Qhov nruab nrab transmittance ntawm looj tsom iav dub

(Ultraviolet cheeb tsam)
Qhov nruab nrab transmittance yog qhov nruab nrab transmittance ntawm ultraviolet rays nyob rau hauv lub ultraviolet spectrum ntawm lub lens, thiab tus qauv stipulates:
a) Nyob rau hauv UVA band ntawm 315nm ~ 380nm, qhov nruab nrab transmittance τSUVA yuav tsum tsawg dua los yog sib npaug rau τV;
b) Hauv UVB band ntawm 290nm ~ 315nm, nws qhov nruab nrab transmittance τSUVB yuav tsum tsawg dua 0.5τV.
Tsis tas li ntawd, nyob rau hauv lub UVB band, qhov nruab nrab kis tau tus mob piv ntawm lub teeb-xim looj tsom iav dub yuav tsum tsawg tshaj li los yog sib npaug rau 30 feem pua, thiab qhov nruab nrab kis tau tus mob piv ntawm sunshade tsom iav yuav tsum tsawg tshaj li los yog sib npaug li 5 feem pua.
Thaum cov looj tsom iav tau ua tau raws li qhov yuav tsum tau ua, nws ua tau raws li qhov tseem ceeb tshaj plaws ntawm kev tiv thaiv, uas yog, thaiv lub teeb muaj zog thaum tseem thaiv qhov sib thooj ntawm cov teeb ci ultraviolet, hnav cov looj tsom iav dub yuav tsis ua kom lub teeb ultraviolet tau txais (hnub looj tsom iav dub, yuav txo cov luminous flux rau hauv tib neeg lub qhov muag, ua rau cov neeg hnav cov menyuam kawm ntawv loj, nyob rau hauv tib yam kev mob sab nraud, yog tias cov looj tsom iav dub tsis tuaj yeem thaiv qhov sib thooj ntawm cov teeb ci ultraviolet, tib neeg lub qhov muag yuav tau txais UV ntau dua li qhov tsis muaj looj tsom iav dub). Thaum lub Kaum Ib Hlis 2006, GB10810.3 "Cov iav lo ntsiab muag thiab cov khoom lag luam ntsig txog Tshooj 3: Cov kev qhia tshwj xeeb thiab kev ntsuas", uas tau ua tiav, tau hais meej meej tias qhov siab tshaj plaws ultraviolet transmittance ntawm looj tsom iav dub yuav tsum tsis pub tshaj 5 feem pua.