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Turbidity, Particle Concentration, and UV Absorption – 3 important Parameters for Your Water Quality


Turbidity is caused in water by mineral or organic solid particles. Studies have shown that there is a clear correlation between turbidity and the number of bacteria in a water sample. The dangers posed by these germs are made even worse by the fact that they can cling to solid particles and thus survive disinfection with chlorine, chlorine dioxide, UV irradiation or ozone. For these reasons, new guidelines call for limits below 0.2 FNU and continuous monitoring of turbidity in drinking water treatment.
Products: AquaScat WTM | AquaScat P

Particle Concentration

Although turbidity measurement is giving a trend of the amount of particles in a sample, only a particle counter can give an exact quantification and particle size distribution. Especially for membrane filtration systems and for filtration optimization particle counters are useful and necessary. The removal rate for the different grain sizes and the appearance of particles with a size of 2..5 mm can give important information on the function of the filter system.

UV Absorption

UV absorption detection at a wavelength of 254 nm can be employed to measure the total content of dissolved organic matter. Studies have shown that, for most applications, a linear correlation exists between the UV-absorption and DOC (dissolved organic carbon) values. This means that UV absorption measurement provides a continuous on-line indication for trend analysis of the DOC figure without time-consuming laboratory checks.
Products: ColorPlus in-line | ColorPlus bypass


SIGRIST provides for all these parameters solutions, which are exactly tailored to the requirements in water treatment. Specifications like the non-contact measurement or calibration with solid references increase the reliability of the measurement and reduce the maintenance to a minimum.

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René Gehri
Water, Beverages & Food, Industrial Processes
Pascal Schärer
Traffic & Environment