Multimeter electric barrier ntau txoj kev ntsuas thiab yuam kev
Txhua qhov kev tiv thaiv hluav taws xob tuaj yeem ntsuas tus nqi tiv thaiv los ntawm 0 mus rau ∞. Qhov ntsuas qhov ntsuas ntawm ib qho ohmmeter yog qhov tsis-linear, tsis sib xws, inverted scale. Nws yog qhia raws li ib feem pua ntawm lub arc ntev ntawm lub teev. Tsis tas li ntawd, qhov kev tiv thaiv sab hauv ntawm txhua qhov sib npaug yog sib npaug ntawm qhov sib npaug ntawm qhov nruab nrab ntawm tus lej ntawm qhov ntev ntawm qhov ntsuas, uas yog hu ua "central resistance". Qhov ntawd yog hais tias, thaum ntsuas qhov kev tiv thaiv yog sib npaug rau qhov chaw tiv thaiv ntawm qhov kev xaiv, qhov tam sim no ntws hauv Circuit Court yog ib nrab ntawm tag nrho cov ntsuas tam sim no. Tus pointer qhia qhov nruab nrab ntawm qhov ntsuas. Nws qhov tseeb yog qhia los ntawm cov qauv hauv qab no: R feem pua =(△R/center resistance) × 100 feem pua
Thaum siv UNI-T digital multimeter UT33B los ntsuas tib lub zog, qhov yuam kev los ntawm kev xaiv ntau yam
Piv txwv li: MF{{0}} multimeter, lub hauv paus tsis kam ntawm Rxl0 thaiv yog 250Ω; lub hauv paus tsis kam ntawm Rxl 00 thaiv yog 2.5kΩ. Chav kawm raug yog 2.5. Siv nws los ntsuas 500Ω tus qauv tsis kam, thiab nug seb puas yuav ntsuas nws nrog R × l0 iav lossis R × 100 iav, qhov twg muaj qhov yuam kev loj dua?
Tom qab ntawd qhov siab tshaj plaws qhov yuam kev ntawm R × l 0 iav △R (10) =central resistance × R feem pua =250Ω × (± 2.5) feem pua =± 6.25 Ω. Siv nws los ntsuas 500Ω tus qauv tsis kam, ces tus nqi qhia ntawm 500Ω tus qauv tsis kam yog nyob nruab nrab ntawm 493.75Ω{13}}.25Ω. Qhov siab tshaj qhov txheeb ze yuam kev yog: ± 6.25÷500Ω × 100 feem pua =± 1.25 feem pua.
Qhov siab tshaj qhov yuam kev ntawm R × l 00 thaiv △R (100)=nruab nrab tsis kam × R feem pua 2.5kΩ × (± 2.5) feem pua =± 62.5Ω. Siv nws los ntsuas 500Ω tus qauv tsis kam, ces tus nqi qhia ntawm 500Ω tus qauv tsis kam yog nyob nruab nrab ntawm 437.5Ω{14}}.5Ω. Qhov siab tshaj qhov txheeb ze yuam kev yog: ± 62.5÷500Ω × 100 feem pua =± 10.5 feem pua.
Kev sib piv ntawm cov txiaj ntsig ntawm kev suav qhia tau hais tias qhov ntsuas qhov yuam kev sib txawv heev thaum xaiv qhov sib txawv ntawm qhov sib txawv. Yog li ntawd, thaum xaiv lub iav ntau yam, sim ua kom ntsuas qhov ntsuas qhov ntsuas nyob hauv nruab nrab ntawm qhov ntev ntawm qhov ntsuas qhov ntsuas. Qhov ntsuas qhov tseeb yuav siab dua.
