\u1ebft s\u1ee9c quan t\u00e2m \u0111\u1ebfn t\u1ea7m \u0111o c\u1ee7a lo\u1ea1i c\u1ea3m bi\u1ebfn n\u00e0y \u0111\u1ec3 \u0111\u1ea1t \u0111\u01b0\u1ee3c s\u1ef1 ch\u00ednh x\u00e1c.<\/li>\n<li>Lo\u1ea1i c\u1ea3m bi\u1ebfn n\u00e0y k\u00e9m ch\u1ecbu \u0111\u1ef1ng trong m\u00f4i tr\u01b0\u1eddng kh\u1eafc nghi\u1ec7t: \u1ea8m cao, h\u00f3a ch\u1ea5t c\u00f3 t\u00ednh \u0103n m\u00f2n, rung s\u1ed1c va ch\u1ea1m m\u1ea1nh.<\/li>\n<\/ul>\n<p><strong>A.5. NHI\u1ec6T K\u1ebe B\u1ee8C X\u1ea0 ( c\u00f2n g\u1ecdi l\u00e0 h\u1ecfa k\u1ebf- pyrometer ).<\/strong><br \/>\n<a href=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/pyrometer-thermometer.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-19685\" src=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/pyrometer-thermometer.jpg\" alt=\"pyrometer thermometer\" width=\"280\" height=\"306\" \/><\/a> <a href=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/buc-xa-ke.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-19686\" src=\"https:\/\/banbientan.com\/wp-content\/uploads\/2015\/12\/buc-xa-ke.jpg\" alt=\"buc xa ke\" width=\"330\" height=\"308\" \/><\/a><\/p>\n<ul>\n<li>C\u1ea5u t\u1ea1o: L\u00e0m t\u1eeb m\u1ea1ch \u0111i\u1ec7n t\u1eed, quang h\u1ecdc.<\/li>\n<li>Nguy\u00ean l\u00fd: \u0110o t\u00ednh ch\u1ea5t b\u1ee9c x\u1ea1 n\u0103ng l\u01b0\u1ee3ng c\u1ee7a m\u00f4i tr\u01b0\u1eddng mang nhi\u1ec7t.<\/li>\n<li>\u01afu \u0111i\u1ec3m: D\u00f9ng trong m\u00f4i tr\u01b0\u1eddng kh\u1eafc nghi\u1ec7t, kh\u00f4ng c\u1ea7n ti\u1ebfp x\u00fac v\u1edbi m\u00f4i tr\u01b0\u1eddng \u0111o.<\/li>\n<li>Khuy\u1ebft \u0111i\u1ec3m: \u0110\u1ed9 ch\u00ednh x\u00e1c kh\u00f4ng cao, \u0111\u1eaft ti\u1ec1n.<\/li>\n<li>Th\u01b0\u1eddng d\u00f9ng: L\u00e0m c\u00e1c thi\u1ebft b\u1ecb \u0111o cho l\u00f2 nung.<\/li>\n<li>T\u1ea7m \u0111o: -54 &lt;1000 D.F.<\/li>\n<li>Nhi\u1ec7t k\u1ebf b\u1ee9c x\u1ea1 ( h\u1ecfa k\u1ebf ) l\u00e0 lo\u1ea1i thi\u1ebft b\u1ecb chuy\u00ean d\u1ee5ng d\u00f9ng \u0111\u1ec3 \u0111o nhi\u1ec7t \u0111\u1ed9 c\u1ee7a nh\u1eefng m\u00f4i tr\u01b0\u1eddng m\u00e0 c\u00e1c c\u1ea3m bi\u1ebfn th\u00f4ng th\u01b0\u1eddng kh\u00f4ng th\u1ec3 ti\u1ebfp x\u00fac \u0111\u01b0\u1ee3c ( l\u00f2 nung th\u00e9p, h\u00f3a ch\u1ea5t \u0103n m\u00f2n m\u1ea1nh, kh\u00f3 \u0111\u1eb7t c\u1ea3m bi\u1ebfn).<\/li>\n<li>G\u1ed3m c\u00f3 c\u00e1c lo\u1ea1i: H\u1ecfa k\u1ebf b\u1ee9c x\u1ea1, h\u1ecfa k\u1ebf c\u01b0\u1eddng \u0111\u1ed9 s\u00e1ng, h\u1ecfa k\u1ebf m\u00e0u s\u1eafc. Ch\u00fang ho\u1ea1t \u0111\u1ed9ng d\u1ef1a tr\u00ean nguy\u00ean t\u1eafc c\u00e1c v\u1eadt mang nhi\u1ec7t s\u1ebd c\u00f3 hi\u1ec7n t\u01b0\u1ee3ng b\u1ee9c x\u1ea1 n\u0103ng l\u01b0\u1ee3ng. V\u00e0 n\u0103ng l\u01b0\u1ee3ng b\u1ee9c x\u1ea1 s\u1ebd c\u00f3 m\u1ed9t b\u01b0\u1edbc s\u00f3ng nh\u1ea5t \u0111\u1ecbnh. H\u1ecfa k\u1ebf s\u1ebd thu nh\u1eadn b\u01b0\u1edbc s\u00f3ng n\u00e0y v\u00e0 ph\u00e2n t\u00edch \u0111\u1ec3 cho ra nhi\u1ec7t \u0111\u1ed9 c\u1ee7a v\u1eadt c\u1ea7n \u0111o.