7-point empirical digital formula rau siv multimeters
1. Ua ntej siv, koj yuav tsum xyuas seb qhov kev hloov pauv hloov pauv puas yog nyob rau hauv txoj haujlwm sib raug rau lub zog ntsuas thiab seb qhov kev xeem coj mus rau hauv cov khoom sib thooj.
2. Raws li qhov yuav tsum tau ua ntawm "hauv av" lossis " xub" cim rau ntawm lub taub hau 'meter', tso lub multimeter vertically lossis horizontally. Yog hais tias tus pointer tsis taw tes rau ntawm qhov pib ntawm qhov ntsuas, lub tshuab xoom txoj hauj lwm yuav tsum tau kho ua ntej.
3. Xaiv qhov tsim nyog raws li qhov ntsuas hluav taws xob. Thaum ntsuas qhov voltage thiab tam sim no, sim deflect tus pointer rau ntau tshaj 1/2 ntawm tag nrho cov nplai, uas tuaj yeem txo qhov kev xeem yuam kev. Yog tias koj tsis paub qhov loj npaum li cas los ntsuas, koj tuaj yeem ntsuas qhov siab tshaj plaws thiab tom qab ntawd maj mam txo qhov ntau kom txog thaum tus pointer deflects ho. Txawm li cas los xij, thaum kuaj qhov hluav taws xob siab (siab tshaj 100 volts) lossis tam sim no loj (tso 0.5 amps), qhov ntau yuav tsum tsis txhob hloov pauv thaum them nyiaj, txwv tsis pub, cov kev sib cuag ntawm qhov hloov pauv tuaj yeem ntes hluav taws thiab hlawv.
4. Thaum ntsuas DC voltage lossis DC tam sim no, xyuam xim rau qhov ntsuas polarity. Yog tias koj tsis paub qhov voltage ntawm ob lub ntsiab lus yuav tsum ntsuas, koj tuaj yeem luv luv kov ob qhov kev sim ua rau ob lub ntsiab lus, txiav txim siab theem ntawm qhov muaj peev xwm raws li kev taw qhia ntawm qhov taw qhia qhov cuam tshuam, thiab tom qab ntawd ntsuas.
5. Thaum ntsuas AC voltage, koj yuav tsum paub seb qhov AC voltage zaus nyob rau hauv qhov ua haujlwm zaus ntawm multimeter. Feem ntau, qhov ntau zaus ua haujlwm ntawm multimeter yog 45-1500Hz. Tshaj li 1500Hz, ntsuas kev nyeem ntawv yuav qis qis. AC voltage scale yog raws li tus nqi zoo ntawm sine yoj, yog li lub multimeter tsis tuaj yeem siv los ntsuas sine yoj voltages xws li daim duab peb sab yoj, square sawtooth tsis, thiab lwm yam. Thaum AC voltage yog superimposed nrog DC voltage, DC blocking capacitor. nrog txaus voltage kuj yuav tsum tau txuas nrog nyob rau hauv series ua ntej ntsuas.
6. Thaum ntsuas qhov hluav taws xob ntawm ib qho kev thauj khoom, nws yog ib qho tsim nyog yuav tau txiav txim siab seb qhov kev tiv thaiv sab hauv ntawm lub multimeter yog ntau npaum li cas ntawm cov khoom ua haujlwm. Yog tias tsis yog, tus nqi nyeem ntawv yuav qis dua tus nqi tiag tiag vim qhov cuam tshuam shunting ntawm multimeter. Lub sijhawm no, lub multimeter tsis tuaj yeem siv los ntsuas ncaj qha thiab yuav tsum tau hloov pauv. Siv lwm txoj kev. Internal resistance ntawm multimeter's voltage block yog sib npaug rau qhov voltage rhiab heev multiplied los ntawm tag nrho-scale voltage tus nqi. Piv txwv li, qhov voltage rhiab heev ntawm MF-30 multimeter ntawm DC100 volt block yog 5 kiloohms, thiab sab hauv tsis kam ntawm multimeter yog 500 kiloohms. Feem ntau hais lus, qhov kev tiv thaiv sab hauv ntawm qhov tsawg-ntau ntau yog me me, thiab kev tiv thaiv sab hauv ntawm qhov siab-ntau ntau yog loj. Thaum siv qhov tsawg-voltage ntau yam los kuaj ib qho hluav taws xob vim qhov me me sab hauv tsis kam thiab cov nyhuv shunt loj, koj tuaj yeem xav hloov mus rau qhov ntsuas siab. Nyob rau hauv txoj kev no, txawm hais tias tus pointer deflects Lub kaum sab xis me me, tab sis vim qhov me me shunting nyhuv, qhov tseeb yuav siab dua. Muaj qhov xwm txheej zoo sib xws thaum ntsuas tam sim no. Thaum lub multimeter yog siv los ua ib qho ammeter, qhov kev tiv thaiv sab hauv me me thaum siv ntau yam loj thiab cov kev tiv thaiv sab hauv me me thaum siv ntau yam me me.
7. Thaum ntsuas qhov tsis kam, xoom hloov yuav tsum tau ua txhua zaus koj hloov lub zog. Tus nqi ntawm qhov chaw geometric ntawm lub multimeter qhov tsis kam ntsuas qhov sib npaug ntawm qhov sib npaug ntawm qhov hluav taws xob thaiv yog qhov nruab nrab tsis kam ntawm qhov thaiv, uas yog sib npaug rau qhov kev tiv thaiv sab hauv ntawm multimeter hauv lub thaiv. Cov nqi nruab nrab nruab nrab suav nrog 8. 10. 12. 13. 16. 20. 24. 25. 30. 60. 75 thiab lwm yam. Qhov ntsuas tsis kam yog non-linear. Thaum siv nws, koj yuav tsum xaiv lub iav uas tsim nyog kom lub pointer point ze ze ntawm qhov chaw li qhov ua tau, feem ntau nyob rau hauv thaj tsam ntawm 0.1Ro-10Ro (Ro----- nruab nrab tsis kam). Kev nyeem ntawv yog qhov tseeb dua. Sab nraud qhov kev ua yuam kev no loj. Piv txwv li, qhov nruab nrab nplai tus nqi ntawm MF10 multimeter yog 13. Thaum Rx10 kilohm block Ro=130 kilohm, qhov thaiv no haum rau ntsuas 13 kiloohm-1. 3 megohm resistor.
