BS EN ISO 7027-2:2019

What is ISO 7027‑2 - Water transparency assessment about?

ISO 7027 discusses water quality with a focus on turbidity or transparency. ISO 7027‑2 is the second part of the multi-series on water turbidity determination, that specifies the following semi-quantitative methods for the assessment of transparency of waters:

• Measurement of visual range using the transparency testing tube (applicable to transparent and slightly cloudy water)
• Measurement of visual range in the upper water layers using the transparency testing disc (especially applicable to surface, bathing water, wastewater and often used in marine monitoring)
• Measurement of visibility by divers in a destined depth

Who is ISO 7027‑2 - Water transparency assessment for?

ISO 7027‑2 on water transparency assessment is useful for:

• Government bodies
• Water supply and distribution networks
• Wastewater management facilities
• Geological scientists
• Test laboratories

Why should you use ISO 7027‑2 - Water transparency assessment?

Turbidity in waters is caused by the presence of undissolved and/or colloidal matter and small organisms (for example bacteria, Phyto- and zooplankton) present in the water. Turbidity changes the lighting conditions in surface waters by absorption and scattering of the light and thus influences the trophic status of these waters.

ISO 7027‑2 provides semi-quantitative methods for the assessment of transparency of waters to determine the transparency depth by Secchi disc. Reflections on the water surface can cause interferences. These are often dependent on the light and wind conditions. ISO 7027‑2 guides you to conduct turbidity / transparency tests so that you can assess the trophic levels of the water body.