Hauv kev sib nqus hloov sib nqus, koj tuaj yeem pom cov hlau nplaum sib nqus sib xyaw vibrating raws li qhov ntau zaus ntawm lwm txoj kev sib nqus. Yog tias qhov zaus ntawm qhov chaw hloov pauv tau zoo sib xws nrog cov zaus ntawm cov khoom siv hlau, nws qhov ntau yog qhov loj tshaj plaws, uas yog, cuam tshuam tshwm sim. Cov nyhuv no yog pom tseeb tshwj xeeb rau permalloy (lossis hlau-nickel alloy). Ntawm qhov tod tes, cov nyhuv magnetostrictive no thim rov qab, uas yog, cov nyhuv piezomagnetic.
Yog li no, thaum lub zaus ntawm qhov chaw hloov pauv sib txig sib txuam nrog qhov ceev ntawm cov hlua hlau hauv cov kab cim acousto-sib nqus, cov kab hluav taws xob permalloy pib co. Thaum lub teb sib nqus tau muab tua, lub suab acousto-sib nqus yuav tuav lub damped kev co rau qee lub sijhawm zoo li kev sib dhos, thiab tsim kom muaj lub suab nrov nrov raws li qhov sib txuas ntawm qhov txuas ntawm qhov chaw sib nqus, uas tuaj yeem kuaj tau los ntawm tus txais.
Cov hlau nplaum magnetostriction coefficient λ yog siv los piav qhia txog cov txiaj ntsig magnetostriction, λ=(LH-L0) / L0, L0 yog qhov ntev ntawm cov khoom qub, thiab LH yog qhov ntev ntawm cov khoom siv tom qab hloov pauv nyob rau hauv qhov kev ua ntawm ib qho chaw sib nqus sab nraud. Cov. Vim tias Permalloy muaj cov hlau nplaum loj loj, xws li: Ni50 Permalloy λ=25 × 10-6, Ni80 Permalloy (= (0.1" 0.5) × 10-6, yog li cov hlau nplaum magnetostriction ntawm Permalloy Cov coefficients yog qhov loj dua, thiab cov teeb meem suab nrov. tsim los ntawm cov kab tseem loj dua.