Isimiso esisebenzayo se-thermometer ye-elekthronikhi

I-thermometer ye-thermoelectric isebenzisa i-thermocouple njengesici sokulinganisa izinga lokushisa ukukala amandla e-thermoelectromotive ahambelana nethempelesha futhi inani lokushisa liboniswa yimitha. Kusetshenziswa kabanzi ukukala izinga lokushisa ebangeni le - 200 ℃ ~ 1300 ℃, futhi ngaphansi kwezimo ezikhethekile, lingalinganisa izinga lokushisa eliphakeme lama-2800 ℃ noma izinga lokushisa eliphansi le-4K. Inezici zesakhiwo esilula, intengo ephansi, ukunemba okuphezulu, nobubanzi besilinganiso sokushisa. Ngoba i-thermocouple iguqula ukushisa kube ugesi ukuze kutholwe, kulula ukukala nokulawula ukushisa, nokukhulisa nokuguqula amasiginali wokushisa. Kufanelekile ukulinganiswa kwebanga elide nokulawula okuzenzakalelayo. Endleleni yokukala izinga lokushisa oxhumana naye, ukusetshenziswa kwama-thermometer we-thermoelectric yikhona okuvame kakhulu.

DS-1
(1) Isilinganiso sesilinganiso sokushisa se-Thermocouple
Umgomo wesilinganiso sokushisa se-thermocouple usekelwe kumphumela we-thermoelectric.
Xhuma abaqhubi u-A no-B bezinto ezimbili ezihlukene ochungechungeni ku-loop evaliwe. Lapho izinga lokushisa loxhumana nabo ababili u-1 no-2 behlukile, uma u-T> T0, kuzokhiqizwa amandla we-thermoelectromotive ku-loop, futhi kuzoba nenani elithile ku-loop. Imisinga emikhulu nemincane, lesi simo sibizwa ngokuthi yi-pyroelectric effect. La mandla asebenzisa amandla omoya yi "Seebeck thermoelectromotive force" eyaziwayo, ebizwa nge "thermoelectromotive force", ebizwa nge-EAB, kanti abaqhubi A no-B babizwa ngama-thermoelectrode. Oxhumana naye 1 uvame ukuhlanganiswa ndawonye, ​​futhi ubekwe endaweni yokukala izinga lokushisa ukuzwa izinga lokushisa elilinganisiwe ngesikhathi sokulinganisa, ngakho-ke kuthiwa ukuphela kokulinganisa (noma ukuphela okushisayo kokuphela kokusebenza). I-junction 2 idinga ukushisa okungaguquguquki, okubizwa ngokuthi yi-reference junction (noma ukuhlangana okubanda). Inzwa ehlanganisa ama-conductor amabili bese iguqula izinga lokushisa libe yi-thermoelectromotive force ibizwa nge-thermocouple.

Amandla we-thermoelectromotive aqukethe amandla wokuxhumana wabaqhubi ababili (amandla wePeltier) namandla okwehluka kwamazinga okushisa komqhubi oyedwa (amandla kaThomson). Ubukhulu bamandla we-thermoelectromotive amandla ahlobene nezakhiwo zezinto ezimbili zokuqhuba kanye nezinga lokushisa lokuhlangana.
Ubuningi be-electron ngaphakathi komqhubi buhlukile. Lapho ama-conductor amabili A no-B anama-electron densities ahlukene athintana, ukusabalala kwe-electron kwenzeka ebusweni bokuxhumana, futhi ama-electron ageleza esuka kumqhubi anamandla amakhulu we-electron aye kumqhubi onamandla amancane. Izinga lokusabalalisa kwe-electron lihlobene nobuningi be-electron yabaqhubi ababili futhi bulingana namazinga okushisa endawo yokuxhumana. Uma kucatshangwa ukuthi ukuminyana kwama-elektroni amahhala abaqhubi be-A no-B yi-NA ne-NB, kanti i-NA> NB, ngenxa yokusakazeka kwe-electron, umqhubi u-A ulahlekelwa ama-electron bese ekhokhiswa kahle, kuyilapho umqhubi B ethola ama-electron bese eba necala elibi, kwakheke ugesi inkambu ebusweni bokuxhumana. Le nsimu kagesi ivimbela ukusabalala kwama-electron, futhi lapho kufinyelelwa ukulingana okunamandla, kwakheka umehluko ozinzile ongaba khona endaweni yokuxhumana, okungukuthi, amandla oxhumana naye, ubukhulu bawo

(8.2-2)

Lapho okuqhubekayo k-Boltzmann, k = 1.38 × 10-23J / K;
e – inani lentengo ye-electron, e = 1.6 × 10-19 C;
T – Ukushisa endaweni yokuxhumana, K;
I-NA, i-NB - yizingqinamba zamahhala zama-elektroni abaqhubi A no-B, ngokulandelana.
Amandla kagesi akhiqizwa umehluko wezinga lokushisa phakathi kwamaphethelo amabili womqhubi abizwa ngokuthi amandla we-thermoelectric. Ngenxa yesilinganiso sokushisa, ukusatshalaliswa kwamandla kwama-electron kuyashintshwa. Ama-electron end (T) aphezulu asezingeni lokushisa azokwedlulela ekugcineni kwezinga lokushisa eliphansi (T0), okwenza ukuphela kokushisa okuphezulu kukhokhiswe kahle ngenxa yokulahleka kwama-electron, futhi ukuphela kokushisa okuphansi kuzokhokhiswa kabi ngenxa yama-electron. Ngakho-ke, umehluko ongaba khona nawo wenziwa emaphethelweni womabili womqhubi ofanayo futhi uvimbela ama-electron ekusakazekeni ukusuka ekugcineni kokushisa okuphezulu kuya ekugcineni kokushisa okuphansi. Ngemuva kwalokho ama-electron ayahlukahluka ukwakha ukulingana okunamandla. Umehluko ongaba khona osungulwe ngalesi sikhathi ubizwa ngokuthi amandla we-thermoelectric noma amandla we-Thomson, ahlobene nokushisa kwe-For

(8.2-3)

JDB-23 (2)

Kwifomula, σ yi-coefficient kaThomson, emele inani lamandla kagesi elenzelwa umehluko wezinga lokushisa elingu-1 ° C, futhi ubukhulu balo buhlobene nezinto ezibonakalayo kanye nezinga lokushisa emaphethelweni womabili.
Isifunda esivaliwe se-thermocouple esakhiwe ngabaqhubi A no-B sinamakhono amabili wokuxhumana eAB (T) ne-eAB (T0) koxhumana nabo ababili, futhi ngenxa yokuthi i-T> T0, kukhona namandla we-thermoelectric komunye wabaqhubi A no-B. inani eliphelele lamandla kagesi ashisayo we-EAB (T, T0) we-loop evaliwe kufanele kube isamba se-algebraic yamandla okuxhumana we-electromotive kanye nomehluko wamazinga okushisa amandla kagesi, okungukuthi:

(8.2-4)

Kwi-thermocouple ekhethiwe, lapho izinga lokushisa eliyisithenjwa lihlala likhona, inani eliphelele le-thermoelectromotive force liba umsebenzi onenani elilodwa lokushisa kwetheminali yokukala T, okungukuthi, i-EAB (T, T0) = f (T). Lesi yisimiso esiyisisekelo sokushisa okulinganisa i-thermocouple.


Isikhathi Iposi: Jun-11-2021