BS EN ISO 7027-2:2019

This standard BS EN ISO 7027-2:2019 Water quality. Determination of turbidity is classified in these ICS categories:

• 13.060.60 Examination of physical properties of water

This document specifies the following semi-quantitative methods for the assessment of transparency of waters:

1. measurement of visual range using the transparency testing tube (applicable to transparent and slightly cloudy water), see Clause 4;

2. 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;

3. 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.