Flux Meter

Lub Flux Meter yog ib qho cuab yeej ruaj khov-sib nqus nrog lub zog txav coilsearch coil txuas nrog lub kauj txav yog qhov ntev lossis luv, thiab vim li ntawd cov cuab yeej siv tau zoo hauv kev sim hlau, qhov twg lub sij hawm siv rau lub flux kom vau lossis thim rov qab yuav yog ob peb feeb. . Lub deflection yog nyeem los ntawm thawj txoj hauj lwm ntawm tus taw tes rau ntawm lub quadrant scale thaum tus pointer mus txog nws qhov siab tshaj plaws deflection; Tom qab no tus pointer drifts maj mam rov qab mus rau ib tug xoom txoj hauj lwm. Ib tug raug tag nrho-scale deflection yuav muab los ntawm kev hloov ntawm 10 μWb-t.

Muaj zog huab cua-qhov sib txawv flux densities tuaj yeem ntsuas los ntawm lwm txoj hauv kev uas lub kauj me me tig ntawm qhov siab thiab paub ceev, qhov induced emf yog proportional to the local flux density.

Sib nqus induction siv
Sib nqus induction siv lub cev yog siv los piav qhia txog cov khoom ntawm magnetic teb, qhia los ntawm B, kev taw qhia ntawm B ntawm ib qho chaw hauv magnetic teb yog cov kev taw qhia ntawm magnetic teb ntawm qhov taw tes, thiab qhov loj ntawm B qhia qhov loj. lub zog ntawm magnetic teb ntawm qhov taw tes.

Hauv SI system ntawm units (International System of Units), chav tsev ntawm magnetic induction zog yog [volts · thib ob / meter 2], thiab [volts] · [thib ob] hu ua Weber, yog li chav tsev ntawm magnetic induction zog yog hu ua [Weber / meter 2] lossis [Tesla], hu ua [T], nyob rau hauv CGSM system ntawm units, chav tsev ntawm magnetic induction zog yog [Gauss]. Cov units yog denoted los ntawm cov cim: V yog [volts], s yog [seconds], m yog [meters], Wb yog [Weber], T yog [T], Gs yog [Gauss], mT yog [millite].
1T=1Wb/m2=104Gs=103mT (1)

Magnetic line of force, magnetic flux thiab magnetic flux continuity theorem
Sib nqus teb yog depicted graphically nrog magnetic teb kab. Cov kab hluav taws xob sib nqus ntawm ntau qhov chaw sib nqus uas tsim los ntawm tam sim no tau qhia hauv daim duab 1. Cov kab hlau nplaum sib nqus yog cov kab tsis muaj taub hau thiab tailless kaw cov kab nyob ib puag ncig tam sim no, thiab cov kev taw qhia ntawm tam sim no thiab cov kev taw qhia ntawm rov qab ntawm magnetic teb kab ua raws li sab xis. txoj cai.

Peb qhia kom meej tias cov kev taw qhia tangent ntawm ib qho taw tes ntawm cov kab hlau nplaum yog cov kev taw qhia ntawm lub magnetic teb (piv txwv li, B) ntawm qhov taw tes, thiab cov naj npawb ntawm cov kab hlau nplaum hauv ib cheeb tsam perpendicular rau B vector yog sib npaug rau Qhov loj ntawm B vector ntawm qhov ntawd. Nyob rau hauv lwm yam lus, nyob rau hauv lub magnetic teb yog muaj zog, lub magnetic teb kab yog denser, thiab qhov chaw magnetic teb tsis muaj zog, lub magnetic teb kab yog thinner.

Tag nrho cov kab ntawm magnetic quab yuam dhau los ntawm ib qho chaw hu ua magnetic flux hla saum npoo thiab yog sawv cev los ntawm Φ. Kev suav ntawm magnetic flux yog pom nyob rau hauv daim duab 2. Lub cheeb tsam yog coj mus rau qhov chaw, thiab ib tug θ Lub kaum sab xis yog tsim los ntawm cov kev taw qhia ntawm nws ib txwm kab thiab cov kev taw qhia ntawm B ntawm lub point. Qhov sib nqus flux ntawm lub caij dhau los ntawm cheeb tsam yog:
dφ{0}}B × cosθ × ds (2)

Yog li tag nrho flux ntawm S los ntawm qhov chaw yog
φ=# B×cosθ×ds (3)

