东西仪（北京）科技有限公司
五金通金牌会员 第13年
已通过企业工商认证
公司服务热线
18910282512
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| 详 细 说 明 | ||
LEA NUMBERS® Low Contrast Test, 10MNow its easy to measure, record and detect changes in the transfer of visual information when the change only affects visual acuity at low contrast levels. Chart divsents numbers at the following contrast levels: black, 25%, 10%, 5%, 2.5%, and 1.25%. Pages are offset for easy flipping. Each chart includes recording forms and instructions. 6 pages, 3.25" x 9" (8.25 cm x 22.9 cm). |
