Video: Koj pom qhov wavelength ntawm ultrasound li cas?
2024 Tus sau: Miles Stephen | [email protected]. Kawg hloov kho: 2023-12-15 23:36
Ib txoj hauv kev yooj yim los xam cov wavelength hauv cov ntaub so ntswg yog tsuas yog faib 1.54 hli (qhov kev nthuav tawm ceev ntawm cov ntaub so ntswg) los ntawm qhov zaus hauv MHz. Piv txwv. Nyob rau hauv cov ntaub so ntswg, ib tug mem tes nrog ib zaus ntawm 2.5MHz muaj a wavelength ua 0.61mm.
Ib yam li ntawd, tib neeg nug, qhov wavelength ntawm ultrasound yog dab tsi?
Ultrasound yog txhais los ntawm American National Standards Institute li "suab ntawm frequencies ntau dua 20 kHz". Hauv huab cua ntawm atmospheric siab, ultrasonic tsis muaj wavelengths ntawm 1.9 cm los yog tsawg dua.
Ib sab saum toj no, tus qauv rau wavelength yog dab tsi? Wavelength tuaj yeem suav nrog cov qauv hauv qab no: wavelength = yoj tshaj tawm / zaus . Wavelength feem ntau yog qhia nyob rau hauv units ntawm meters. Lub cim rau wavelength yog Greek lambda λ, yog li λ = v / f.
Ntawm no, koj yuav nrhiav tau lub wavelength ntawm lub yoj ultrasound li cas?
Cov zaus siv hauv ultrasonic Kev kuaj mob yog nyob rau hauv thaj tsam ntawm 1 txog 10 MHz. Lub suab nrawm nthwv dej nyob rau hauv cov ntaub so ntswg ntawm tib neeg lub cev qhov nruab nrab ntawm 1540 m / s (ze rau qhov ntawd rau dej). Yog li, cov wavelength ntawm 1 MHz yoj λ = v/f = 1540/1∙106 = 1.5∙10–3 m = 1.5 mm.
Yuav ua li cas ultrasound zaus xam?
Lub sij hawm ntawm ultrasound yog txiav txim los ntawm lub hauv paus thiab tsis tuaj yeem hloov los ntawm tus sonographer. Ntau zaus yog qhov hloov pauv ntawm lub sijhawm thiab txhais los ntawm ntau qhov xwm txheej uas tshwm sim hauv ib lub sijhawm. Cov units ntawm zaus yog 1/sec los yog Hertz (Hz). Txij li thaum f = 1/P, nws kuj tau txiav txim los ntawm qhov chaw thiab hloov tsis tau.
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