Nug tsib tus neeg tias "PT100" txhais li cas thiab feem ntau koj yuav tau txais "qee yam ntawm qhov ntsuas kub" raws li cov lus teb tag nrho. Qhov ntawd yog qhov zoo yog tias koj tsuas yog tham - tab sis yog tias koj yog tus sau qhov kev yuav khoom spec, qhov khoob hauv cov lus teb yog raws nraim qhov teeb meem tshwm sim tom qab: lub sensor uas nyeem zoo ntawm lub rooj ntev zaum tab sis drifts thaum nws tau welded rau hauv lub thermowell, los yog ib qho uas yog technically raug tab sis wired txoj kev tsis ncaj ncees lawm rau lub transmitter nws noj.
Kab lus no hais txog kev siv tshuab ntawm PT100 qhov ntsuas kub npaum li cas, qhov sib txawv ntawm cov sensor hom koj yuav tau xaiv ntawm, thiab - vim tias txoj kev xav tsuas yog ua rau koj nyob deb - qhov xwm txheej tiag tiag uas tau txais ib qho ntawm cov ntsiab lus tsis raug ua rau muaj teeb meem ntsuas ntawm kab ntau lawm.
PT100 Qhov tseeb yog dab tsi
A PT100 yog qhov ntsuas kub tsis kam tiv thaiv (RTD) - lub platinum caij uas nws cov hluav taws xob tsis zoo hloov pauv hauv txoj kev paub, rov ua dua raws li qhov kub thiab txias. Lub "100" nyob rau hauv lub npe yog tus nqi kuj ntawm 0 degree: raws nraim 100 ohms. Thaum tshav kub kub, tiv taus nce; txias nws cia, tsis kam poob.
Platinum tsis yog tib cov hlau uas ua qhov no - npib tsib xee thiab tooj liab RTDs muaj nyob ib yam nkaus - tab sis platinum yeej tawm rau kev lag luam siv vim nws tsis oxidize yooj yim, tuav nws calibration ntau xyoo ntawm thermal cycling, thiab nws txoj kev nkhaus kuj zoo - txhais tau txaus tias nws tau raug standardized thoob ntiaj teb. Tus qauv ntawd yog IEC 60751, thiab nws yog cov ntaub ntawv txhua tus neeg tsim khoom lag luam cov ntaub ntawv muaj npe nyob ntsiag to txawm tias lawv tsis hais qhov tseeb.
Lub cev, lub ntsiab zaum nyob rau hauv ib tug hlau sheath - feem ntau yog 316 stainless, qee zaum Inconel los yog Hastelloy rau cov xov xwm phem - nrog cov hlau lead hlau khiav tawm mus rau lub transmitter los yog ib tug maub los analog input card. Lub sensor nws tus kheej tsis muaj zaub thiab tsis muaj logic; nws tsuas yog hloov tsis kam. Txhua yam tshwm sim hauv qab dej.
Physics Tom Qab Kev Nyeem Ntawv
Yog vim li cas Resistance hloov nrog kub
Raws li platinum heats li, atomic vibration nce, uas ua rau nws nyuaj rau electrons txav los ntawm lub lattice - kuj nce mus. Qhov kev sib raug zoo no tsis yog kab nyob thoob plaws txhua qhov, tab sis nws nyob ze txaus, thiab zoo - yam ntxwv txaus, uas nws tau raug ntes nyob rau hauv ib qho kev sib npaug es tsis yog lub rooj saib ib leeg: Cov Ntawv Xov Xwm -Van Dusen kab zauv.
Rau qhov kub siab tshaj 0 degree, daim ntawv yooj yim yog:
Rt=R0 [1 + At + Bt²]
R0 yog 100 ohms rau PT100, thiab A thiab B yog qhov ruaj khov los ntawm IEC 60751. Hauv qab 0℃ib lub sijhawm thib peb tau ntxiv vim qhov nkhaus khoov me ntsis txawv ntawm qhov ntawd. Koj tsis tas yuav cim qhov no - tab sis nws tsim nyog paub tias nws muaj, vim tias nws yog vim li cas "PT100" los ntawm ib lub chaw tsim khoom thiab "PT100" los ntawm lwm tus yuav pom zoo nrog ib leeg ntawm qhov kub thiab txias, tsis yog txhua tus muaj lawv tus kheej nkhaus.
