Sensors, transmitters,compact devices and assemblies

Turbidity measurement

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Turbidity sensors using established scattered light methods, 4-beam alternating light method and attenuation measurement

Scattered light methods The 90-degree scattered light method in accordance with ISO 7027 / EN 27027 measures turbidity values under standardized, comparable conditions mainly in the low turbidity range. The 135-degree scattered light method is optimized for the measurement of high turbidities. With both methods, the solid particles in the medium cause the incident light to scatter. The scattered light thus generated is measured using scattered light receivers. The turbidity of the medium is calculated from the amount of scattered light. 4-beam alternating light method The method is based on two lights and four detectors. Long-life light emitting diodes are employed as monochroma tic light sources. These light emitting diodes are pulsed at a frequency of several kHz so as to eliminate any effects of extraneous light. With each

light signal, two measuring signals are detected by the four detectors. Eight measuring signals in total are pro cessed in the sensor and converted to solid concentrations. The 4-beam alternating light method allows users to compensate for any fouling and aging of optical components. Attenuation measurement Attenuation measurement is also performed in accordance with ISO 7027. A light source radiates a light beam through the medium. The detector is positioned in line with the light source and detects the transmit ted light. This measuring method is suitable for medium to high turbidities.

Scattered light methods: The scattered light generated by solid particles is measured at 90° and 135°

The 4-beam alternating light method compensates fouling and aging

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Attenuation measurement: The transmitted light is measured.

1 Turbimax CUS52D potable and process water sensor Fine turbidity range with a resolution of 0.0015 FNU; scattered light measurement according to ISO 7027; easy calibration and verification with solid state reference; hygienic version for direct inline mounting

2 Turbimax CUS51D wastewa ter sensor All wastewater applications; 4-beam alternating light methods; excellent long-term stability; cleaning only - no maintenance; automatic air cleaning, if required

3 Turbimax CUS50D absorption sensor For industrial wastewater and process applica tions; light attenu ation according to ISO 7027; high level of measure ment accuracy and repeatability; robust materials for appli cation in aggressive media or seawater; optional automatic air cleaning

Benefits • Standardized measurement method • Reliable measurements • Excellent long-term stability • Portfolio suits all applications