Yog tias koj tau siv txhua lub sijhawm nyob ib puag ncig kev ntsuas kev lag luam, koj yuav luag tau hnov cov neeg sib pauv "transducer" thiab "transmitter" rov qab los. Cov kws tshaj lij tshiab sib xyaw ua ke, pawg neeg yuav khoom nug txog ib qho thaum lawv txhais li cas, thiab txawm tias qee cov khoom lag luam catalogs siv cov ntsiab lus sib hloov. Qhov kev tsis meej pem no ua rau muaj teeb meem tiag tiag ntawm qhov chaw - Kuv tau pom qhov project qeeb thiab xa rov qab cov khoom xa tuaj tsuas yog vim tsis muaj leej twg nres los qhia meej meej tias txhua lub cuab yeej ua li cas, thiab lawv ua haujlwm ua ke li cas.
Qhov tseeb, lawv tsis yog tib yam. Transducer thiab transmitter ua haujlwm ua ib khub, thiabtxhua lub siab transmittertso siab rau ob qho tib si los siv lub cev lub zog nyeem ntawv thiab xa nws hla cov nroj tsuag mus rau kev tswj hwm.
Phau ntawv qhia no rhuav tshem cov ntsiab lus sib txawv ntawm ob, taug kev ib kauj ruam los ntawm kev ua haujlwm ntawm lub tshuab hluav taws xob zoo li cas, piav qhia peb hom kev ntsuas siab tshaj plaws, thiab npog cov qauv tso tawm cov cim uas koj yuav pom hauv txhua txoj kev cog. Thaum kawg, koj tuaj yeem qhia ob qhov sib nrug, nkag siab tias muaj dab tsi tshwm sim hauv lub tsev xa khoom, thiab txiav txim siab qhov loj dua rau koj tus kheej daim ntawv thov.
Transmitter vs. Transducer: Dab tsi yog qhov txawv?
Qhov yooj yim tshaj plaws kom lawv ncaj yog qhov no: lub transducer hnov lub siab, thiab lub transmitter xa cov teeb liab. Lawv yog ob txoj haujlwm sib cais uas feem ntau ntim ua ke hauv ib lub cuab yeej - uas yog vim li cas coob tus neeg sib xyaw cov ntsiab lus.
Qhov transducer ua li cas
Lub transducer yog ib qho khoom siv uas hloov ib hom ntawm lub zog mus rau lwm qhov. Hauv kev ntsuas siab, nws yuav siv lub zog siv lub cev los ntawm cov kua lossis roj siab thiab hloov mus rau qhov me me, tsis muaj zog hluav taws xob teeb liab.
Cov zis hluav taws xob nyoos ntawd tsawg heev - feem ntau yog millivolts - thiab nws tsis yog tus qauv. Nws txawv ntawm ib qho kev tsim sensor mus rau lwm qhov, thiab nws tsis muaj zog heev rau kev mus ncig ntau dua li qhov luv luv yam tsis tau khaws lub suab nrov thiab poob qhov tseeb. Ntawm nws tus kheej, lub teeb liab transducer nyoos tsis muaj txiaj ntsig rau kev xa mus rau PLC lossis DCS ntawm sab nraud ntawm qhov chaw.
Transducers tuaj nyob rau hauv ntau yam sensing technologies: strain gauge, capacitive, piezoelectric, potentiometric thiab ntau dua. Qhov twg yog siv nyob ntawm qhov siab ntau, hom nruab nrab, qhov kub thiab txias thiab qhov tseeb ntawm daim ntawv thov.
Tus transmitter ua li cas
Lub transmitter siv lub zog tsis muaj zog, tsis yog - qauv hluav taws xob teeb liab los ntawm lub transducer thiab tej yam kev mob, amplifies thiab converts nws mus rau hauv ib tug standardized kev lag luam tso zis teeb liab uas tuaj yeem mus ntev kev ntseeg tau.
Lub transmitter txoj hauj lwm yog tig ib tug me me sib txawv teeb liab mus rau ib tug zoo sib xws, universally lees paub ntau yam - feem ntau 4-20 mA rau tam sim no loops, los yog 1-5 V rau voltage outputs - qhov twg hauv qab ntawm qhov ntau yam sib npaug 0% ntawm qhov ntsuas siab, thiab sab saum toj sib npaug 100%. Cov teeb liab txheem no tuaj yeem khiav ntau pua meters los ntawm cov kab cog qoob loo yam tsis tau poob qhov tseeb, thiab txhua qhov kev tswj hwm hauv ntiaj teb paub yuav txhais li cas.
