Dab tsi yog dual impedance digital multimeter pab tau rau?
Cov cuab yeej daws teeb meem qub xws li analog multimeters thiab solenoid testers feem ntau muaj qis impedance input circuits ntawm 10 kiloohms lossis tsawg dua. Txawm hais tias cov cuab yeej no yuav tsis raug dag los ntawm cov hluav taws xob tsis raug, lawv tsuas yog siv tau los ntsuas cov hluav taws xob hluav taws xob lossis lwm cov khoom siv hluav taws xob uas tsis tshua muaj impedance uas yuav tsis cuam tshuam lossis hloov kev ua haujlwm hauv Circuit Court.
Los ntawm kev siv cov cuab yeej ntsuas ob lub impedance, cov kws tshaj lij tuaj yeem daws teeb meem rhiab hauv hluav taws xob lossis tswj Circuit Court, nrog rau cov khoom siv hluav taws xob uas yuav muaj cov hluav taws xob tsis raug, thiab kev ntseeg siab dua txiav txim siab seb puas muaj qhov hluav taws xob hauv Circuit Court. Ntawm Fluke 11X series digital multimeter, Vac thiab Vdc hloov txoj haujlwm ntawm qhov ntsuas feem ntau nyob rau hauv txoj haujlwm siab impedance. Cov kev hloov pauv no tuaj yeem siv rau kev daws teeb meem feem ntau, tshwj xeeb tshaj yog rau cov khoom siv hluav taws xob rhiab heev.
Dab tsi yog qhov tsis tseeb voltage? Lawv tshwm qhov twg?
Cov hluav taws xob tsis raug yog los ntawm cov hluav taws xob hluav taws xob thiab cov xaim hluav taws xob tsis muaj zog uas nyob ze rau ib leeg (xws li hauv tib lub kav dej lossis lub cev). Qhov teeb meem no tuaj yeem tsim lub capacitor, uas yuav tsim kom muaj kev sib txuas ntawm lub zog ntawm cov xaim hluav taws xob thiab cov xov hlau uas tsis siv nyob ib sab.
Thaum cov hlau ntawm multimeter muab tso rau nruab nrab ntawm qhov qhib Circuit Court thiab nruab nrab tus neeg xyuas pib, ib qho kev ua tiav Circuit Court yog tsim los ntawm cov tswv yim ntawm multimeter. Lub capacitance ntawm qhov txuas thermal conductor thiab floating conductor yog ua ke nrog cov input impedance ntawm lub multimeter los ua ib tug voltage divider. Lub multimeter mam li ntsuas thiab qhia txog tus nqi hluav taws xob tau txais. Feem ntau cov digital multimeters niaj hnub no muaj qhov muaj peev xwm ua tau zoo txaus los tso saib qhov hluav taws xob txuas hluav taws xob no (yog li muab qhov kev xav tsis tseeb uas tus neeg xyuas pib raug them). Lub multimeter yeej ntsuas qhov voltage txuas mus rau tus neeg xyuas pib disconnected. Tab sis qee zaum, cov hluav taws xob no tuaj yeem ncav cuag 8085% ntawm qhov "hard wired" voltage. Yog tias lawv tsis raug txheeb xyuas tias yog qhov tsis muaj tseeb, nws yuav siv sijhawm ntxiv, kev siv zog, thiab nyiaj txiag hauv kev daws teeb meem hauv Circuit Court.
Feem ntau qhov chaw uas tsis muaj hluav taws xob raug ntsib yog cov tshuab hluav taws xob hauv lub vaj huam sib luag, cov xov tooj tsis siv lossis cov xov hlau nyob hauv cov kav dej uas twb muaj lawm, thiab cov xaim hauv av lossis nruab nrab hauv 1-V ceg circuits lossis cov thawv ntawv uas siv 1- V tswj circuits los tswj cov kab sib dhos lossis kev thauj mus los. Ib qho nyiaj ntawm qhov tsis tseeb voltage tuaj yeem ua ob peb los ntawm sab ntawm lub tshuab fuse mus rau sab qhib. Thaum tsim cov chaw lossis cov tsev thiab ua cov xaim hluav taws xob, cov hluav taws xob feem ntau dhau cov xov hlau txuas ntxiv los ntawm cov kav dej rau kev siv yav tom ntej. Cov xov hlau no feem ntau nyob twj ywm tsis txuas ua ntej siv, tab sis kev sib txuas capacitive yuav tshwm sim. Rau kev tswj Circuit Court, qhov chaw ntawm lub Circuit Court feem ntau yog ze rau cov kab tswj tsis siv, ua rau muaj qhov tsis muaj hluav taws xob.
