Ntev npaum li cas 4-20mA Tshaj Tawm Tshaj Tawm?

Ntev npaum li cas 4-20mA Teeb Pom Kev Tshaj Tawm?

Qhov no tsis yooj yim heev los teb cov lus nug, yog tias lwm yam cuam tshuam tag nrho lwm yam tsis quav ntsej, peb tuaj yeem kwv yees

rau ib txwm mob, nws tuaj yeem mus txog 200-500m. Cia peb paub qee cov ntaub ntawv yooj yim txog 4-20mA.

1. Lub teeb liab 4-20mA yog dab tsi?

Lub teeb liab 4-20mA yog tus qauv raws tu qauv siv hauv ntau lub lag luam. Nws yog ib txoj hauv kev xa cov ntaub ntawv analog teeb liab hauv ob-xaim tam sim no voj, muab txoj hauv kev txhim khu kev qha los sib txuas lus ntawm cov khoom siv. Qhov tseem ceeb ntawm 4-20mA feem ntau sawv cev 0 txog 100% ntawm kev ntsuas ntau.

2. Cov txiaj ntsig ntawm 4-20mA Cov Lus Qhia

Vim li cas kev lag luam nyiam siv 4-20mA cov teeb liab? Rau ib qho, lawv tsis tshua muaj suab nrov piv rau cov teeb liab voltage. Qhov no ua rau kev sib kis tau ntev dua yam tsis muaj kev cuam tshuam cov teeb liab kev ncaj ncees. Tsis tas li ntawd, "nyob xoom" ntawm 4mA tso cai rau kev kuaj xyuas qhov txhaum.

3. Lub teeb liab 4-20mA kis tau li cas?

Lub teeb liab 4-20mA yog kis los ntawm ob-xaim tam sim no lub voj uas ib lub xaim yog cov khoom siv hluav taws xob thiab lwm qhov yog txoj hauv kev rov qab mus rau qhov chaw. Qhov sib txawv tam sim no nyob rau hauv lub voj yog cov ntaub ntawv teeb liab.

4. Tab sis muaj qee yam uas koj yuav tsum xav txog:

Interfered Element:

①Excitation voltage;

②Yam tsawg kawg nkaus ua haujlwm Voltage tso cai los ntawm Transmitter;

③Qhov loj ntawm qhov voltage-taking resistor siv los ntawm lub rooj tsavxwm ntaus ntawv los sau tam sim no;

④Qhov loj ntawm cov hlau tsis kam.

Nws tuaj yeem yooj yim xam qhov theoretical kis nrug deb ntawm 4-20mA tam sim no teeb liab.

Los ntawm cov plaub muaj feem cuam tshuam. Ntawm lawv, Uo yog cov khoom siv hluav taws xob ntawm lub transmitter,

thiab nws yuav tsum tau xyuas kom meej tias Uo ≥ Umin ntawm tag nrho cov load (tam sim no I = 20mA). Namely: Siv-I.(RL+2r)≥ Umin.

Nws feem ntau yuav tsum ntsuas ntau yam tsis muaj hluav taws xob lub cev xws li kub, siab,

tus nqi, lub kaum ntse ntse thiab lwm yam hauv kev lag luam. Lawv txhua tus yuav tsum tau hloov mus rau hauv ib qho analoguehluav taws xob

teeb liab uas hloov mus rau ib qho kev tswj los yog tso saib ntaus ntawv ob peb puas meters deb. Cov cuab yeej no converts

lub cev kom muaj nuj nqis rau hauv lub teeb liab hluav taws xob hu ua transmitter. Xa cov analogue kom muaj nuj nqis los ntawm

4-20 mA tam sim no yog txoj kev siv ntau tshaj plaws hauv kev lag luam. Ib qho laj thawj rau kev siv lub teeb liab tam sim no

yog tias nws tsis yooj yim rau kev cuam tshuam nrog thiab infinite internal resistance ntawm qhov tam sim no.

Kev ua haujlwm ntawm cov hlau hauv series hauv lub voj tsis cuam tshuam qhov raug, thiab nws tuaj yeem xa mus ntau pua

ntawm meters ntawm qhov sib tw twisted.