Vim li cas cov ntsiab lus sib xyaw ua ke ntau zaus
Yuav luag tag nrho cov niaj hnub siab transmitters muag niaj hnub no pob ob lub transducer sensing caij thiab lub transmitter Circuit Court nyob rau hauv ib lub tsev. Rau feem ntau cov twj paj nruag, koj tsis yuav lawv cais - koj yuav ib lub rooj sib txoos ua tiav.
Nyob rau tib lub sijhawm, kev lag luam pib hu tag nrho lub tsev los ntawm ob lub npe. Qee tus neeg muag khoom hu nws lub siab transducer, lwm tus hu nws lub siab transmitter, thiab rau feem ntau tawm -the- txee teb, ob lub npe xa mus rau tib yam khoom tiav. Qhov sib txawv tsuas yog qhov tseem ceeb thaum koj tab tom kho cov khoom siv sab hauv, ntsuas cov khoom siv raw rau kev tsim, lossis sib piv cov khoom sib xyaw- theem.
Yuav ua li cas lub siab Transmitter ua haujlwm tiag tiag (Ib kauj ruam los ntawm kauj ruam)
Nyob rau hauv txhua qhov kev lag luam siab transmitter, muaj peb theem tseem ceeb: kev sib cais diaphragm, lub suab transducer, thiab lub teeb liab transmitter Circuit Court. Nov yog qhov tshwm sim ntawm txhua theem thaum koj siv cov txheej txheem siab.
Theem 1: Kev ntsuas diaphragm ua rau thawj zaug sib cuag
Cov txheej txheem kua los yog roj yeej tsis kov cov khoom muag muag ncaj qha. Nws thawj zaug nias tawm tsam nyias, robust ntsuas diaphragm welded los yog clamped rau cov txheej txheem kev twb kev txuas lub ntsej muag ntawm lub transmitter.
Cov diaphragm no yog ua los ntawm stainless hlau, Hastelloy, los yog lwm yam corrosion{0}}cov ntaub ntawv resistant matched rau cov txheej txheem nruab nrab. Nws flexes me ntsis nyob rau hauv siab, thiab hloov uas quab yuam los ntawm ib tug sau kua (feem ntau silicone roj los yog lwm yam inert kua) mus rau qhov tseeb sensor keeb nyob rau sab nraud.
Qhov kev sib cais no ua haujlwm rau ob lub hom phiaj tseem ceeb:
- Nws tiv thaiv cov ntaub ntawv tsis txaus ntseeg los ntawm corrosive, abrasive lossis qias neeg txheej txheem xov xwm
- Nws tso cai rau lub sensor kom ntsuas thiab kaw ntawm lub hoobkas, yog li nws nyob twj ywm raug rau xyoo nyob rau hauv hnyav teb.
Theem 2: Lub transducer converts quab yuam rau hluav taws xob teeb liab
Tom qab cov kua filling zaum ntawm transducer - qhov tseeb siab sensor. Peb technologies feem ntau yog siv rau hauv cov txheej txheem kev lag luam:
Kev ntsuas ntsuas sensorsyog cov siv ntau tshaj plaws. Ib tug qauv ntawm cov strain me me-sensitive resistors yog khi rau ib tug nruj diaphragm. Thaum lub siab deflects lub diaphragm, cov resistors stretch los yog compress, hloov lawv cov hluav taws xob tsis kam. Qhov kev hloov pauv no me me thiab ntsuas los ntawm Wheatstone choj Circuit Court, ua rau millivolt- theem tso zis proportional rau siab.
Capacitive sensorssiv ob daim hlau sib luag, ib qho ruaj khov thiab ib qho txuas rau lub diaphragm hloov tau. Raws li lub siab txav lub diaphragm, qhov sib txawv ntawm cov phaj hloov, uas hloov hluav taws xob capacitance. Qhov kev tsim qauv no ruaj khov heev ntawm qhov siab tsis tshua muaj siab thiab ua tau zoo nyob rau hauv qhov dav kub viav vias.
Piezoelectric sensorsua kom muaj qhov hluav taws xob me me ncaj qha thaum cov khoom siv crystalline muab tso rau hauv cov neeg kho tshuab kev ntxhov siab. Lawv ua tau zoo ntawm kev ntsuas qhov nrawm nrawm thiab hloov siab hloov pauv, tab sis tsis tshua muaj rau kev ruaj khov- lub xeev cov txheej txheem ntsuas siab.
