Dab tsi yog cov kev ntsuas thiab ntsuas txoj hauv kev ntawm digital multimeter
1. Kev daws teeb meem, lo lus suav thiab cov khoom siv
Kev daws teeb meem yog hais txog lub peev xwm ntawm multimeter kom paub qhov txawv me me thaum ntsuas. Paub txog qhov kev daws teeb meem ntawm multimeter tso cai rau koj los txiav txim seb nws puas tuaj yeem soj ntsuam cov kev hloov me me hauv cov teeb liab ntsuas. Piv txwv li, yog tias DMM muaj kev daws teeb meem ntawm 1mV ntawm 4V ntau, nws txhais tau tias nws tuaj yeem pom qhov hloov pauv ntawm 1mV (1/1000 ntawm V) thaum nyeem 1V.
Yog tias koj yuav tsum ntsuas qhov ntev mus rau qhov tsawg kawg nkaus ntawm 1/4 nti (lossis 1 hli), koj yuav tsis yuav tus kav nrog qhov tsawg kawg nkaus ntawm 1 nti (lossis 1 cm). Tus pas ntsuas kub uas ntsuas tag nrho cov degrees tsis siv ntau yog tias qhov kub ib txwm yog 98.6 degrees Fahrenheit. Koj xav tau tus pas ntsuas kub nrog qhov kev daws teeb meem ntawm 0.1 degrees.
Cov lus "ntsis" thiab "cov lus" yog siv los piav qhia txog kev daws teeb meem ntawm multimeter. Lawv tuaj yeem muab faib ua pawg los ntawm cov lus lossis tus lej tso tawm los ntawm DMM.
Ib tug 3½-digit multimeter qhia peb tus lej tag nrho (0 rau 9) thiab "ib nrab tus lej" (tsuas pom "1" lossis tso nws tseg). Ib tug 3½-tus lej multimeter muaj qhov kev daws teeb meem siab txog 1,999 suav. Ib tug 4½-tus lej multimeter muaj qhov kev daws teeb meem txog li 19,999 suav. Piv nrog rau "ntsis", siv "cov lus" tuaj yeem piav qhia meej txog qhov kev daws teeb meem ntawm multimeter. Niaj hnub no 3½-tus lej multimeters yuav muaj kev daws teeb meem siab txog 3,200, 4, 000, lossis 6, 000 suav.
Rau qee qhov kev ntsuas, 3,200 suav multimeter muab kev daws teeb meem zoo dua. Piv txwv li, yog tias koj ntsuas 200V lossis ntau dua, 1, 999- lej multimeter ntsuas tsis tau 0.1V. Thiab 3,200M multimeter tuaj yeem tso saib txog 0.1V thaum ntsuas qhov hluav taws xob mus txog 320V. Qhov kev daws teeb meem no zoo ib yam li tus nqi kim dua 20, 000 suav multimeter kom txog thaum qhov hluav taws xob ntau tshaj 320V.
2. Qhov tseeb
Qhov tseeb yog qhov ua yuam kev siab tshaj plaws raws li kev ua haujlwm tau teev tseg. Hauv lwm lo lus, qhov tseeb qhia tau hais tias kaw qhov ntsuas qhov ntsuas tau pom los ntawm digital multimeter yog rau tus nqi tiag tiag ntawm lub teeb liab ntsuas.
Qhov tseeb ntawm digital multimeter feem ntau yog qhia raws li feem pua ntawm kev nyeem ntawv. Qhov tseeb ntawm 1 feem pua ntawm kev nyeem ntawv txhais tau hais tias yog qhov kev nyeem pom yog 100V, tus nqi tiag tiag ntawm qhov hluav taws xob tuaj yeem nyob qhov twg ntawm 99V thiab 101V.
Cov kev qhia tshwj xeeb kuj tseem suav nrog ntau qhov me me ntxiv rau qhov tseeb qhov tseeb. Qhov ntau yog sawv cev rau tus lej ntawm cov lus uas tus lej zoo tshaj plaws ntawm tus nqi tso tawm yuav txawv. Yog li, qhov tseeb hauv qhov piv txwv saum toj no tuaj yeem qhia tau tias "± (1 feem pua ntxiv 2)". Yog li ntawd, yog tias cov zaub nyeem 100V, qhov tseeb voltage tus nqi yuav nyob nruab nrab ntawm 98.8V thiab 101.2V.
Cov tsis muaj analog multimeter yog txiav txim los ntawm tag nrho-scale yuam kev, tsis yog los ntawm feem pua ntawm cov ntawv nyeem. Qhov tseeb qhov tseeb rau analog multimeters yog ± 2 feem pua lossis ± 3 feem pua ntawm tag nrho cov nplai. Ntawm 1/10 qhov ntsuas tag nrho, qhov tseeb hloov mus rau 20 feem pua lossis 30 feem pua ntawm kev nyeem ntawv. Qhov tseeb qhov tseeb ntawm DMM yog raws li ± (0.7 feem pua ntxiv 1) rau ± (0.1 feem pua ntxiv 1) ntawm kev nyeem ntawv lossis zoo dua.
3. Ohm txoj cai
Qhov voltage, tam sim no, thiab tsis kam ntawm ib lub voj voog tuaj yeem suav nrog Ohm txoj cai, uas hais tias "voltage sib npaug tam sim no lub sij hawm tsis kam" (saib daim duab 1). Yog li ntawd, yog tias muaj ob qhov tseem ceeb hauv cov qauv no paub, tus nqi thib peb tuaj yeem pom.
Digital multimeters siv Ohm txoj cai los ntsuas ncaj qha thiab tso saib tsis kam, tam sim no lossis voltage. Cov hauv qab no piav qhia yuav ua li cas siv digital multimeter kom yooj yim ntsuas qhov yuav tsum tau ua.
4. Digital thiab analog zaub
Cov zaub digital muaj qhov tseeb thiab daws teeb meem, qhia peb lossis ntau tus lej rau txhua qhov kev ntsuas.
Lub koob yees duab analog koob yees duab tsis tshua muaj tseeb thiab muaj qhov kev daws teeb meem qis dua vim tias tus nqi ntawm ob lub zuam yuav tsum kwv yees.
Ib daim duab qhia pom cov teeb liab hloov pauv thiab cov qauv zoo li rab koob analog, tab sis muaj zog dua thiab tsis tshua muaj kev puas tsuaj.