Ib tus lej tsim nyog nco ntsoov: ntawm 100 degree, tus qauv PT100 nyeem kwv yees li 138.5 ohms. Yog tias koj tab tom kho qhov teeb meem nrog lub ntsuas ntsuas ntau thiab nws tsis nyob ze qhov twg ntawm qhov yuav tsum yog 100 degree, ib yam dab tsi tsis ncaj ncees lawm - yog lub caij, cov xaim, lossis koj qhov kev xav txog qhov kub thiab txias nws nyob qhov twg.
Kuj tseem muaj qhov sib cais uas koj yuav tsum paub txog ua ntej xaj: "European nkhaus" (alpha=0.00385) yog tus qauv txhua qhov chaw sab nraum North America, thaum lub qub "American nkhaus" (0.00392) tseem tshwm sim ntawm qee cov cuab yeej qub txeeg qub teg. Kev sib xyaw ob ntawm kev rov ua dua tshiab yog qhov qub ntawm kev nyeem ntawv kub uas tawm los ntawm ob peb degrees yam tsis muaj laj thawj pom tseeb.
Hloov Resistance rau hauv tus lej koj tuaj yeem nyeem
Ib lub tshuab xa hluav taws xob hla ib qho me me tam sim no los ntawm lub caij, ntsuas qhov hluav taws xob thoob plaws nws, suav cov kev tiv thaiv, thiab siv qhov nkhaus kom tawm qhov kub. Qhov ntawd yog nws. Qhov no kuj yog vim li cas PT100 yeej tsis muaj txiaj ntsig yam tsis muaj lub tshuab xa hluav taws xob lossis RTD- muaj peev xwm nkag tau tom qab nws - lub sensor tsuas yog ib nrab ntawm cov ntsuas ntsuas.
Cov kab lus nthuav dav uas ua rau muaj teeb meem hauv teb
Qhov no yog qhov uas ntau qhov kev txiav txim siab yuav mus tsis ncaj ncees lawm, thiab nws tsis tshua muaj vim tias leej twg tsis saib xyuas - nws tsuas yog tsis pom tseeb tshwj tsis yog ib tus neeg tau hais rau koj.
2-hlauyog pheej yig tshaj, tab sis qhov tsis kam ntawm cov hlau lead nws tus kheej tau ntxiv ncaj qha rau hauv kev nyeem ntawv. Tshaj li 30-meter cable khiav qhov yuam kev tsis tseem ceeb ntxiv lawm. Zoo rau kev khiav luv luv lossis kev saib xyuas tsis tseem ceeb; tsis zoo rau txhua yam uas koj xav kom tswj tau.
3-kabyog lub neej ntawd rau kev ua haujlwm feem ntau. Ib tug thib peb hlau cia lub transmitter kwv yees thiab tshem tawm cov hlau lead tiv thaiv, piv txwv li, peb conductors yog matched nyob rau hauv ntev thiab gauge. Kev sib npaug zoo ntawm tus nqi thiab qhov tseeb, uas yog vim li cas nws yog qhov koj yuav pom ntawm feem ntau ntawm cov txheej txheem transmitters muag hnub no.
4-kabtshem tawm cov hlau lead tiv thaiv kev ua yuam kev yuav luag tag nrho los ntawm kev sib cais tam sim no - nqa thiab qhov hluav taws xob - ntsuas cov xov hlau. Qhov no yog qhov koj xav tau rau calibration cov qauv siv los yog nyob qhov twg feem ntau ntawm cov℃yeej tseem ceeb - tab sis nws yog overkill, thiab tus nqi ntxiv, rau ntau qhov kev saib xyuas dav dav.