Nyob rau hauv txhua rooj plaub, qhov kawg tshwm sim yog tib yam: ib tug me me hluav taws xob teeb liab uas hloov raws li lub siab hloov. Ntawm nws tus kheej, cov teeb liab no tsis muaj zog thiab tsis yooj yim heev kom xa mus rau ib tsob nroj.
Kauj Ruam 3: Lub transmitter Circuit Court tsim cov qauv tso zis
Cov teeb liab transducer raw khoom nkag mus rau hauv lub transmitter's electronic circuit board. Lub rooj tsavxwm no ua peb yam tseem ceeb:
1.Signal conditioning: Nws lim tawm cov suab nrov hluav taws xob, them nyiaj rau qhov kub thiab txias, thiab linearizes cov zis kom lub teeb liab sib npaug siab sib npaug thoob plaws ntau yam.
2. Amplification: Nws txhawb nqa cov teeb liab me me millivolt mus txog qhov muaj zog, siv tau.
3.Standardization: Nws hloov cov teeb liab mus rau qhov kev lees paub thoob ntiaj teb tso zis ntau yam - yuav luag ib txwm 4-20 mA rau ob-wire industrial installations, lossis 1-5 V rau kev siv lub txee luv luv.
Qhov kawg txheej txheem teeb liab khiav tawm los ntawm lub transmitter terminals mus rau lub kaw lus tswj, qhov twg PLC los yog DCS nyeem cov tam sim no los yog voltage tus nqi thiab maps nws rov qab mus rau qhov tseeb siab nyeem ntawv.
3 Hom Kev Ntsuas Siab
Siab transmitters tsis yog txhua qhov ntsuas siab ib yam nkaus. Qhov lawv siv raws li lawv "zero point" hloov li cas kev nyeem ntawv yuav tsum tau txhais. Muaj peb hom tseem ceeb, thiab xaiv qhov tsis ncaj ncees lawm yog qhov yuam kev loj heev.
Ntsuas siab
Kev ntsuas siab yog hom siv ntau tshaj plaws hauv cov nroj tsuag txheej txheem. Nws ntsuas qhov siab txheeb ze rau lub siab tam sim no atmospheric.
Thaum lub ntsuas ntsuas siab nyeem ntawv 0, qhov ntawd txhais tau hais tias lub siab sab hauv sib npaug ntawm huab cua nyob sab nraud. Kev nyeem ntawv feem ntau sau npe nrog ib (g) cov lus, xws li psi(g) lossis bar(g).
Gauge siab yog siv rau feem ntau lub tank siab, kab siab thiab twj tso kua mis ntsuas. Yog tias koj tsis muaj qhov laj thawj tshwj xeeb los ntsuas qhov siab lossis qhov sib txawv, koj yuav luag xav tau ntsuas qhov ntsuas siab.
Siab siab
Kev ntsuas siab yog ntsuas txheeb ze rau lub tshuab nqus tsev zoo - 0 psi(a)=tag nrho lub tshuab nqus tsev. Nws suav nrog atmospheric siab ua ib feem ntawm kev nyeem ntawv.
Nyob rau hauv lub hiav txwv theem, ib txwm atmospheric siab yog roughly 14.7 psi(a). Qhov ntawd txhais tau hais tias lub tank qhib rau huab cua yuav nyeem 14.7 psi(a) ntawm lub tshuab hluav taws xob siab, thiab 0 psi (g) ntawm lub ntsuas hluav taws xob siab.
Lub siab tsis muaj zog yog siv rau cov txheej txheem nqus tsev, kaw cov pa roj, ntsuas vapor siab thiab txhua daim ntawv thov uas koj xav tau kev nyeem ntawv ywj pheej ntawm kev hloov pauv hauv huab cua hauv zos.
Differential siab
Differential siab (DP) transmitters ntsuas qhov sib txawv ntawm qhov siab ntawm ob qhov sib txawv input ports. Lawv tsis qhia koj tias qhov siab ntawm ob lub ntsiab lus - tsuas yog ntau npaum li cas ib sab siab dua lwm qhov.
