Cov ntsiab cai ntawm kev khiav hauj lwm thiab cov yam ntxwv ntawm Digital Multimeters:
Cov qauv yooj yim ntawm ib txwm digital multimeter yog qhia hauv daim duab. Lub dual kev koom ua ke A / D converter yog "lub siab" ntawm ib tug digital multimeter, uas enables hloov pauv ntawm analog rau cov teeb liab. Cov kab hluav taws xob peripheral feem ntau suav nrog kev hloov pauv kev ua haujlwm, kev ua haujlwm thiab ntau yam kev xaiv hloov, LCD lossis LED cov lus qhia, nrog rau buzzer oscillation circuits, tsav circuits, nrhiav pom Circuit Court on/off circuits, low voltage indication circuits, decimal point and symbol (polarity symbol, etc.) tsav circuits.
Lub A/D converter yog lub hauv paus ntawm ib tug digital multimeter, siv ib tug ib-chip loj-scale integrated circuit 7106. 7106 txais yuav ib tug internal XOR rooj tso zis, uas yuav tsav LCD zaub thiab txuag electrode noj. Nws cov yam ntxwv tseem ceeb yog: ib qho fais fab mov, qhov ntau qhov hluav taws xob, siv 9V stacked roj teeb kom ua tiav cov khoom siv me me, siab input impedance, thiab siv cov keyboards hauv analog kom ua tiav tsis siv neeg zeroing thiab polarity conversion. Qhov tsis zoo yog qhov kev hloov pauv A / D qeeb, tab sis nws tuaj yeem ua tau raws li cov kev xav tau ntawm cov qauv ntsuas hluav taws xob.
Los ntawm kev siv cov cuab yeej impedance dual, cov kws tshaj lij tuaj yeem * * teeb meem rhiab hauv hluav taws xob lossis kev tswj xyuas Circuit Court, nrog rau cov kev ua txhaum uas yuav suav nrog cov hluav taws xob tsis zoo, thiab tuaj yeem txiav txim siab ntau dua seb puas muaj hluav taws xob hauv Circuit Court.
Rau cov qauv ntsuas hluav taws xob, feem ntau nws yog qhov zoo dua los siv cov twj paj nruag siab impedance tshwj tsis yog tias muaj qhov tsis muaj zog tam sim no.
Hauv Fluke114, 116, thiab 117DMM, muaj qhov cuam tshuam tseem ceeb hauv kev siv Vac thiab Vdc hloov txoj haujlwm ntawm cov cuab yeej, uas tuaj yeem siv los daws cov haujlwm hauv feem ntau, tshwj xeeb tshaj yog rau cov khoom siv hluav taws xob rhiab heev. Qhov qis impedance muaj nuj nqi ntawm Fluke hu ua Auto-V / LoZ. Ntawm lawv, Auto-V sawv cev rau qhov tsis siv neeg voltage, uas tuaj yeem txiav txim siab seb lub teeb liab ntsuas puas yog AC voltage lossis DC voltage, thiab tom qab ntawd xaiv qhov muaj nuj nqi thiab ntau yam los tso saib cov ntaub ntawv raug. LoZ sawv cev rau qis impedance (Z). Qhov kev ua tau zoo no yog qhov tsis muaj impedance input rau qhov ntsuas hluav taws xob, uas tuaj yeem txo qhov muaj peev xwm ntawm kev nyeem ntawv yuam kev tshwm sim los ntawm qhov tsis muaj zog voltages thiab txhim kho qhov tseeb ntawm kev txiav txim siab muaj lossis tsis muaj qhov hluav taws xob. Thaum muaj kev tsis ntseeg txog kev nyeem ntawv (tejzaum nws yog vim qhov tsis txaus ntseeg) lossis thaum ntsuas qhov muaj qhov hluav taws xob, Auto-V / LoZ hloov txoj haujlwm ntawm DMM tuaj yeem siv.