Qhov yuam kev uas kuv pom feem ntau tsis yog xaiv qhov tsis ncaj ncees lawm kab hauv kev sib cais - nws tau xaj 3-xaim sensor rau lub tshuab xa hluav taws xob uas tau teeb tsa rau 2-xaim tswv yim, lossis rov ua dua. Lub sensor thiab ntsuas yuav tsum tau pom zoo, thiab qhov nthuav dav yog ib qho yooj yim tsis nco thaum kev yuav khoom thiab kev ntsuas yog ob tus neeg sib txawv ua haujlwm tawm ntawm ob cov ntaub ntawv sib txawv.
Hlau-Qhov txhab vs. Nyias-Cov ntsiab lus zaj duab xis
Hlau- qhov txhabcov ntsiab lus - platinum hlau coiled nyob ib ncig ntawm lub ceramic lossis iav core - zoo li tuav calibration zoo heev nyob rau lub neej ntev kev pab cuam thiab dav kub viav vias. Lawv kim dua thiab me ntsis yooj yim dua mechanically.
Nyias- zaj duab xiscov ntsiab lus yog tsim los ntawm kev tso platinum mus rau hauv cov txheej txheem ceramic, zoo ib yam li tus ntsuj plig li cas lub microchip tau tsim. Lawv me me, pheej yig dua los tsim cov ntim, thiab tuav tau zoo dua rau kev co - uas yog vim li cas lawv tau siv ntau dua kev lag luam thiab OEM siv. Kev lag luam tawm -tawm yog qhov ntsuas qhov ntsuas qhov ntsuas qhov nqaim dua piv rau cov xaim hwm zoo- cov kab mob, tab sis rau feem ntau cov txheej txheem ua haujlwm uas qab nthab tsis tau ze ze.
Yog tias koj daim ntawv thov mob me me - xav tias HVAC ducting, kev saib xyuas lub tank dav dav - nyias- zaj duab xis yuav luag txhua qhov kev xaiv pheej yig, tsim nyog. Txuag xaim-mob rau siab- kub lossis ntev- kev pabcuam- lub neej daim ntawv thov uas qhov kev ruaj ntseg ntxiv tau txais rov qab nws cov nqi.
PT100 vs. Thermocouple vs. PT1000
Cov neeg yuav khoom tshiab rauntsuas kub ntsuasfeem ntau nug qhov twg ntawm peb cov no lawv yuav tsum qhia meej.
Tawm tsam athermocouple, PT100 yeej ntawm qhov raug thiab ntev - lub sij hawm ruaj khov nyob rau hauv qis - mus rau - nruab nrab (kwv yees li -200℃txog 850 degree) thiab tsis tas yuav them nyiaj txias-kub. Lub thermocouple yeej qhov kub siab tshaj platinum tuaj yeem ua tau, lossis qhov twg koj xav tau cov lus teb sai dua thiab tuaj yeem nyob nrog qis dua.
Tawm tsam aPIB 1000, lub hauv paus ntsiab lus ua haujlwm zoo ib yam - tib platinum, tib lub physics - tsuas yog 1,000 ohms ntawm 0℃es tsis txhob 100. Qhov siab dua lub hauv paus kuj ua rau cov hlau lead-wire yuam kev sib piv me me, yog li PT1000 feem ntau tuaj yeem tawm mus nrog 2-wire 1000 wiring. Qhov ntawd ua rau PT1000 ib qho kev xaiv zoo tshaj plaws hauv lub tsev automation, qhov twg cable khiav ntev tab sis koj tsis tau raws li qib siab precision.
Qhov xwm txheej tiag tiag: Thaum "Zoo txaus" Tsis yog
Khoom noj khoom haus- kev ua haujlwm ua haujlwm khiav cov kab pasteurization tau txais qhov ntsuas kub tsis sib haum rau lub lis piam - tsis muaj dab tsi txaus ntshai, tsuas yog ob peb degrees ntawm drift uas tshwm sim tsis tu ncua thiab tsis cuam tshuam nrog txhua yam pom tseeb hauv tus txheej txheem nws tus kheej. Kev saib xyuas twb tau pauv lub sensor ib zaug, xav tias nws kho qhov teeb meem, thiab txav mus rau. Nws rov qab los ib hlis tom qab.
