Thermocouple: qa'ida ta aiki, da na'urar

Akwai m iri-iri na'urorin da kuma hanyoyin auna zafin jiki. Wasu daga cikin su suna amfani da rayuwar yau da kullum, wasu - don wani iri-iri na jiki da bincike, a cikin masana'antu tafiyar matakai da sauran masana'antu.

Wata irin wannan na'urar ne wani thermocouple. Ka'idar aiki na na'urar da kewaye da za a tattauna a cikin wadannan sassan.

The jiki Dalili na thermocouple ayyukansu

The aiki manufa na thermocouples dogara ne a kan saba jiki matakai. Domin da farko lokacin da sakamako, a kan tushen da wanda naúrar aiki, da aka bincika da Jamus masanin kimiyya Thomas Seebeck.

Jigon da sabon abu, wanda yake riƙe da thermocouple mataki manufa kamar haka. A cikin rufaffiyar lantarki kewaye kunsha na biyu daban-daban na conductors, lokacin da fallasa wasu muhalli da zazzabi da wutar lantarki ta taso.

A sakamakon wutar lantarki da kuma na yanayi zazzabi aiki a kan conductors ne a mikakke dogara. Wannan ne, da hakan yawan zafin jiki, da girma da wutar lantarki da generated da wani thermocouple. Kuma tushen a kan wannan manufa na aiki na thermocouple da kuma juriya ma'aunin zafi da sanyio.

A cikinsu daya daga cikin thermocouple lamba ne a batu inda ya zama dole don auna zafin jiki, da shi ne ake kira "zafi." Na biyu lamba, a wasu kalmomi - "sanyi" - a gaban shugabanci. Aikace-aikace don aunawa thermocouples izini kawai a cikin yanayin a lokacin da dakin zafin jiki ne m fiye da ji shafin.

Irin wannan gajeren kewaye aiki na thermocouple, da aiki da ka'ida. Iri thermocouples za a tattauna a gaba sashe.

iri thermocouples

A kowane masana'antu, inda zafin jiki ma'aunai ana buƙatar, yafi amfani thermocouple. A na'ura da kuma aiki iri-iri na naúrar aka nuna a kasa.

Aluminum-Chromel thermocouple

Wadannan thermocouples tsari amfani a mafi yawan lokuta, don samar da wani iri-iri masu auna sigina da kuma bincike da cewa taimaka yawan zafin jiki kula a masana'antu samar.

Su rarrabe ne mun gwada low farashin da kuma wata babbar kewayon da auna zafin jiki. Su ba da damar gyara zafin jiki na daga -200 zuwa 13 000 digiri Celsius.

Shi ne da bai dace ba a yi amfani da wani thermocouple to irin wannan gami a cikin shaguna da kuma high sulfur abubuwa a cikin iska, saboda wannan sinadari adversely rinjayar da biyu da chromium da aluminum, haddasa disturbances a cikin aiki na na'urar.

Chromel-Copel thermocouple

A manufa na mataki na thermocouple, lamba kungiyar wanda aka hada da wadannan gami shi ne guda. Amma wadannan na'urorin aiki mafi yawa a cikin ruwa, ko gaseous yanayi da ciwon tsaka tsaki, wadanda ba lalatattu Properties. A babba zazzabi nuna alama bai wuce 8000 digiri Celsius.

M irin thermocouple, wanda amfani da manufa da aiki bayar da shi don kafa mataki na dumama wani surface, msl, don ganowa da yawan zafin jiki na bude hearth makera ko wani irin Tsarin.

Iron-constantan thermocouple

Wannan hade da lambobi a thermocouple ba kamar yadda na kowa kamar yadda na farko daga cikin nau'in karkashin shawara. The aiki manufa na thermocouples ne guda, amma wannan hade yi kyau a cikin rarefied yanayi. A kalla matakin matakan da zazzabi kada wuce 12,500 digiri Celsius.

Duk da haka, idan zafin jiki fara tashi sama da 7000 da digiri, akwai hadarin keta ji daidaito saboda canje-canje a cikin jiki da kuma sinadaran Properties na baƙin ƙarfe. Akwai ma lokuta lalata na baƙin ƙarfe tuntužar thermocouple a gaban yanayi ruwa tururi.

