Tshwj xeeb nta thiab kev siv ntawm multimeters
Multimeters tau dhau los ua cov cuab yeej tseem ceeb rau cov kws tsim hluav taws xob thiab hluav taws xob vim lawv muaj ntau yam, yooj yim, thiab siv tau yooj yim. Txawm li cas los xij, yog tias ib tus xav siv tag nrho lawv cov haujlwm thiab tau txais cov ntaub ntawv raug sai thiab raug. Tom qab ntawd peb yuav tsum muaj kev nkag siab tob txog qee yam ntawm cov yam ntxwv ntawm multimeter:
Puas yog digital multimeter yuav tsum zoo dua li analog multimeter?
Kev daws: Digital multimeters tau thov sai vim lawv qhov siab precision thiab rhiab heev, ntsuas ceev ceev, ntau lub zog, me me, siab input impedance, kev soj ntsuam yooj yim, thiab kev sib txuas lus muaj zog, ntawm lwm yam zoo heev. Muaj ib txoj hauv kev los hloov cov lus analog pointer.
Tab sis nyob rau hauv tej yam xwm txheej, xws li thaum electromagnetic cuam tshuam muaj zog heev, cov ntaub ntawv kuaj nrog ib tug digital multimeter yuav muaj ib tug tseem ceeb deviation vim hais tias cov input impedance ntawm cov multimeter yog siab heev thiab yog yooj yim cuam tshuam los ntawm induced electromotive quab yuam.
Thaum lub sij hawm tu, nws xav tias los ntawm kev daws teeb meem tias lub diode lossis transistor hauv Circuit Court yuav puas. Tab sis siv cov 'meter' diode ntau yam los ntsuas nws qhov hluav taws xob conduction ntawm li 0.6V, nrog kev coj rov qab tsis kawg. Tsis muaj teeb meem, txawm tias tom qab kuaj xyuas lub Circuit Court, tsis muaj qhov tsis raug. Vim li cas?
Kev daws: Qhov ntsuas hluav taws xob tawm los ntawm cov ntsuas hluav taws xob feem ntau ntawm 3 txog 4.5V. Yog hais tias qhov kev sim transistor muaj me ntsis to los yog tus yam ntxwv nkhaus tau deteriorated, nws yuav tsis tshwm nyob rau hauv xws li tsawg voltage. Nyob rau ntawm lub sijhawm no, nws yog ib qho tsim nyog yuav tsum siv lub ntsuas ntsuas ntsuas nrog qhov tsis kam ntawm 10K, uas tso tawm qhov ntsuas hluav taws xob ntawm 10V lossis 15V. Ntawm qhov ntsuas hluav taws xob no, nws yuav pom tias qhov xav tias transistor muaj qhov xau hauv qhov rov qab. Ib yam li ntawd, thaum ntsuas qhov tsis kam ntawm qee qhov ntsuas qhov ntsuas qhov ntsuas nrog qhov tsis tshua muaj hluav taws xob tsis zoo, siv lub ntsuas ntsuas analog tuaj yeem ua rau cov khoom rhiab heev. Hauv qhov no, lub ntsuas hluav taws xob digital yuav tsum tau siv los ntsuas.
3. Siv ib qho multimeter los ntsuas qhov ntsuas qhov ntsuas hluav taws xob ntawm qhov ntsuas hluav taws xob siab tom qab attenuation, nws tau pom tias qhov ntsuas DCV yog qhov tseeb dua, tab sis qhov yuam kev ACV loj heev. Txawm tias thaum siv multimeter nrog high precision thiab precision, qhov no tseem yog rooj plaub. Qhov no yog vim li cas?
Kev daws: Feem ntau ntawm cov multimeters ntsuas voltage nyob rau hauv parallel, thiab rau tag nrho cov kev xeem Circuit Court, lub voltmeter nws tus kheej yog sib npaug rau ib tug load, uas yog input impedance. Qhov loj dua qhov load impedance, qhov cuam tshuam tsawg dua nws muaj nyob rau ntawm qhov ntsuas hluav taws xob, thiab qhov ntsuas qhov tseeb yuav ntau dua. Tab sis tsis muaj dab tsi tuaj yeem ua tau zoo tag nrho, raws li qhov siab impedance txi lub bandwidth ntawm kev xeem. Tam sim no, input impedance ntawm ib tug multimeter nrog ib tug zaus teb ntawm ib ncig ntawm 100KHz nyob rau hauv lub lag luam yog hais txog 1.1M, yog li nws yuav muaj kev cuam tshuam loj heev thaum kuaj qhov voltage ntawm high-resistance load davhlau ya nyob twg 2, xws li tus nqi siab ntawm kev tiv thaiv. lub high-voltage sojntsuam nws tus kheej. Nyob rau ntawm lub sijhawm no, koj yuav tsum xaiv lub siab nyob sab hauv multimeter, xws li ESCORT 170/172/176/178/179 handheld digital multimeter, uas muab cov input impedance txog li 10000 Ω thaum kuaj ACV, txhawm rau zam qhov no. teeb meem.
4. Hauv kev sim tiag tiag, kuv yuav tsum ntsuas tsis yog qhov voltage thiab tam sim no, lub cev muaj zog winding impedance, thiab lwm yam, tab sis kuj ceev. Puas muaj multimeter uas tuaj yeem ua tiav qhov haujlwm no?
Kev piav qhia: ESCORT-172 handheld digital multimeter tuaj yeem ua tau raws li koj cov kev xav tau saum toj no, thiab nws cov cai tswj kev nyab xeeb ua raws li International Electrotechnical Commission's IEC1010-1 CATII 1000V thiab CATIII 600V cov qauv, yog li koj tuaj yeem siv nrog kev ntseeg siab txawm tias nyob hauv Chav kawm III ib puag ncig yam tsis muaj kev txhawj xeeb txog teeb meem kev nyab xeeb.
5. Puas muaj qhov pheej yig thiab txhim khu kev qha digital multimeter nrog kev ua haujlwm ruaj khov?
Teb: Muaj ib yam zoo hauv ntiaj teb no, thov koj qhia kuv thiab. Txawm li cas los xij, kuj hais lus, cov digital multimeters tsim los ntawm ESCORT hauv Taiwan muaj tus nqi qis dua.
