Dab tsi ntawm multimeter kuv xav tau rau tsheb?
Automotive multimeters kuj hu ua multimeters. Ob lub ntsiab multimeters hauv khw niaj hnub no yog pointer multimeter thiab digital multimeters. Multimeter tau ua tiav kev ntsuas kev ua haujlwm, kev ua haujlwm yooj yim thiab nqa tau yooj yim, thiab tau dhau los ua ib qho ntawm cov cuab yeej siv hluav taws xob thiab hluav taws xob ntsuas. Nws tseem yog qhov tseem ceeb hauv lwm qhov kev lag luam, xws li kev saib xyuas hluav taws xob, kev sib txuas lus cov cuab yeej siv thiab kev kho tsheb, tshwj xeeb tshaj yog cov kws hluav taws xob, hluav taws xob pib thiab cov neeg nyiam xov tooj cua. Kev paub txog kev siv thiab kev txawj ntse ntawm multimeter yog lub hauv paus rau kev txiav txim siab sai ntawm cov khoom zoo thiab kuaj xyuas seb lub Circuit Court (los yog Circuit Court) ntawm cov khoom siv hluav taws xob yog qhov qub. Niaj hnub no, cov cuab yeej ntsuas digital tau dhau los ua qhov tseem ceeb thiab nyiam hloov cov cuab yeej analog. Piv nrog cov cuab yeej analog, cov cuab yeej digital muaj qhov rhiab heev, muaj qhov raug siab, pom meej meej, muaj zog tshaj qhov muaj peev xwm, nqa tau yooj yim thiab siv yooj yim.
Digital multimeter ua tiav qhov ntsuas raws li kev hloov pauv ntawm analog thiab digital kom muaj nuj nqis, thiab nws tuaj yeem tso saib cov txiaj ntsig ntsuas digitally. Qhov yuam kev ntawm digital multimeter hauv kev ntsuas qhov tsis kam yog me dua li ntawm analog multimeter, tab sis qhov txheeb ze yuam kev tseem loj heev thaum nws siv los ntsuas qhov tsis kam nrog me me. Muaj ntau ntau hom digital multimeter, tab sis lub vaj huam sib luag layout yog tib yam, nrog rau cov zaub screen, lub hwj chim hloov, muaj nuj nqi xaiv hloov thiab stylus jack (lub luag hauj lwm ntawm jack tej zaum yuav txawv nrog txawv qauv).
Cov yam ntxwv thiab cov ntaub ntawv kev nyab xeeb ntawm digital multimeter
(1) siv cov cuab yeej ntsuas digital
Digital multimeter txais cov cuab yeej ntsuas digital, hloov cov ntsuas ntsuas analog rau hauv cov lej los ntawm AD converter, thiab thaum kawg tso tawm nws raws li qhov muaj nuj nqis digital. Ntev npaum li lub 'meter' tsis dhia, qhov ntsuas qhov tshwm sim yog qhov tshwj xeeb, uas tsis tsuas yog ua kom lub hom phiaj thiab qhov tseeb ntawm kev nyeem ntawv, tab sis kuj ua raws li tib neeg txoj kev nyeem ntawv. Cov txiaj ntsig tau pom meej meej ntawm ib nrais muag, thiab nws yuav tsis tshwm sim qhov ntsuas qhov yuam kev zoo li analog multimeter.
(2) kua siv lead ua kua zaub
Thaum ntxov digital multimeters feem ntau siv cov kua siv lead ua kua (LCD) nrog lo lus qhov siab ntawm 12.5 hli. Tam sim no, txhawm rau txhim kho cov zaub kom pom tseeb, feem ntau cov digital multimeters siv lub LCD loj loj nrog lo lus siab ntawm 18mm, thiab DT940C, DT960T, DT970, DT980 thiab DT9205 siv super-loj LCD nrog lo lus siab ntawm 25 hli.. Feem ntau ntawm cov tshiab digital multimeters tau ntxiv cov cim ua haujlwm, xws li cov cim mV, V, kV, μA, mA, A, ω, kω, mω, nS, kHz, pF, nF, μF, thiab cov khoom ntsuas cov cim AC, DC .
