Kev faib tawm thiab cov lus qhia ua haujlwm ntawm digital multimeters
Kev faib tawm ntawm digital multimeters
Digital multimeters raug cais raws li kev hloov pauv ntau yam thiab tuaj yeem muab faib ua peb hom: phau ntawv ntau yam (MAN RANGZ), tsis siv neeg ntau yam (AUTO RANGZ), thiab tsis siv neeg / phau ntawv ntau yam (AUTO / MAN RANGZ).
Raws li kev ua haujlwm sib txawv, kev siv thiab tus nqi, digital multimeters tuaj yeem muab faib ua 9 pawg:
Tsawg-kawg digital multimeters (tseem hu ua nrov digital multimeters), nruab nrab-ntau digital multimeters, nruab nrab / digital multimeters, digital / analog hybrid meters, digital / analog dual display meters, multipurpose oscilloscopes (digital multimeters, digital storage oscilloscope thiab lwm yam kinetic lub zog hauv ib qho).
Digital Multimeter Test muaj nuj nqi
Cov multimeter tsis tuaj yeem ntsuas DC voltage (DCV), AC voltage (ACV), DC tam sim no (DCA), AC tam sim no (ACA), tsis kam (Ω), diode rau pem hauv ntej voltage poob (VF), thiab transistor emitter tam sim no amplification coefficient (hrg), nws tseem tuaj yeem ntsuas qhov ntsuas hluav taws xob (C), kev coj ua (ns), qhov kub thiab txias (T), zaus (f), thiab ntxiv qib buzzer (BZ) rau kev kuaj kab txuas ntxiv thiab txoj hauv kev siv hluav taws xob tsawg rau kev ntsuas kev tiv thaiv. iav (L0Ω). Qee cov twj paj nruag kuj muaj kev hloov pauv tsis siv neeg rau inductance iav, teeb liab iav, AC / DC, thiab tsis siv neeg hloov pauv ntau yam rau cov iav capacitance.
Feem ntau cov digital digital multimeters tau ntxiv cov haujlwm tshiab hauv qab no thiab kev sim ua haujlwm: nyeem ntawv tuav (TSH), ntsuas kev ntsuas (LOGIC), tus nqi zoo (TRMS), ntsuas tus nqi txheeb ze (RELΔ), tsis siv neeg kaw (AUTO OFF POWER), thiab lwm yam.
Anti-interference muaj peev xwm ntawm digital multimeter
Yooj yim digital multimeters feem ntau siv lub ntsiab lus hloov pauv A / D.
Ntev npaum li lub sijhawm sib koom ua ke rau pem hauv ntej raug xaiv kom sib npaug ntawm qhov sib npaug ntawm qhov sib txawv ntawm lub sijhawm cuam tshuam cuam tshuam, qhov cuam tshuam cuam tshuam tuaj yeem cuam tshuam tau zoo. Qhov no yog vim hais tias tus ntoo khaub lig-nruab nrab cuam tshuam teeb liab yog nruab nrab tawm thaum lub sij hawm rau pem hauv ntej integration theem. Qhov sib piv piv txwv tsis pom zoo (CMRR) ntawm nruab nrab thiab qis-kawg digital multimeters tuaj yeem ncav cuag 86 txog 120dB.
Txoj Kev Loj Hlob ntawm Digital Multimeters
Kev sib xyaw ua ke: Lub handheld digital multimeter siv ib qho-chip A / D converter, thiab peripheral Circuit Court yog qhov yooj yim, tsuas yog yuav tsum muaj ob peb lub chips thiab cov khoom siv. Nrog rau qhov kev tshwm sim tas mus li ntawm ib leeg-chip digital multimeter nplooj siab chips, ib qho kev ua tiav tsis siv neeg ntau yam digital multimeter tuaj yeem tsim tau siv ib qho IC, tsim kom muaj txiaj ntsig zoo rau kev tsim qauv yooj yim thiab txo cov nqi.