Qhov no yog ib hom kev ntsuas ntau yam. Differential siab transmitters yog siv rau:
- Flow ntsuas hla cov paib, Venturi raj thiab ntws nozzles
- Kev ntsuas qib hauv cov tso tsheb hlau luam siab los ntawm kev sib piv lub taub hau siab rau roj pam siab siab
- Filter thiab strainer clog nrhiav tau los ntawm kev ntsuas kev poob siab
- Pump sib txawv siab saib xyuas
Lub sensor sab hauv ua haujlwm tib yam li txoj hauv kev, tab sis nws raug rau lub siab ntawm ob sab ntawm lub suab diaphragm es tsis yog ib qho xwb.
Standard Output Signals: 4–20mA vs . 1–5V
Koj yuav pom ob cov qauv tsim tawm siv thoob plaws yuav luag txhua qhov kev lag luam siab transmitters. Txhua tus muaj nws tus kheej cov ntaub ntawv siv zoo tshaj plaws.
4-20 mA tam sim no voj voog (feem ntau)
Lub teeb liab 4-20 mA yog lub zog ua haujlwm ntawm kev tswj cov txheej txheem kev lag luam . 4 mA sib raug rau 0% ntawm qhov siab ntau, thiab 20 mA sib haum rau 100%.
Qhov txiaj ntsig loj tshaj plaws ntawm lub teeb liab tam sim no yog tias nws tsis degrade dhau ntawm cov xaim ntev ntev, thiab nws muaj zog heev rau cov suab nrov ntawm cov motors, VFDs thiab lwm yam khoom siv cog. Nws kuj tseem txhawb nqa ob- xaim ua haujlwm, qhov twg tib khub ntawm cov xov hlau muab ob lub zog rau lub tshuab xa tawm thiab nqa cov teeb liab ntsuas.
Lub 4 mA "nyob xoom" yog txhob txwm: yog tias lub teeb liab poob rau 0 mA, lub kaw lus tswj tam sim ntawd lees paub tias nws yog lub xaim tawg lossis xaim tsis tau, tsis yog xoom siab nyeem ntawv. Qhov no yog qhov tseem ceeb ntawm kev nyab xeeb thiab kev kuaj mob.
1-5V voltage tso zis
Voltage outputs tsis tshua muaj nyob rau hauv kev teeb tsa tab sis dav siv nyob rau hauv cov khoom tswj, lub rooj zaum thiab cov ntawv thov luv dua . 1 V=0% range, 5 V=100% range.
Cov teeb liab hluav taws xob yog yooj yim dua thiab pheej yig dua rau kev khiav luv luv, tab sis lawv poob qhov tseeb ntawm qhov ntev vim yog cov hlau tsis kam, thiab lawv tuaj yeem cuam tshuam hluav taws xob ntau yooj yim dua. Lawv kuj xav tau kev sib txuas hluav taws xob. Rau txhua yam sab nraud ntawm ib puag ncig tswj txee, 4-20 mA yuav luag txhua qhov kev xaiv zoo dua.
Cov tswv yim xaiv ceev & cov kev xav tsis zoo
Tom qab ua haujlwm nrog cov cuab yeej no hla cov txheej txheem cov nroj tsuag, muaj qee qhov yuam kev uas kuv pom rov qab ntau dua li lwm tus.
1.Tsis txhob yuav lub siab los ntawm kev sib tsoo. Yog tias koj xaj ib qho kev xa tawm tiag tiag rau daim ntawv thov kev ntsuas siab, tag nrho koj cov kev nyeem yuav raug tawm los ntawm kwv yees li 14.7 psi. Ib txwm muab ob npaug rau- txheeb xyuas hom kev siv ua ntej tso qhov kev txiav txim.
2.4-20 mA tsis tau siv lawm. Txawm tias tag nrho cov digital fieldbus raws tu qauv muaj nyob rau niaj hnub no, dawb 4-20 mA tseem yog qhov kev txhawb nqa thoob ntiaj teb, yooj yim tshaj plaws los daws teeb meem thiab txhim khu kev qha tshaj plaws rau kev ntsuas siab.
3.Qhov tseeb yog nyob ntawm ntau tshaj qhov sensor. Lub siab -precision transducer tseem yuav muab cov ntawv nyeem tsis zoo yog tias nws tau teeb tsa tsis raug, raug kub hnyiab sab nraum nws qhov kev ntsuam xyuas, lossis sib phim rau cov khoom siv diaphragm tsis raug rau cov txheej txheem nruab nrab.