Platinum-platinum thermocouples

A mafi tsada a yi na thermocouples. Ka'idar aiki ne guda, amma shi ne daban-daban daga takwarorinsu sosai a barga ne kuma abin dogara da zazzabi karatu. Ya rage ji na ƙwarai.

Babban aikace-aikace na wadannan na'urorin - aunawa high yanayin zafi.

Tungsten-rhenium thermocouple

Yana kuma amfani da aunawa sosai high yanayin zafi. Matsakaicin iyaka wanda za a iya kulle ta hanyar da kewaye kai 25 dubu digiri Celsius.

Su yi amfani da bukatar yarda da wasu yanayi. Saboda haka, a lokacin da zazzabi ji wajibi ne don gaba daya kawar da suke kewaye da sararin sama, wanda yana da mummunan tasiri a kan dari a hadawan abu da iskar shaka tsari.

Domin wannan tungsten-rhenium thermocouple mafi yawa ana sanya shi a cikin housings cika da wani inert gas kare su abubuwa.

Sama kowane data kasance thermocouple aka yi nazari, da inji, da manufa na shi dangane da amfani gami. Yanzu dubi wasu daga cikin zane fasali.

yi na thermocouples

Akwai biyu main iri thermocouples kayayyaki.

• Tare da aikace-aikace na insulating Layer. Wannan zane azurta thermocouple aiki na'urar kadaici Layer ta lantarki a halin yanzu. Irin wannan makirci damar yin amfani da wani thermocouple a cikin tsari ba tare da kadaici daga ƙasa ƙofar.

• Ba tare da yin amfani da insulating Layer. Irin wannan thermocouples za a iya haɗa kawai ga aunawa haihuwarka, da bayanai na wanda da babu lamba da ƙasa. Idan wannan yanayin ba hadu, na'urar akwai biyu m rufaffiyar kewaye, inda da karatu samu ta amfani da thermocouple ba zai zama daidai.

Running thermocouple da aikace-aikace

Akwai raba jinsunan wannan na'urar, koma zuwa ga "tafiya". Ka'idar aiki na wani tafiya thermocouple mu yanzu la'akari a more daki-daki.

Wannan zane yana da yafi amfani ga kayyade yawan zafin jiki na karfe billet a lokacin da aiki a juya, milling da sauran irin machining.

Ya kamata a lura cewa a wannan harka zai yiwu in yi amfani da al'ada thermocouple, duk da haka, idan masana'antu tsari na bukatar high ainihin yawan zafin jiki kula, a thermocouple gudu overemphasized.

Lokacin da ake ji wannan hanya da workpiece a gaba na ta lamba abubuwa ne shãfe haske. Sa'an nan, a cikin aiki na billet, wadannan lambobi suna ci gaba da fallasa da aiki kayan aiki ko wasu inji kayan aiki, inda ya isa maha? Ar (wanda shi ne babban kashi a lokacin kau da zazzabi halaye) kamar yadda shi "runs" na lambobin sadarwa.

Wannan sakamako ne yadu a yi amfani da karfe masana'antu.

Fasaha fasali na thermocouples kayayyaki

A yi na aiki karu thermocouple kewaye da aka sanya na biyu karfe lambobi da aka sani da za a yi na daban-daban kayan. Maha? Ar da ake kira "maha? Ar".

Ya kamata a lura da cewa yin fili optionally via spikes. Kawai karkatar da magana, tare da biyu lambobi. Amma irin wannan masana'antu Hanyar ba zai yi wani isasshen matakin na AMINCI, da kuma iya samar da kuskure a lokacin da cire zazzabi halaye.

Idan kana bukatar high zafin jiki ji, soldering karfe an maye gurbinsu da su waldi. Wannan shi ne saboda cewa a mafi yawan lokuta, da solder amfani a connection, yana da wani low narkewa batu da aka hallaka lokacin da ta matakin an wuce.

Makirci, da yi na wanda waldi an amfani, zai iya tsayayya da fadi da zafin jiki da fuska. Amma wannan hanya na connection yana da nasa drawbacks. A ciki tsarin na karfe kan daukan hotuna zuwa high zafin jiki a lokacin waldi iya canza, wanda zai shafi ingancin da bayanai.