Thaum B yog ib yam thiab S yog dav hlau thiab perpendicular rau B, cov hlau nplaum flux los ntawm S dav hlau yog:
φ = B×S (4)

Qhov no yog kev sib raug zoo uas feem ntau siv hauv kev ntsuas magnetic.
Nruam flux theorem: Thaum S-plane yog qhov chaw kaw, vim tias cov kab hlau nplaum sib nqus yog ib txoj kab kaw, ces cov kab hlau nplaum sib nqus los ntawm qhov chaw kaw yuav tsum dhau los ntawm lwm qhov ntawm qhov chaw kaw, yog li tag nrho cov hlau nplaum sib nqus los ntawm txhua qhov chaw kaw yuav tsum sib npaug rau xoom. Kom txawj ntse:
φ=# Bcosθds=0 (5)

Chav tsev ntawm magnetic flux yog [Weber] nyob rau hauv SI system ntawm units, [Maxwell] nyob rau hauv lub CGSM system ntawm units, thiab lub abbreviation [Mai] cim yog sawv cev los ntawm Mx.
1Wb=108Mx (6)

Sib nqus teb lub zog, permeability thiab ampere-loop txoj cai
Sib nqus teb lub zog yog lub cev muaj nuj nqis qhia los pab txhawb kev tsom xam ntawm kev sib raug zoo ntawm magnetic teb thiab tam sim no, nws kuj yog vector, qhia los ntawm H, nws kev sib raug zoo nrog sib nqus induction siv:
H = B/μ (7)
Qhov twg: μ yog qhov permeability ntawm qhov nruab nrab sib nqus, txiav txim siab los ntawm qhov xwm txheej ntawm cov khoom sib nqus
Pom zoo. Hauv SI units, permeability ntawm lub tshuab nqus tsev yog:
μ0=4π × 10-7 Henry/m (8)

Chav tsev ntawm H yog [ampere / meter], nyob rau hauv CGSM system ntawm units, permeability ntawm lub nqus tsev vacuum yog 1, thiab chav tsev ntawm H yog [Oster], luv rau [Ao]. Cov units tau sawv cev los ntawm cov cim: A yog [ampere], Oe yog [O], thiab H yog [Henry].
1A/m=4π × 10-3 Oe (9)

Ampere txoj cai voj voog: Nyob rau hauv ib qho chaw sib nqus, H vector ua raws li txoj cai kaw
Cov kab ib feem ntawm sigma yog sib npaug rau cov lej algebraic ntawm cov dej tam sim no nyob rau hauv qhov nkhaus kaw. Kom txawj ntse:
# H×cos ×dl=∑I (10)
Qhov twg: yog lub kaum sab xis ntawm qhov kev taw qhia tangent ntawm txoj kab nkhaus thiab qhov sib nqus ntawm qhov taw tes.

Los ntawm kev siv txoj cai Ampere-loop, peb tuaj yeem yooj yim xam cov magnetic teb generated los ntawm ib tug tam sim no nrog ib tug tej yam spatial symmetry. Piv txwv li, xam qhov sib nqus lub zog ntawm P point nyob rau hauv ib tug uniformly tightly mob lub voj voog solenoid, raws li qhia nyob rau hauv daim duab 4. Siv lub concentric vojvoog ntawm lub vojvoog r los ntawm point P raws li lub kaw integral nkhaus. Vim yog kev sib raug zoo, lub zog sib nqus ntawm txhua qhov chaw nyob ib ncig ntawm lub voj voog concentric yog sib npaug, thiab cov kev taw qhia ntawm lub magnetic teb lub zog yog raws li tangent kev taw qhia ntawm lub concentric lub voj voog, uas yog,=0, yog li:
# H×cos ×dl=H*2πr=NI (11)
Yog li lub zog sib nqus ntawm qhov taw tes P: H=NI/ (2πr)

Qhov twg N yog tus naj npawb ntawm winding lem. Los ntawm qhov kev sib raug zoo no, nws tuaj yeem pom tias lub zog ntawm cov hlau nplaum tsuas yog txiav txim siab los ntawm kev faib tawm ntawm qhov tam sim no uas tsim cov hlau nplaum, thiab tsis muaj dab tsi cuam tshuam nrog cov khoom ntawm cov khoom sib nqus.