Ntau yam xaiv thiab ntsuas qhov yuam kev Analysis rau Multimeter Range
1. Kev xaiv thiab ntsuas qhov yuam kev ntawm voltage thiab tam sim no ntau yam rau multimeter
Qhov tseeb theem ntawm multimeter feem ntau muab faib ua ntau theem xws li 0.1, 0.5, 1.5, 2.5, thiab 5. Kev ntsuas qhov tseeb (precision) qib rau DC voltage, tam sim no, AC voltage, tam sim no, thiab lwm yam iav yog qhia raws li qhov feem pua ntawm qhov siab tshaj plaws tso cai yuam kev rau tag nrho cov nqi △. Qhia tawm hauv cov mis: A%=(△ X/tus nqi tag nrho) × 100%... 1
(1) Siv multimeters nrog qhov tseeb sib txawv los ntsuas qhov yuam kev tsim los ntawm tib qhov hluav taws xob
Piv txwv li, yog tias muaj 10V tus qauv voltage thiab ob lub multimeters nrog 100V iav, 0.5 qib thiab 15V iav, thiab 2.5 qib yog siv rau kev ntsuas, qhov twg qhov kev ntsuas qhov yuam kev tsawg tshaj plaws?
Kev daws: Los ntawm equation 1: Thawj qhov kev ntsuas: Qhov siab tshaj plaws tsis raug tso cai
△X1=±0.5％×100V=±0．50V.
Kev ntsuas thib ob: qhov siab tshaj qhov tso cai yuam kev
△X2=±2．5％×l5V=±0.375V.
Muab piv △ X1 thiab △ X2, nws tuaj yeem pom tau tias txawm hais tias qhov tseeb ntawm thawj lub 'meter' siab tshaj qhov thib ob 'meter', qhov kev ua yuam kev tshwm sim los ntawm kev ntsuas nrog thawj lub 'meter' loj dua qhov uas tsim los ntawm kev ntsuas nrog lub ntsuas thib ob. Yog li ntawd, nws tuaj yeem pom tias thaum xaiv ib lub multimeter, qhov tseeb dua tsis tas yuav zoo dua. Nrog rau qhov tseeb multimeter, nws tseem yuav tsum tau xaiv qhov tsim nyog. Tsuas yog los ntawm kev xaiv qhov tseeb ntau tuaj yeem siv qhov tseeb ntawm multimeter
(2) Qhov yuam kev tshwm sim los ntawm kev ntsuas tib qhov hluav taws xob nrog ntau qhov sib txawv ntawm multimeter
Piv txwv li, tus MF-30 multimeter muaj qhov tseeb ntawm 2.5. Thaum ntsuas tus qauv voltage ntawm 23V siv 100V lossis 25V lub zog, lub iav twg muaj qhov yuam kev tsawg tshaj plaws?
Kev daws: Qhov siab tshaj plaws tso cai yuam kev rau 100V iav:
X(100)=±2.5％×100V=±2.5V.
Qhov siab tshaj qhov yuam kev rau 25V iav yog △ X (25)=± 2.5% × 25V=± 0.625V. Raws li tuaj yeem pom los ntawm cov kev daws teeb meem saum toj no:
Ntsuas 23V tus qauv voltage nrog 100V iav, thiab kev nyeem ntawv ntawm multimeter yog nyob nruab nrab ntawm 20.5V thiab 25.5V. Ntsuas 23V tus qauv voltage nrog 25V iav, thiab kev nyeem ntawv ntawm multimeter yog nyob nruab nrab ntawm 22.375V thiab 23.625V. Los ntawm cov txiaj ntsig saum toj no, nws tuaj yeem pom tias △ X (100) ntau dua △ X (25), qhia tias qhov ntsuas qhov yuam kev ntawm 100V iav yog qhov loj dua li ntawm 25V iav. Yog li ntawd, thaum ntsuas qhov sib txawv voltages nrog lub multimeter, qhov yuam kev tsim los ntawm kev ntsuas nrog ntau qhov sib txawv tsis zoo ib yam. Thaum ua tau raws li qhov tseem ceeb ntawm cov teeb liab ntsuas, nws raug nquahu kom xaiv cov iav nrog cov kab me me kom ntau li ntau tau. Qhov no tuaj yeem txhim kho qhov tseeb ntawm qhov ntsuas
(3) Qhov yuam kev tshwm sim los ntawm kev ntsuas ob qhov sib txawv ntawm qhov sib txawv ntawm qhov sib txawv ntawm ib qho multimeter
Piv txwv li, tus MF-30 multimeter muaj qhov tseeb ntawm 2.5. Thaum ntsuas tus qauv voltage ntawm 20V lossis 80V hauv 100V ntau yam, qhov twg muaj qhov yuam kev tsawg tshaj plaws?
Kev daws: Qhov siab tshaj qhov yuam kev: △ A%= qhov siab tshaj qhov yuam kev △ X / ntsuas tus qauv voltage hloov kho × 100%, qhov siab tshaj qhov yuam kev △ X (100) hauv 100V iav=± 2.5% × 100V ± 2.5V}
Rau 20V, nws qhov taw qhia yog li ntawm 17.5V txog 22.5V. Qhov siab tshaj qhov txheeb ze yuam kev yog: A (20)%=(± 2.5V/20V) × 100%=± 12.5%
Rau 80V, nws qhov taw qhia yog li ntawm 77.5V txog 82.5V. Qhov siab tshaj qhov txheeb ze yuam kev yog:
A(80)％=±(2.5V/80V)×100％=±3.1％.