(3) Kev ntsuas dav dav
Tam sim no, kev ntsuas ntau yam ntawm cov digital multimeter tshiab yog dav dua li ntawm analog multimeter, xws li ntsuas ntau yam ntawm qhov tsis kam (Ω) yog {{0}}.01 ~ 20MΩ (los yog 200mΩ ); Kev ntsuas ntau ntawm DC voltage ntau (DCV) yog 0.2 ~ 1000 V; Kev ntsuas ntau ntawm AC voltage ntau (ACV) yog 0.01 ~ 700V (los yog 750 V); Kev ntsuas ntau ntawm zaus band (F) yog 10Hz ~ 20kHz (los yog 200kHz).
(4) siab raug
Qhov tseeb (precision) ntawm digital multimeter yog ntau dua li ntawm analog multimeter. Vim tias qhov tseeb ntawm digital multimeter yog qhov sib xyaw ua ke ntawm kev ua yuam kev thiab qhov yuam kev random hauv qhov ntsuas ntsuas, nws qhia qhov sib xws ntawm qhov ntsuas qhov tshwm sim thiab qhov tseeb tus nqi (tus qauv tus nqi) thiab tuaj yeem cuam tshuam qhov ntsuas qhov yuam kev. Feem ntau, qhov tseeb dua, qhov me me ntawm qhov ntsuas qhov yuam kev.
(6) Kev daws teeb meem siab
Kev daws teeb meem yog lub peev xwm ntawm digital multimeter kom paub qhov txawv ntawm qhov ntsuas me me. Nws qhia txog qhov rhiab heev ntawm qhov ntsuas, thiab qhov kev daws teeb meem ntawm qhov ntsuas yog qhov sib txawv ntawm qhov sib txawv. Qhov kev daws teeb meem ntawm qhov ntsuas hauv qhov ntau yog txhais raws li qhov ntsuas ntsuas ntawm digital multimeter.
Qee zaum, qhov kev daws teeb meem kuj yog hu ua qhov rhiab heev ntawm qhov ntsuas. Qhov kev daws teeb meem ntawm cov cuab yeej digital nce nrog qhov nce ntawm cov lej tso saib.
Kev daws teeb meem kuj tseem tuaj yeem qhia los ntawm kev daws teeb meem. Kev daws teeb meem yog hais txog qhov feem pua ntawm cov lej lej uas tuaj yeem pom los ntawm qhov ntsuas. Piv txwv li, DT{{0}}/2 tus lej digital multimeter tuaj yeem tso saib tus lej lej li 1 thiab tus lej li xyoo 1999, yog li qhov kev daws teeb meem sib npaug li 1/1999 ≈ 0.05%.
Nws yuav tsum tau taw qhia tias kev daws teeb meem txawv ntawm kev daws teeb meem;
Piv txwv li, qhov kev daws teeb meem ntawm 31/2-ntsis thiab 33/4- cov twj paj nruag yog tib yam, ob qho tib si yog 100μV, tab sis lawv txawv.
Kev daws teeb meem thiab qhov tseeb yog ob lub ntsiab lus sib txawv. Kev daws teeb meem sawv cev rau "kev lees paub" lub peev xwm ntawm cov cuab yeej rau cov cim me me, uas yog, "rhiab heev", thaum qhov tseeb qhia txog "qhov tseeb" ntawm kev ntsuas, uas yog, qhov sib xws ntawm qhov ntsuas qhov ntsuas thiab qhov tseeb qhov tseem ceeb. Ob qho no tsis tas yuav muaj feem cuam tshuam thiab tsis tuaj yeem tsis meej pem. Qhov tseeb, qhov kev daws teeb meem tsuas yog cuam tshuam nrog tus lej ntawm tus lej tso tawm hauv qhov ntsuas, thaum qhov tseeb muaj feem cuam tshuam nrog kev ua yuam kev ntau thiab qhov yuam kev ntawm A / D converter thiab muaj nuj nqi converter hauv lub ntsuas. Hauv kev siv tswv yim, qhov siab dua qhov tseeb thiab rhiab heev, qhov zoo dua, tab sis kuj nyob ntawm cov khoom tshwj xeeb uas yuav tsum tau ntsuas, txwv tsis pub nws kuj yog pov tseg.
