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.
EN ISO 7027-2:2019 history
2019EN ISO 7027-2:2019 Water quality - Determination of turbidity - Part 2: Semiquantitative methods for the assessment of transparency of waters