4-20mAxa mus rau min tam sim no li 4mA, thiab max tam sim no yog 20mA. Raws li qhov xav tau tawg-pov thawj,

Qhov kev txwv yog 20mA. Lub txim hluav taws xob ntau dhau tuaj yeem ua rau hluav taws kub hnyiab tau thiab tawg, yog li 20mA tam sim no haum tshaj plaws.

Tshawb xyuas cov xov hlau tawg, thiab qhov tsawg kawg nkaus tus nqi yog 4mA es tsis yog 0mA. Thaum lub tshuab xa hluav taws xob tawg vim muaj kev ua txhaum,

lub voj tam sim no poob mus rau 0. Peb feem ntau siv 2mA raws li tus nqi ceeb toom tsis sib xws. Lwm qhov laj thawj yog tias 4-20mA siv a

ob-xaim system. Ntawd yog, ob lub xov hlau yog lub teeb liab thiab lub zog xaim ib txhij, thiab 4mA yog siv los muab cov haujlwm zoo li qub ntawm lub voj voog mus rau lub sensor.

Ntev npaum li cas 4-20mA Teeb Pom Kev Tshaj Tawm?

Interfered Element:
① Muaj feem xyuam rau qhov excitation voltage;

②Txog rau qhov tsawg kawg nkaus kev khiav hauj lwm voltage tso cai los ntawm lub transmitter;

③ Muaj feem cuam tshuam rau qhov loj ntawm qhov ntsuas hluav taws xob siv hluav taws xob siv los ntawm lub rooj tsavxwm los sau cov khoom tam sim no;

④ Muaj feem xyuam rau qhov loj ntawm cov hlau tsis kam.

Nws tuaj yeem yooj yim xam qhov theoretical kis nrug deb ntawm 4-20mA tam sim no teeb liab.

Los ntawm cov plaub muaj feem cuam tshuam. Ntawm lawv, Uo yog cov khoom siv hluav taws xob ntawm lub transmitter,

thiab nws yuav tsum tau xyuas kom meej tias Uo≥Umin ntawm tag nrho cov load (tam sim no I = 20mA). Namely: Siv-I.(RL+2r)≥Umin.

Raws li cov qauv no, cov hlau loj loj tuaj yeem suav tau thaum lub tshuab xa hluav taws xob nyob ntawm qhov kev ua haujlwm qis.

Kev xav: paub: Ue = 24V, I = 20mA, RL = 250Ω, Umin = 12V.Nrhiav tus nqi siab tshaj ntawm r li 175Ω:

Thiab tom qab ntawd, raws li kev suav cov qauv ntawm cov hlau tsis kam:

Ntawm lawv:
ρ——Resistivity(Bronze Resistivity = 0.017, Txhuas resistivity = 0.029)
L - Qhov ntev ntawm cable (Unit: M)
S-Line ntawm ntu ntu (Unit: Square millimeter)
Faj seeb: Tus nqi kuj yog proportional rau qhov ntev thiab inversely proportional rau qhov cross-sectional cheeb tsam.

Qhov ntev ntawm cov hlau, qhov ntau dua qhov kev tiv thaiv; lub thicker cov hlau, qhov qis kuj.

Siv tooj liab ua piv txwv, ρ = 0.017 Ω·mm2 / m, uas yog: qhov tsis kam ntawm tooj liab

nrog rau qhov chaw hla ntawm 1mm2 thiab qhov ntev ntawm 1m yog 0.017Ω. Ces cov hlau ntev ntawm

175Ω sib raug rau 1mm2 yog 175/0.017 = 10294 (m). Hauv kev xav, 4-20mA teeb liab kis tau tus mob

tuaj yeem ncav cuag kaum tawm txhiab meters (nyob ntawm seb yam xws li kev sib txawv excitation

voltages thiab qis tshaj ua hauj lwm voltage ntawm lub transmitter).

