Lub luag haujlwm ntawm thermocouple thiab ua haujlwm txoj cai
Lub luag haujlwm ntawm thermocouple thiab ua haujlwm txoj cai?
Cov thermocouples yog ib qho uas feem ntau siv kub sensing Cheebtsam hauv kev lag luam. Nws qhov ua tau zoo yog: ① ntsuas ntau tshaj qhov ntsuas. Vim yog lub thermocouple ncaj nraim nrog tus kwv ntsuas, ntawm qhov nruab nrab ntawm qhov nruab nrab. ② dav dav ntsuas. Hom thermocouple los ntawm -50 ~ +600 ℃ tuaj yeem ntsuas sab ntawm sab, qee tus thermocouple tau ntsuas ntawm -269 ℃ (xws li kub thiab hlau nickel chrome), mus txog +2800 ℃ (xws li tungsten - rhenium). ③ yooj yim qauv, ib qho yooj yim mus use. Cov thermocouples feem ntau yog tsim los ntawm ob lub xov hlau, thiab tsis txwv los ntawm qhov loj me thiab pib, lub tsho tiv thaiv tsho, uas yooj yim heev rau siv.
1. Kev ntsuas kub thermocouple cov ntsiab lus ntawm ob yam ntaub ntawv ntawm tus neeg xyuas pib lossis semiconductor A thiab B welded ua ke los tsim ib lub voj kaw. Thaum muaj qhov sib txawv ntawm qhov nruab nrab ntawm ob lub ntsiab lus siab 1 thiab 2 ntawm cov neeg sib tw A thiab B, ib qho kev sib txuas ntawm electromotive yog tsim los ntawm lawv, ua rau muaj qhov loj ntawm qhov tam sim no hauv lub voj, uas yog hu ua thermoelectric effect. Thermocouple yog kev siv cov nyhuv ua hauj lwm.
2. Hom thiab cov qauv ntawm cov thermocouples
(1) hom thermocouple feem ntau siv cov thermocouples raug faib ua tus txheem thermocouple thiab tsis-txheem thermocouple ob pawg. Hu ua tus txheej txheem thermocouple yog lub tebchaws tus qauv qhia txog kev sib raug zoo ntawm nws thermoelectric lub zog thiab qhov kub, cia qhov yuam kev, thiab tus qauv thermocouple unified, nws muaj ib qho kev ntsuas khoom siv. Cov thermocouple uas tsis yog standardized nyob rau hauv kev siv ntawm qhov muaj lossis qhov ntau yog tsawg tshaj li tus standardization ntawm thermocouple, feem ntau yog tsis muaj lub rooj cim teeb, tshwj xeeb rau qee lub sij hawm tshwj xeeb, ntsuas. Txij li thaum Lub Ib Hlis 1, 1988, thermocouple thiab thermal tsis ua haujlwm tag nrho ua raws li IEC thoob ntiaj teb cov qauv, thiab tau tso S, B, E, K, R, J, T (piv txwv li, sub tooj) xya tus qauv thermoelectric Txawm yog peb unified tsim ntawm thermocouple.
(2) tus qauv ntawm lub thermocouple Yuav kom ntseeg tau tias kev ruaj ntseg thiab ruaj khov ntawm lub thermocouple, nws cov qauv yuav tsum muaj raws li nram no: ① thermocouple li ntawm ob thermal electrode welding yuav tsum muaj zog; ② ob tug kub electrodes yuav tsum sib txhawv ntawm kev sib cai los tiv thaiv qhov luv luv Circuit Court; ③ nyiaj xaim thiab thermocouple dawb kawg ntawm kev txuas yuav tsum yooj yim thiab txhim khu kev qha; ④ lub tsho tiv thaiv yuav tsum muaj peev xwm xyuas kom meej tias lub thermal electrode thiab cov teeb meem ntawm cov teeb meem raug muab cais tawm.
3. Cov thermocouple txias qhov kawg ntawm lub cev Thaum lub thermocouple cov khoom siv feem ntau pheej yig tshaj (tshwj xeeb tshaj yog thaum siv cov hlau zoo), thiab qhov ntsuas qhov ntsuas ntawm qhov ntsuas yog nyob deb, kom txuag cov thermocouple khoom, txo nqi, feem ntau siv nyiaj xaim rau thermoelectric Txawm tias qhov txias kawg (qhov kawg dawb) txuas mus rau ib qho chaw tiv thaiv qhov kub thiab txias, nrog rau qhov ntsuas dav dav. Nws yuav tsum tau taw qhia tias lub luag hauj lwm ntawm lub thermocouple compensation telire tsuas yog siv lub thermal electrode, kom txias kawg ntawm lub thermocouple kom tsiv mus rau qhov chaw tswj ntawm qhov ntsuas dav dav hlau, uas nws tus kheej tsis tau tshem tawm qhov txias hlav kub hloov ntawm lub kub, tsis tuaj yeem them nyiaj raug mob. Yog li, lwm txoj kev kho yuav tsum tau siv los txhawb lub txias qhov siab txias t0 ≠ 0 ℃ ntawm qhov kub thiab txias. Kev siv thermocouple compensation tel yuav tsum xyuam xim rau cov qauv kev sib tw, lub polarity tsis tuaj yeem yuam kev, nyiaj xaim thiab thermocouple kev txuas sab ntawm qhov kub tsis tshaj 100 ℃. Piv txwv: S-hom thermocouple) platinum thiab rhodium 10-platinum thermocouple platinum thiab rhodium 10-platinum thermocouple (S-hom thermocouple) rau cov khoom siv hlau thermocouple precious. Cov tshuaj hu ua "electrode" (SP) yog cov platinum thiab rhodium alloy, uas yog 10% rhodium, 90% platinum, thiab negative (SN) yog platinum ntshiab. Feem ntau hu ua platinum thiab rhodium thermocouple. Qhov ntev thermocouple ntev tshaj plaws ntawm 1300 ℃, lub sij hawm luv tshaj plaws ntawm 1600 ℃. S-hom thermocouple hauv thermocouple series nrog lub siab tshaj plaws, qhov zoo tshaj plaws stability, dav kub kub, ntev lub neej thiab lwm yam zoo. Nws lub cev, tshuaj muaj zog, thermoelectric stability thiab siab oxidation tsis haum, haum rau oxidizing thiab inert cua. Raws li tus S-hom thermocouple tau zoo heev tag nrho kev ua tau zoo, nyob rau hauv txoj kab nrog kev siv thoob ntiaj teb kev ntsuas kub S-hom thermocouple, tau ntev tau siv raws li kev ntsuas kub thoob ntiaj teb tus qauv, "ITS-90" Txawm tias yav tom ntej tsis yog lawm tab sis International Standards Advisory Committee (CCT) ntseeg hais tias cov S-hom thermocouples tseem siv tau los ntsuas qhov ntsuas thoob ntiaj teb. S-hom thermocouple yog qhov tsis muaj cua sov muaj peev xwm, thermal fais fab tuag me me, rhiab nyeem tsis tshua muaj siab, kev kho siab ua kom tsis muaj zog, rhiab heev rau cov pa phem, kim tshooj hlau, thiab yog li no ib zaug.
