Yuav ua li cas kom raug ntsuas capacitance nrog tus pointer multimeter
Peb feem ntau siv multimeter los xyuas qhov zoo ntawm cov capacitors thaum lub sij hawm kho hluav taws xob. Cov txheej txheem ib txwm muaj yog kom them thiab tso tawm cov capacitors ntawm tib tus qauv, uas tsis yooj yim rau kev khiav lag luam. Qee cov capacitors, vim lawv cov pins luv thiab muaj peev xwm loj, qee zaum tsis tuaj yeem kuaj nrog digital multimeter. Hauv kuv txoj kev saib xyuas mus sij hawm ntev, tus kws sau ntawv tau tsim ib txoj kev sim yooj yim thiab siv tau. Ntawm no yog ib qho kev qhia, vam tias yuav coj tau yooj yim rau cov npoj yaig.
Hauv kev ntsuas hluav taws xob, muaj ob hom ammeters nrog cov qauv zoo ib yam. Ib hom yog qhov cuam tshuam ammeter. Nws yog ib qho cuab yeej precision siv los ntsuas qhov hluav taws xob kom muaj nuj nqis ntawm cov mem tes tam sim no. Thaum lub sijhawm ntawm cov mem tes tam sim no ntws los ntawm qhov cuam tshuam ammeter luv dua li lub sijhawm dawb oscillation ntawm qhov cuam tshuam ammeter koob, qhov siab tshaj plaws deflection amplitude ntawm rab koob yog ncaj qha proportional rau cov hluav taws xob ntau ntawm cov mem tes tam sim no, yog li linearly ntsuas hluav taws xob. kom muaj nuj nqis ntawm cov mem tes tam sim no. Lwm hom yog rhiab ammeter, thiab lub taub hau ntawm pointer multimeter yog rhiab ammeter. Thaum ntsuas capacitance siv qhov kev tiv thaiv ntau ntawm tus pointer multimeter, lub mem tes them tam sim no yuav raug tsim tawm. Yog tias lub sijhawm ntawm cov mem tes tam sim no luv dua li lub sijhawm dawb oscillation ntawm tus taw tes rau ntawm lub taub hau 'meter', lub taub hau ' meter ' yuav hloov los ntawm ammeter rhiab rau qhov cuam tshuam ammeter, thiab qhov siab tshaj plaws deflection amplitude ntawm tus pointer, Am, yog proportional. rau tus nqi hluav taws xob Q them los ntawm pulse tam sim no rau lub capacitor. Thiab qhov hluav taws xob ntau ntawm lub capacitor Q=CE, E yog lub roj teeb hluav taws xob hluav taws xob ntawm qhov tsis kam, uas yog tus nqi tas li, yog li Q yog ncaj qha proportional rau lub capacitance C, thiab qhov siab tshaj plaws deflection amplitude ntawm lub 'meter'. koob Am kuj yog ncaj qha proportional rau lub capacitance C. Raws li txoj cai no, nws muaj peev xwm ntsuas capacitance siv linear nyeem. Qhov kev tiv thaiv ntawm tus pointer multimeter ua tau raws li cov cai saum toj no thaum deflected ntawm lub kaum sab xis me me, yog li nws tuaj yeem ntsuas qhov ntsuas qhov tseeb.
Noj MF500 multimeter ua piv txwv, kab lus no piav qhia txog txoj hauv kev thiab kev siv ntxiv qhov ntsuas qhov ntsuas. Lub dial ntawm MF500 multimeter yog qhia hauv daim duab. Xaiv 10 lub hlwb me me nyob rau sab laug kawg ntawm DC cov kab sib npaug raws li cov kab tawm kab rau kev ua haujlwm. Qhov no yog vim nws muaj peev xwm ua tau raws li cov kab mob ntawm lub kaum sab xis me me deflection thiab pab txhawb kev nyeem ntawv. Tshaj li 10 daim phiaj, qhov ntsuas yuav maj mam ua tsis-linear. Siv lub capacitor tshiab, xws li lub capacitor nrog tus nqi nominal ntawm 3.3F, thiab siv lub tshuab multimeter los ntsuas nws qhov peev xwm ntawm 3.61F. Ntsuas qhov R ntawm 500 hom multimeter × Zero lub ohm hauv thawj iav. Tom qab tso tawm lub capacitor nrog lub hau ntawm qhov kev sojntsuam, siv ob qhov kev sojntsuam los tiv tauj ob tus ncej ntawm lub capacitor thiab saib xyuas qhov siab tshaj plaws deflection amplitude ntawm qhov kev sojntsuam. Rov qab siv R × 10. R × 100, R × 1k, R × Rov ua cov kauj ruam saum toj no rau 10k iav kom pom cov iav twg muaj qhov siab tshaj plaws deflection hauv 10 kab sib chaws. Qhov tshwm sim hauv R × Ntawm 1k iav, qhov siab tshaj plaws deflection ntawm koob saib yog 3 daim phiaj me me, siv 3.6 μ Faib F los ntawm 3 daim phiaj me me yields capacitance rhiab heev ntawm 1.2F / kab sib chaws rau RX1k iav. Tsuav qhov capacitance rhiab heev ntawm ib lub iav yog ntsuas, qhov rhiab heev ntawm lwm cov iav tuaj yeem suav tau. Qhov rhiab heev ntawm qhov sib piv ntawm qhov sib piv siab yog siab, thaum lub rhiab heev ntawm qhov sib piv qis qis, thiab kev sib raug zoo ntawm cov iav uas nyob ib sab yog recursively 10 zaug. Yog li lub capacitance rhiab heev ntawm qhov tsis kam ntawm MF500 multimeter yog raws li nram no: RX1 ntau -1200F/grid, R × 10 zog 1201F/grid, R × 100 zog -12F daim phiaj. R × 1k iav -1.2F/grid. Rx10k iav -0.12F (120nF)/grid.