Kev siv hluav taws xob tsawg: Cov khoom siv digital tshiab feem ntau siv CMOS loj-scale integrated circuit A/D converters, thiab tag nrho cov hwj huam noj yog tsawg heev.
Kev sib piv ntawm qhov zoo thiab qhov tsis zoo ntawm cov multimeters zoo tib yam thiab digital multimeters:
Analog thiab digital multimeters txhua tus muaj lawv tus kheej qhov zoo thiab qhov tsis zoo.
Analogue multimeter yog ib qho ntsuas nruab nrab nrog qhov kev nyeem ntawv zoo thiab muaj txiaj ntsig. (Feem ntau, tus nqi nyeem ntawv yog ze ze rau lub pointer viav vias lub kaum sab xis, yog li nws yog qhov yooj yim heev).
Digital multimeter yog ib qho cuab yeej tam sim ntawd. Nws yuav siv sij hawm 0.3 vib nas this
Ib qho piv txwv yog siv los qhia cov txiaj ntsig ntsuas. Qee zaum cov txiaj ntsig ntawm txhua qhov piv txwv tsuas yog zoo sib xws tab sis tsis zoo ib yam. Qhov no tsis yooj yim npaum li tus pointer hom nyeem cov txiaj ntsig. Pointer multimeters feem ntau tsis muaj lub amplifier sab hauv, yog li qhov kev tiv thaiv sab hauv me me.
Vim hais tias cov digital multimeter siv lub tshuab hluav taws xob ua haujlwm sab hauv, qhov kev tiv thaiv sab hauv tuaj yeem ua tau loj heev, feem ntau 1M ohm lossis ntau dua. (piv txwv li qhov siab dua tuaj yeem tau txais). Qhov no ua rau qhov cuam tshuam ntawm Circuit Court nyob rau hauv kev sim me me thiab qhov ntsuas qhov tseeb dua.
Vim tias qhov kev tiv thaiv sab hauv ntawm tus pointer multimeter me me, cov khoom sib cais feem ntau yog siv los ua ib qho shunt thiab voltage divider circuit. Yog li ntawd, cov yam ntxwv zaus tsis sib npaug (kwv yees rau digital), thiab cov yam ntxwv zaus ntawm digital multimeters kuj zoo dua. Cov qauv sab hauv ntawm analog multimeter yog qhov yooj yim, yog li nws muaj tus nqi qis dua, kev ua haujlwm tsawg dua, kev saib xyuas yooj yim, thiab muaj zog overcurrent thiab overvoltage peev xwm.
Digital multimeter siv ntau yam oscillation, amplification, zaus division tiv thaiv thiab lwm yam circuits sab hauv, yog li nws muaj ntau yam haujlwm. Piv txwv li, nws tuaj yeem ntsuas qhov kub thiab txias, zaus (hauv qhov qis), capacitance, inductance, ua lub teeb liab generator, thiab lwm yam.
Vim hais tias cov qauv sab hauv ntawm digital multimeters siv cov kev sib txuas sib txuas, lawv muaj peev xwm ua haujlwm tsis zoo thiab feem ntau tsis yooj yim kho tom qab kev puas tsuaj. Digital multimeters muaj qhov tso zis tsawg voltages (feem ntau tsis ntau tshaj 1 volt). Nws tsis yooj yim rau kev sim qee yam khoom siv nrog cov yam ntxwv tshwj xeeb (xws li thyristors, lub teeb-emitting diodes, thiab lwm yam). Cov zis voltage ntawm analog multimeter yog siab dua. Cov tam sim no kuj loj, ua rau nws yooj yim mus kuaj thyristors, lub teeb-emitting diodes, thiab lwm yam.
Beginners yuav tsum siv ib tug analog multimeter, thiab tsis yog-pib pib yuav tsum tau siv ob lub twj paj nruag.
