Kev soj ntsuam yuam kev ntawm Internal Connection Method thiab External Connection Method of Ammeter
Yog tias tus nqi tsis kam ntawm qhov kev tiv thaiv R yuav tsum tau ntsuas me me, qhov kev tiv thaiv tus nqi ntsuas los ntawm kev sib txuas sab nraud yog qhov tseeb dua thiab qhov yuam kev me me; Yog tias tus nqi tsis kam ntawm qhov tsis kam R los ntsuas yog loj, tus nqi kuj ntsuas los ntawm txoj kev sib txuas sab hauv yog qhov tseeb dua.
(1) Thaum siv txoj kev sib txuas sab nraud
Tus naj npawb tso tawm hauv ammeter yuav tsum yog cov lej ntawm IR tam sim no ntws los ntawm R thiab tam sim no IV dhau los ntawm voltmeter, uas yog, I=IR ntxiv rau IV, ces R=U / I{ {2}}U/(IR plus IV)
Qhov ua rau ntawm qhov yuam kev yog tias qhov shunt tam sim no IV ntawm lub voltmeter yog ntxiv rau tam sim no I, thiab vim li ntawd, qhov ntsuas tus nqi ntawm R yog me dua qhov tseeb tus nqi. Txawm li cas los xij, qhov kev tiv thaiv sab hauv RV ntawm qhov dav dav volt charter yog qhov loj, txog ntau txhiab ohms. Yog hais tias qhov kev tiv thaiv R yuav tsum tau ntsuas tsawg dua li qhov kev tiv thaiv sab hauv RV ntawm lub voltmeter, uas yog, R
Qhov txheeb ze yuam kev yog:
Qhov ntau dua qhov kev tiv thaiv sab hauv ntawm voltmeter, qhov me dua qhov txheeb ze yuam kev.
(2) Thaum siv txoj kev sib txuas sab hauv
Tus lej sawv cev voltage U yog sib npaug rau cov lej ntawm qhov voltage UR ntawm ob kawg ntawm R thiab qhov voltage UA ntawm ob qho kawg ntawm ammeter U=UR ntxiv UA, uas yog, ces
The cause of the error is that the voltmeter divider voltage UA is added to the voltage U, and as a result, the measured R value is larger than the actual value. If the resistance value of the resistance R to be measured is much larger than the internal resistance RA of the voltmeter, that is, R>>RA, raws li qhov xwm txheej ntawm kev faib hluav taws xob, UA tuaj yeem tsis quav ntsej. Nws suav hais tias U=UR, thiab cov txiaj ntsig ntsuas yog qhov sib piv.
Qhov txheeb ze yuam kev yog:
Nws tuaj yeem pom tias qhov me me ntawm qhov tsis kam ntawm lub ammeter, qhov me dua qhov txheeb ze yuam kev.
Tus nqi tsis kam ntawm qhov kev tiv thaiv yuav tsum tau kuaj yog txheeb ze rau qhov kev tiv thaiv sab hauv ntawm cov cuab yeej siv. Ib qho ammeter nrog ntau qhov loj muaj qhov me me hauv qhov tsis kam, thiab lub voltmeter nrog ib qho me me muaj qhov loj sab hauv; voltmeter nrog ib tug loj ntau muaj ib tug loj sab hauv kuj, thiab ib tug voltmeter nrog ib tug me me ntau yam muaj ib tug me me nyob rau hauv kuj. Txawm li cas los xij, qhov amperage lossis volts uas sawv cev los ntawm txhua qhov me me ntawm ammeter nrog ntau qhov loj yog qhov loj, thiab nws tsis tuaj yeem nyeem ntau qhov tseem ceeb rau qhov me me tam sim no thiab voltages.
