Puas tuaj yeem Digital Multimeters (DMMs) Hloov Analog Multimeters (AMMs)?
Undoubtedly, ib tug multimeter tuaj yeem hais tau tias yog cov cuab yeej siv hluav taws xob uas siv ntau tshaj plaws rau cov neeg siv hluav taws xob, tab sis xaiv ib qho digital multimeter lossis analog (pointer) multimeter yog ib lo lus nug. Qee tus neeg hais tias digital multimeters tau maj mam hloov analog multimeters, tab sis ntau tus kws tshaj lij hluav taws xob tseem tau siv ntau dua los siv analog multimeters. Dab tsi yog qhov sib txawv ntawm digital multimeter thiab analog multimeter? Qhov twg yog qhov zoo dua los siv?
Qhov sib txawv loj tshaj plaws ntawm digital multimeter thiab analog multimeter yog cov zaub ntawm kev nyeem ntawv. Lub multimeter digital yog cov kua siv lead ua kua nrog cov kev daws teeb meem siab, uas tuaj yeem tshem tawm cov parallax thaum nyeem cov ntaub ntawv, ua rau kev nyeem ntawv yooj yim thiab raug. Hauv qhov no, analog multimeters tsis tuaj yeem sib piv, tab sis lawv kuj muaj lawv tus kheej qhov zoo, uas yog lawv muaj peev xwm intuitively xav txog cov kev hloov pauv ntawm cov khoom ntsuas los ntawm qhov deflection instantaneous ntawm tus pointer.
Vim lub fact tias cov multimeters digital ntsuas thiab tso saib hluav taws xob nyob rau hauv ib tug intermittent yam, nws tsis yooj yim los soj ntsuam cov kev hloov tas mus li thiab cov tiam sis ntawm cov ntsuas hluav taws xob. Piv txwv li, digital multimeter tsis yooj yim thiab intuitive li analog multimeter los kuaj cov txheej txheem them nyiaj ntawm cov khoom siv hluav taws xob, qhov hloov pauv ntawm thermistor tsis kam nrog qhov kub thiab txias, thiab kev soj ntsuam cov yam ntxwv ntawm kev hloov pauv ntawm photoresistor tsis kam nrog lub teeb.
Raws li txoj cai ntawm kev ua haujlwm, analog multimeters thiab digital multimeters kuj txawv. Internal qauv ntawm analog multimeters muaj xws li ib tug meter taub hau, ib tug resistor, thiab ib tug roj teeb. Lub taub hau ntsuas feem ntau siv lub tshuab hluav taws xob magneto DC microampere meter. Thaum ntsuas kev tiv thaiv, lub roj teeb sab hauv yuav tsum tau siv, thiab lub davhlau ya nyob twg zoo ntawm lub roj teeb yuav tsum tau txuas nrog lub ntsuas hluav taws xob dub, yog li tam sim no ntws tawm ntawm qhov kev sojntsuam dub thiab mus rau qhov kev sojntsuam liab. Thaum ntsuas DC tam sim no, lub shunt resistor txuas nrog los ntawm kev hloov lub zog kom hloov qhov tam sim no. Txij li thaum tag nrho cov kev tsis ncaj ncees tam sim no ntawm lub 'meter' me me, lub shunt resistor yog siv los nthuav qhov ntau. Thaum ntsuas DC voltage, tus resistor txuas nrog hauv cov koob nrog lub ntsuas lub taub hau, thiab cov khoom sib txawv ntxiv tau siv los ua kom tau txais kev hloov pauv ntawm ntau qhov sib txawv.
Lub multimeter digital yog tsim los ntawm kev hloov pauv muaj nuj nqi, A / D converter, ib qho LCD zaub, lub hwj huam mov, thiab kev hloov pauv hloov pauv hloov pauv, uas feem ntau A / D converter feem ntau siv ICL7106 dual kev koom ua ke hom A / D converter. ICL7106 txais ob qhov sib xyaw ua ke, thawj qhov sib xyaw ua ke ntawm cov tswv yim analog teeb liab V1, hu ua cov txheej txheem sampling; Qhov thib ob kev koom ua ke ntawm qhov siv voltage - VEF kev koom ua ke yog hu ua cov txheej txheem sib piv. Suav ob txoj kev sib koom ua ke siv lub txee binary, hloov lawv mus rau hauv cov lej digital, thiab muab tso rau hauv daim ntawv digital. Txhawm rau ntsuas AC voltage, tam sim no, tsis kam, capacitance, diode rau pem hauv ntej voltage poob, transistor amplification factor, thiab lwm yam khoom siv hluav taws xob, cov converters sib raug yuav tsum tau ntxiv los hloov cov ntsuas hluav taws xob rau hauv DC voltage signals.
Lub polarity ntawm lub roj teeb txuas nrog hauv lub tshuab digital multimeter thiab lub pointer multimeter yog qhov sib txawv: lub digital liab sojntsuam txuas nrog tus ncej zoo ntawm lub roj teeb, qhov kev sojntsuam dub txuas nrog tus ncej tsis zoo, thiab lub pointer hom yog qhov sib txawv. Lub diode ntsuas los ntawm digital meter raws nraim qhov tseeb polarity ntawm diode, thaum lub pointer hom yog qhov txawv.
Hauv kev siv, analog multimeters yog nruab nrog txhua yam xoom hloov kho pob qhov rooj lossis screws. Yog tias nws pom tias tus pointer tsis taw tes rau qhov chaw xoom xoom (xws li xoom taw tes ntawm qhov ntsuas qhov ntsuas hluav taws xob lossis qhov infinity ntawm ohm qhov ntsuas), lub tshuab xoom hloov kho yuav tsum maj mam tig thiab maj mam tig nrog ntiv tes lossis lub hau ntswj kom rov pib lub pointer rau xoom thiab tshem tawm xoom taw tes yuam kev. Digital multimeter muaj qhov tsis siv neeg zeroing muaj nuj nqi, uas yooj yim dua.
