DIN EN ISO 7027-1:2016-11

This part of ISO 7027 specifies two quantitative methods using optical turbidemeters or nephelometers for the determination of turbidity of water. a) measurement of diffuse radiation, applicable to water of low turbidity (for example drinking water); b) measurement of the attenuation of a radiant flux, more applicable to highly turbid waters (for example waste waters or other cloudy waters).