Lub ntsiab lus ntawm qhov hnyav hauv lub suab nrov ntsuas (sound level meter)
Qhov Teeb Meem Tsis Txaus Siab Sib Piv (SNR), tseem hu ua Lub Teeb Meem rau Noise Ratio lossis SNR, yog binary system
Nws hais txog qhov piv ntawm cov teeb liab muaj txiaj ntsig rau lub zog tsis muaj suab nrov. Feem ntau ntsuas. Vim hais tias lub hwj chim yog qhov ua haujlwm ntawm qhov tam sim no thiab qhov hluav taws xob, lub teeb liab-rau-suab nrov piv kuj tuaj yeem suav nrog cov nqi hluav taws xob, uas yog, qhov piv ntawm cov teeb liab theem mus rau lub suab nrov, tab sis cov qauv kev suav sib txawv me ntsis. Xam cov teeb liab-rau-nruab piv los ntawm lub zog piv: S/N=10 log Ntsuas lub teeb liab-rau-nruab nrab ntawm qhov voltage: S/N=10 log. Vim lub logarithmic kev sib raug zoo ntawm lub teeb liab-rau-nruab piv piv thiab lub zog los yog voltage, los txhim kho lub teeb liab-rau-suab nrov piv, nws yog ib qho tsim nyog yuav tsum tau nce qhov sib piv ntawm cov nqi tso tawm rau lub suab nrov. Piv txwv li, thaum lub teeb liab-rau- suab nrov piv yog 100dB, qhov tso zis voltage yog 10000 npaug ntawm lub suab nrov. Hauv hluav taws xob circuits, qhov no tsis yog ib txoj haujlwm yooj yim.
Tom qab cov ntaub ntawv qhia tshwj xeeb hauv cov khoom siv phau ntawv, feem ntau muaj lo lus A, lub ntsiab lus A-qhov hnyav, uas yog hais txog qhov hnyav ntawm tus nqi raws li qee cov cai. Raws li tib neeg pob ntseg yog rhiab heev rau nruab nrab zaus khoom, yog hais tias lub teeb liab-rau-suab nrov piv ntawm ib tug amplifier nyob rau hauv nruab nrab zaus band yog loj txaus, txawm tias lub teeb liab-rau-suab nrov piv yog me ntsis qis dua qhov qis thiab siab. zaus bands, nws tsis yog ib qho yooj yim rau tib neeg pob ntseg mus ntes. Nws tuaj yeem pom tau tias yog siv txoj kev ntsuas qhov hnyav los ntsuas qhov sib piv ntawm lub teeb liab-rau-lub suab nrov, nws tus nqi yuav twv yuav raug siab dua yog tias tsis siv txoj kev hnyav. Nyob rau hauv cov nqe lus ntawm qhov hnyav A, nws tus nqi kuj siab thaum tsis hnyav.
Tsis tas li ntawd, txhawm rau simulate qhov sib txawv ntawm tib neeg kev hnov lus pom ntawm ntau zaus, lub network tau teeb tsa hauv lub suab ntsuas ntsuas uas tuaj yeem simulate cov yam ntxwv ntawm tib neeg lub pob ntseg thiab kho cov teeb liab hluav taws xob kom kwv yees qhov kev hnov lus pom. Lub network no hu ua lub network hnyav. Lub suab siab ntsuas ntsuas los ntawm qhov hnyav network tsis yog lub hom phiaj lub cev muaj nuj nqis ntawm lub suab siab (hu ua linear sound pressure level), tab sis lub suab siab kho rau kev hnov lus, hu ua weighted sound level lossis suab nrov.
Feem ntau muaj peb hom kev tes hauj lwm hnyav: A, B, thiab C. A-hnyav suab theem simulates cov yam ntxwv zaus ntawm cov suab nrov qis qis qis dua 55dB rau tib neeg pob ntseg, B-hnyav suab theem simulates cov yam ntxwv zaus ntawm cov suab nrov nruab nrab. nruab nrab ntawm 55dB thiab 85dB, thiab C-weighted suab theem simulates tus yam ntxwv zaus ntawm lub suab nrov nrov. Qhov sib txawv tseem ceeb ntawm peb yog qib ntawm attenuation ntawm tsawg zaus ntawm lub suab nrov, nrog A muaj ntau attenuation, ua raws li B, thiab C muaj tsawg attenuation. Vim nws cov yam ntxwv nkhaus nyob ze rau cov khoom ntawm lub pob ntseg ntawm tib neeg lub pob ntseg, A-weighted suab theem tam sim no tau siv dav hauv kev ntsuas suab nrov thoob ntiaj teb, thaum B thiab C tau maj mam raug txiav tawm.