<\/li>\n<\/ul>\n<p><strong>L\u01b0u \u00fd khi s\u1eed d\u1ee5ng:<\/strong><br \/>\nT\u00f9y theo th\u00f4ng s\u1ed1 c\u1ee7a nh\u00e0 s\u1ea3n xu\u1ea5t m\u00e0 h\u1ecfa k\u1ebf c\u00f3 c\u00e1c t\u1ea7m \u0111o kh\u00e1c nhau, tuy nhi\u00ean \u0111a s\u1ed1 h\u1ecfa k\u1ebf \u0111o \u1edf kho\u1ea3ng nhi\u1ec7t \u0111\u1ed9 cao. V\u00e0 v\u00ec \u0111\u1eb7c \u0111i\u1ec3m kh\u00f4ng ti\u1ebfp x\u00fac tr\u1ef1c ti\u1ebfp v\u1edbi v\u1eadt c\u1ea7n \u0111o n\u00ean m\u1ee9c \u0111\u1ed9 ch\u00ednh x\u00e1c c\u1ee7a h\u1ecfa k\u1ebf kh\u00f4ng cao, ch\u1ecbu nhi\u1ec1u \u1ea3nh h\u01b0\u1edfng c\u1ee7a m\u00f4i tr\u01b0\u1eddng xung quanh ( g\u00f3c \u0111\u1ed9 \u0111o, rung tay, \u00e1nh s\u00e1ng m\u00f4i tr\u01b0\u1eddng ).<\/p>\n","protected":false},"excerpt":{"rendered":"<p>C\u1ea5u t\u1ea1o c\u00e1c c\u1ea3m bi\u1ebfn \u0111o nhi\u1ec7t \u0111\u1ed9 Tr\u01b0\u1edbc ti\u00ean, c\u1ea3m bi\u1ebfn l\u00e0 g\u00ec: C\u1ea3m bi\u1ebfn l\u00e0 thi\u1ebft b\u1ecb d\u00f9ng \u0111\u1ec3 \u0111o, \u0111\u1ebfm, c\u1ea3m nh\u1eadn,\u2026c\u00e1c \u0111\u1ea1i l\u01b0\u1ee3ng v\u1eadt l\u00fd kh\u00f4ng \u0111i\u1ec7n th\u00e0nh c\u00e1c t\u00edn hi\u1ec7u \u0111i\u1ec7n. V\u00ed d\u1ee5: Nhi\u1ec7t \u0111\u1ed9 l\u00e0 1 \u0111\u1ea1i l\u01b0\u1ee3ng kh\u00f4ng li\u00ean quan \u0111\u1ebfn \u0111i\u1ec7n ch\u00fang ta ph\u1ea3i chuy\u1ec3n n\u00f3 v\u1ec1 [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":19672,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10269],"tags":[13270,13271,13272,13273,13274,13275,13276,13277],"class_list":["post-19671","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bai-4-kiem-soat-nhiet-do","tag-can-nhiet-k","tag-can-nhiet-pt100","tag-cap-nhiet-dien","tag-nhiet-dien-tro","tag-pyrometer-thermometer","tag-resitance-temperature-detector","tag-thermistor","tag-thermocouples"],"_links":{"self":[{"href":"https:\/\/hunglong.banbientan.com\/index.php?rest_route=\/wp\/v2\/posts\/19671","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hunglong.banbientan.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hunglong.banbientan.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hunglong.banbientan.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/hunglong.banbientan.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=19671"}],"version-history":[{"count":0,"href":"https:\/\/hunglong.banbientan.com\/index.php?rest_route=\/wp\/v2\/posts\/19671\/revisions"}],"wp:attachment":[{"href":"https:\/\/hunglong.banbientan.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=19671"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hunglong.banbientan.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=19671"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hunglong.banbientan.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=19671"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}