Qhov laj thawj tiag tiag tau hloov mus rau kev xaim, tsis yog lub sensor: tus thawj 3-hlau PT100 tau hloov nrog ib chav tsev los ntawm lwm tus neeg muag khoom uas nws cov hlau ntsuas hluav taws xob sib txawv me ntsis los ntawm cov thawj khiav, uas cuam tshuam cov hlau lead -tsis kam them tus transmitter yog xam. Ntawm daim ntawv, ob lub sensors tau ntsib spec. Hauv kev xyaum, qhov tsis sib xws tsuas yog loj txaus los cuam tshuam qhov kev nyeem ntawv sab nraud ntawm qhov kev ua siab ntev uas tseem ceeb rau pasteurization tuav lub sij hawm - cov khoom noj-kev nyab xeeb, tsis yog tshuaj pleev ib ce.
Qhov kho tsis yog qhov zoo dua sensor. Nws yog standardizing txhuas hlau gauge thiab ntev nyob rau hauv tag nrho cov hloov Tshuag rau cov kab ntawd, thiab ntxiv ib tug ceev tiv thaiv check ntawm ambient kub raws li ib tug tau txais - kauj ruam tshuaj xyuas ua ntej ib tug tshiab sensor mus rau hauv kev pab. Cov lus qhia dav dav: PT100 tsuas yog qhov tseeb raws li tag nrho cov ntsuas ntsuas nyob ib puag ncig nws, thiab "tus lej qub" tsis yog ib txwm txhais tau tias " tib lub xov tooj tiag tiag."
Yuav Ua Li Cas Tiag Ua Ntej Koj xaj
Rau feem ntau cov neeg yuav khoom, qhov kev txiav txim siab los rau tsib nqe lus nug, kwv yees hauv qhov kev txiav txim ntawm qhov tseem ceeb:
- Cov txheej txheem kub npaum li cas thiab qhov kev ua siab ntev npaum li cas yuav tsum yog?Qhov no txiav txim siab qhov tseeb hauv chav kawm - Chav B (± 0.30℃ntawm 0 degree) npog feem ntau kev saib xyuas; Chav Kawm A lossis 1/3 DIN yog tsim nyog rau tus nqi rau kev tswj lub voj voog lossis cov txheej txheem tswj.
- Koj qhov xaim hluav taws xob lossis daim npav PLC xav tau dab tsi?Paub meej qhov no ua ntej kev txiav txim, tsis yog tom qab - nws yog ib qho ua rau muaj kev zam rau thaj chaw.
- Dab tsi yog cov ntaub ntawv sheath thiab sojntsuam txoj kab uas hla haum rau koj cov txheej txheem xov xwm thiab siab?Corrosive lossis siab - cov ntawv thov siab feem ntau hu rau lub thermowell thiab, ob qho tib si rau kev tiv thaiv thiab yog li lub sensor tuaj yeem hloov pauv yam tsis muaj kev kaw.
- Koj puas xav tau lub taub hau -mounted transmitter?Kev hloov mus rau 4-20mA teeb liab txoj cai ntawm lub sensor txhim kho lub suab nrov tiv thaiv ntawm kev khiav mus ntev thiab tsim nyog tus nqi ntxiv hauv cov hluav taws xob tsis zoo.
- Koj qhov calibration thiab hloov txoj kev npaj yog dab tsi?Sensors drift dhau xyoo ntawm thermal cycling. Cov txheej txheem tseem ceeb feem ntau tau kuaj xyuas txhua xyoo; qis- cov ntsiab lus saib xyuas cov ceg txheem ntseeg tuaj yeem mus ntev dua.