Haka kuma, shi ya kamata saka idanu da matsayi na thermocouple lambobi a cikin shakka daga ta aiki. Saboda haka, yana yiwuwa ya canza halaye na karafa a kewaye saboda m muhalli da tasirinsa. Hadawan abu da iskar shaka na iya faruwa ko interdiffusion na kayan. A irin wannan halin da ake ciki shi wajibi ne don maye gurbin aiki na thermocouple kewaye.

Iri maha? Ar thermocouples

Modern masana'antu samar da dama kayayyaki, wanda ake amfani da shi a yi na thermocouples:

• bude maha? ar.

• Makaran maha? Ar.

• wani na rasa maha? ar.

thermocouples fasalin na bude maha? ar ne matalauta jure waje tsoma.

Wadannan nau'o'i guda biyu na Tsarin za a iya amfani da aunawa da yanayin zafi a maƙiya mahalli, za a iya samun yankunan da illa da kan lamba biyu.

Haka kuma, a halin yanzu da masana'antu ne tasowa haihuwarka a kan semiconductor thermocouples samar da fasahar.

ji kuskure

Daidaito na zazzabi halaye samu ta hanyar wani thermocouple dogara a kan abu na lamba kungiyar, kazalika da waje dalilai. A karshen hada da matsin lamba, da bango radiation ko wasu dalilai da za su iya shafar jiki da kuma sinadaran Properties na karafa, wanda yin lambobi.

Daidaito na ji kunshi wadannan aka gyara:

• bazuwar kuskure sa da thermocouple masana'antu siffofin.

• kuskure lalacewa ta hanyar yawan zafin jiki take hakkin "sanyi" lamba;

• kuskure, a cikin hanyar wanda aiki a matsayin waje amo.

• iko inji kuskure.

A abũbuwan amfãni daga yin amfani da thermocouples

A abũbuwan amfãni daga yin amfani da irin wannan na'urorin ya ga yawan zafin jiki kula, ko da kuwa da aikace-aikace, su ne:

• babban rata Manuniya cewa za a iya rubuta wani thermocouple.

• karu thermocouple, wanda shi ne kai tsaye da hannu a cikin kau da karatu za a iya positioned a tsaye lamba tare da aunawa batu;

• sauki aiwatar da masana'antu thermocouples, su ƙarfi da karko na aiki.

Disadvantages na da yawan zafin jiki ji ta amfani da wani thermocouple

A disadvantages da ake ji thermocouples sun hada da:

• Bukatar ci gaba da saka idanu da yawan zafin jiki na "sanyi" thermocouple lamba. Wannan shi ne rarrabe da zane na aunawa kida, wanda da su ne bisa thermocouple. Ka'idar aiki na makirci Narrows iyãwarsa. Su za a iya amfani kawai idan yanayi zazzabi shi ne a kasa da yawan zafin jiki a ma'auni batu.

• Take hakkin da ciki tsarin karafa amfani a yi na thermocouple. Gaskiyar ita ce, saboda da waje yanayi Lambobin rasa su uniformity, wanda ya haddasa kurakurai a cikin zazzabi karatu samar.

• A lokacin da ji na thermocouple lamba kungiyar ne yawanci fallasa su m muhalli tsoma, wanda ya haddasa disturbances a aiki. Wannan sake bukatar da sealing na lambobi, wanda ya haddasa ƙarin goyon baya halin kaka na wannan na'urori masu auna sigina.

• Akwai hadari na daukan hotuna zuwa electromagnetic taguwar ruwa ta thermocouple wanda shiri na samar da wani dogon lamba kungiyar. Yana kuma iya shafar sakamakon ma'aunai.

• A wasu lokuta, da take hakkin ya auku a mikakke dangantaka tsakanin lantarki halin yanzu tasowa a cikin thermocouple kuma yawan zafin jiki a ji shafin. Wannan halin da ake ciki na bukatar wani k kula da na'ura.

ƙarshe

Duk da shortcomings, da hanyar da ji na zazzabi da thermocouples, wanda aka farko ƙirƙira da kuma gwada a cikin karni na 19th, same ta fadi da aikace-aikace a cikin dukkan rassan zamani masana'antu.

Bugu da ƙari, akwai wanzu aikace-aikace inda amfanin thermocouples ne kawai hanyar da samun da yawan zafin jiki data. Kuma karanta wannan abu, ka mayalwaci fahimtar ka'idojin aikinsu.