HENGKO muaj ntau tshaj 10 xyoo ntawm OEM / ODM kev tsim kho thiab kev tshaj lij

kev sib koom tes tsim / pab tsim muaj peev xwm. Peb muab 4-20mA thiab RS485 tso zis

gas sensor/alarm/module/cov ntsiab lus. 4-20mA thiab RS485 tso zis kub thiab av noo

sensor / transmitter / sojntsuam kuj muaj.HENGKO tshwj xeeb tsim rau cov neeg siv khoom

ua tau raws li qhov xav tau kev ntsuas ntsuas ntawm cov txheej txheem kev lag luam thiab kev tswj ib puag ncig.

Vim li cas 4 mus rau 20ma yog siv rau Kev Tshaj Tawm hauv Kev Ntsuas?

Koj tuaj yeem tshawb xyuas raws li hauv qab video kom paub meej.

Xaus

Lub teeb liab 4-20mA yog kev lag luam-tus qauv rau ib qho laj thawj. Nws muaj peev xwm kis tau mus rau qhov ntev yam tsis tau poob qhov tseeb yog qhov txiaj ntsig tseem ceeb. Txawm hais tias tsis muaj lus teb meej rau "yuav deb npaum li cas" vim nws feem ntau nyob ntawm cov yam ntxwv xws li hlau tsis kam, teeb liab suab nrov, lub zog hluav taws xob, thiab kev thauj khoom tsis kam, nrog rau qhov kev ntsuas zoo, nws tuaj yeem ntseeg tau tias muaj ntau qhov kev ncua deb. Los ntawm nws cov tswv yim siv hauv kev lag luam thiab kev siv tshuab sensor, peb pom tus nqi thiab qhov tseem ceeb ntawm 4-20mA cov cim hauv peb lub ntiaj teb kev sib txuas.

FAQs

1. Dab tsi yog qhov tseem ceeb ntawm "nyob zero" ntawm 4mA hauv 4-20mA teeb liab?

Qhov "nyob xoom" ntawm 4mA tso cai rau kev kuaj xyuas qhov txhaum. Yog tias lub teeb liab poob qis dua 4mA, nws qhia tau tias muaj kev ua txhaum, xws li kev tawg hauv lub voj lossis lub cuab yeej tsis ua haujlwm.

2. Vim li cas lub teeb liab 4-20mA tsis tshua muaj suab nrov?

Cov teeb liab tam sim no tsis tshua muaj cuam tshuam los ntawm kev hloov pauv thiab hluav taws xob nrov. Qhov no yog vim li cas lawv thiaj nyiam rau kev sib kis mus ntev thiab nyob rau hauv qhov chaw muaj suab nrov.

3. Lub luag hauj lwm dab tsi yog qhov ua haujlwm ntawm kev ua haujlwm ntawm kev sib kis ntawm 4-20mA teeb liab?

Lub load kuj yuav tsum phim lub hwj chim mov. Yog hais tias lub load kuj siab dhau lawm, lub hwj huam mov yuav tsis muaj peev xwm tsav lub voj tam sim no, txwv kev sib kis deb.

4. Lub teeb liab 4-20mA puas tuaj yeem xa mus rau wirelessly?

Yog lawm, nrog kev siv cov transmitters thiab receivers tshwj xeeb tsim los rau lub hom phiaj no, 4-20mA cov teeb liab tuaj yeem xa mus rau wirelessly.

5. Nws puas tuaj yeem txuas ntxiv qhov kev ncua deb ntawm 4-20mA teeb liab?

Yog lawm, los ntawm kev siv cov xaim kom raug, txo cov suab nrov, ua kom muaj lub zog txaus, thiab sib npaug ntawm kev sib tw, kev sib kis tau ntev.

Yog tias koj txaus siab los ntawm lub peev xwm ntawm 4-20mA cov cim thiab xav siv lossis ua kom zoo dua cov tshuab hauv koj qhov kev lag luam,

tsis txhob yig mus ua cov kauj ruam tom ntej. Yog xav paub ntxiv, kev txhawb nqa, lossis kev sab laj, hu rau cov kws tshaj lij.

Hu rau HENGKO tam sim no ntawmka@hengko.comthiab cia peb ua tiav qhov kev sib kis tau zoo ua ke.