本文件规定了评估水域透明度的以下半定量方法: a） 使用透明测试管测量视野（适用于透明和微混浊的水），见第4条； b） 使用透明度测试盘测量上层水层的可视范围（尤其适用于地表水、洗澡水、废水，并经常用于海洋监测），见5.1； c） 潜水员在指定深度的能见度测量，见5.2。 注:ISO 7027-1中描述了使用光学浊度计或浊度计的定量方法。

This document specifies the following semi-quantitative methods for the assessment of transparency of waters: a) measurement of visual range using the transparency testing tube (applicable to transparent and slightly cloudy water), see Clause 4; b) measurement of visual range in the upper water layers using the transparency testing disc (especially applicable to surface, bathing water, waste water and often used in marine monitoring), see 5.1; c) measurement of visibility by divers in a destined depth, see 5.2. NOTE The quantitative methods using optical turbidimeters or nephelometers are described in ISO 7027-1.