Installation Notes Tsim nyog Paub
Insertion qhov tob tseem ceeb tshaj li cov neeg feem coob xav tias - cov lus qhia xav tau kom ncav cuag qhov tseeb ntws los yog nruab nrab, tsis yog cuam tshuam los ntawm cov yeeb nkab phab ntsa, lossis koj xaus ntsuas qhov ciam teb txheej txheem. Thermowells tsim nyog tus nqi ntxiv nyob txhua qhov chaw siab, corrosion, lossis xav tau kub - hloov pauv yog qhov tseem ceeb. Thiab yog tias koj tab tom daws teeb meem kev nyeem ntawv uas zoo li tawm, xyuas qhov kev tiv thaiv ntawm qhov kev paub txog qhov kub thiab txias (cov dej khov yog ib qho pheej yig, txhim khu kev qha 0℃siv) ua ntej xav tias lub transmitter lossis cov txheej txheem nws tus kheej yog qhov teeb meem.
Kab hauv qab
Lub physics tom qab PT100 yog qhov yooj yim thiab tsis tau hloov pauv hauv kaum xyoo - platinum qhov kev tiv thaiv nce siab nrog qhov kub thiab txias, thiab qhov kev sib raug zoo yog tus qauv yog li cov cuab yeej los ntawm cov tuam txhab sib txawv pom zoo ib leeg. Qhov twg buyers yeej mus tsis ncaj ncees lawm tsis yog lub sensor xaiv nws tus kheej; nws yog cov ntsiab lus nyob ib ncig ntawm nws - thaiv kev teeb tsa, cov hlau lead zoo sib xws, cov ntaub qhwv rau cov txheej txheem tiag tiag. Tau txais cov cai ntawm cov theem spec thiab qhov sensor yog qhov yooj yim.
Yog tias koj tab tom nrhiav PT100 sensors rau cov kab tshwj xeeb lossis cov khoom siv, xa koj tus neeg xa khoom mus rau qhov kub thiab txias, xav tau cov chav kawm raug, hom xov, thiab qhov chaw teeb tsa rau pem hauv ntej - es tsis yog ib feem ntawm tus lej - feem ntau yog dab tsi cais lub sensor uas ua haujlwm ntawm ib qho uas tau sib pauv ob zaug ua ntej ib tus neeg pom qhov teeb meem tiag tiag.
Cov lus nug nquag
Puas yog PT100 tib yam li RTD?
Tsis yog - PT100 yog ib hom RTD tshwj xeeb, ua los ntawm platinum nrog 100 ohms tsis kam ntawm 0℃. RTD yog qeb dav dav, uas kuj suav nrog PT500, PT1000, thiab npib tsib xee- lossis tooj liab- raws li sensors.
Qhov tseeb npaum li cas yog PT100 sensor, tiag tiag?
Chav B yog qhov tseeb txog ± 0.30℃ntawm 0 degree. Chav Kawm A nruj kom roughly ± 0.15 degree. Siab -precision 1/10 DIN sensors ncav cuag ± 0.03 degree, uas feem ntau yog ib qho chaw kuaj lossis ntsuas ntsuas -tus qauv spec es tsis yog qee yam kev saib xyuas kev xav tau.
PT100 puas tuaj yeem ua haujlwm sub-zero kub?
Yog lawm, cov qauv ntsuas tau ntsuas mus txog li -200 degree, uas suav nrog feem ntau cov ntawv thov cryogenic thiab txias-chain yam tsis xav tau dab tsi tshwj xeeb.
Vim li cas qee qhov PT100 sensors muaj peb lossis plaub xov hlau tsis yog ob?
Cov xov hlau txuas ntxiv tso cai rau lub ntsuas hluav taws xob tshem tawm qhov kev tawm tsam ntawm cov hlau lead nws tus kheej, uas yuav txwv tsis pub suav tias yog ib feem ntawm cov teeb liab kub - qhov yuam kev uas loj hlob nrog cable ntev.
Cov ntaub ntawv
- International Electrotechnical Commission.IEC 60751 - Muaj platinum tiv thaiv ntsuas kub thiab platinum kub sensors.
- National Institute of Standards and Technology (NIST).ITS-90 Temperature Scale thiab Platinum Resistance Thermometry Reference Data.
- Omega Engineering.RTD (Resistance Temperature Detector) Phau Ntawv Qhia.
- Fluke Corporation.Calibration: Philosophy in Practice - Resistance Thermometry.
