I.Kev Taw Qhia Khoom:
Cov khoom muaj ib lub hauv paus qauv thiab kaum qhov sib txawv ntawm cov lus qhia ntawm lub phaj nruab nrab, haum rau (0.1 ~ 0.58) hli tuab ntawm cov qauv, tag nrho ntawm 10 cov lus qhia, nrog rau cov phaj nruab nrab sib txawv, tuaj yeem hloov kho rau cov qauv tuab sib txawv. Siv dav hauv kev ua ntawv, ntim khoom thiab kev saib xyuas zoo ntawm cov khoom thiab cov chaw haujlwm. Nws yog ib qho cuab yeej tshwj xeeb rau kev sim lub zog ntawm daim ntawv thiab daim ntawv cardboard.
u No.1 0.100-0.140 hli
u No.2 0.141-0.170 hli
u No.3 0.171-0.200 hli
u No.4 0.201-0.230 hli
u No.5 0.231-0.280 hli
u No.6 0.281-0.320 hli
u No.7 0.321-0.370 hli
u No.8 0.371-0.420 hli
u No.9 0.421-0.500 hli
u No.10 0.501-0.580 hli