Yog tias koj sizing siab transmitters rau koj cov txheej txheem thiab tsis paub tseeb tias lub siab hom twg, cov teeb liab tso zis lossis cov khoom siv diaphragm haum rau koj daim ntawv thov, nws ib txwm tsim nyog lees paub nrog tus kws tshaj lij ntsuas ntsuas ua ntej. Tau txais cov lus qhia tshwj xeeb nyob rau pem hauv ntej kawg zam lub lim tiam ntawm kev ncua sij hawm ua ntej thiab rov qab los tom qab.
Cov lus nug nquag
Puas yog lub siab transducer zoo ib yam li lub transmitter?
Tsis raws nraim. Ib tug transducer converts siab mus rau ib tug raw hluav taws xob teeb liab. Lub transmitter siv cov teeb liab nyoos thiab hloov nws mus rau hauv cov qauv, ntev - cov zis ntau. Feem ntau cov khoom siv hluav taws xob uas muag niaj hnub no suav nrog ob qho tib si hauv ib lub tsev, yog li cov ntsiab lus feem ntau siv sib hloov.
Vim li cas 4-20mA siv 0-20mA?
Lub 4 mA nyob xoom ua haujlwm rau ob lub hom phiaj: nws ua rau lub tshuab xa hluav taws xob ntawm ob - xov hlau voj, thiab nws cia lub kaw lus tswj qhia qhov sib txawv ntawm qhov tseeb xoom siab nyeem ntawv thiab cov xaim tawg lossis xaim tsis tau. Yog tias lub teeb liab poob mus rau 0 mA, nws tam sim ntawd lees paub tias yog qhov txhaum.
Peb hom kev ntsuas siab yog dab tsi?
Peb lub hom phiaj tseem ceeb yog ntsuas qhov siab (xws li huab cua), lub siab tsis txaus (xa mus rau lub tshuab nqus tsev) thiab qhov sib txawv siab ( ntsuas qhov sib txawv ntawm ob lub ntsiab lus).
Lub transducer puas tuaj yeem ua haujlwm yam tsis muaj transmitter?
Lub transducer nyoos yuav tsim hluav taws xob teeb liab, tab sis nws yuav tsis muaj zog heev, tsis yog - tus qauv thiab tsis haum rau kev sib kis mus ntev. Rau kev tswj cov txheej txheem dav dav siv, lub tshuab xa hluav taws xob yuav tsum tau ua kom zoo thiab ua qauv rau lub teeb liab.
Kev xav zaum kawg
Lub tshuab xa hluav taws xob yog ib qho cuab yeej siv ntau tshaj plaws hauv cov txheej txheem cog, tab sis nws yooj yim los kho lawv zoo li lub thawv dub. Kev nkag siab txog qhov sib txawv ntawm lub transducer thiab lub transmitter, yuav ua li cas lub luag hauj lwm ntawm lub sensor ua hauj lwm, thiab qhov txawv siab thiab teeb liab hom txhais tau li cas yuav pab tau koj qhia lawv kom raug, teeb meem lawv sai dua, thiab zam cov feem ntau sizing yuam kev.
Thaum kawg ntawm lub hnub, qhov zoo tshaj plaws siab transmitter tsis yog ib qho nrog cov fanciest specs - nws yog ib tug kom haum haum rau koj cov txheej txheem nruab nrab, siab ntau yam, kub thiab installation ib puag ncig.
Yog tias koj xav tau kev pab xaiv lub tshuab xa hluav taws xob zoo rau koj daim ntawv thov, lossis koj muaj lus nug txog cov khoom tso tawm, cov ntaub ntawv diaphragm lossis hom siab, peb pab neeg ua haujlwm tuaj yeem tshuaj xyuas koj cov txheej txheem tsis ua haujlwm thiab pom zoo kom muaj kev teeb tsa kom raug.
Cov ntaub ntawv
- International Society of Automation (ISA). (2022).Kev ntsuas siab: Cov ntsiab lus, installation thiab calibration. Research Triangle Park, NC: ISA.
- Rosemount Inc. (2024).Pressure Transmitter Fundamentals: Technology and Application Guide. Emerson Automation Solutions.
- WIKA Alexander Wiegand SE & Co. KG. (2023).Siab Transducers vs. Transmitters: Kev piav qhia. WIKA Industrial Instrumentation.
- National Institute of Standards and Technology (NIST). (2021).Calibration ntawm cov cuab yeej ntsuas siab. NIST Phau Ntawv 150.
- ABB Kev Ntsuas & Kev Ntsuas. (2024).Industrial Pressure Transmitters: Technology Xaiv Phau Ntawv Qhia.
