horiba U-51, Инструкция по эксплуатации

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6 Reference
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6.9 Turbidity (TURB) measurement
6.9.1 Principle of turbidity measurement
U-52 and U-53 sensors measure turbidity using the Transmitting and Scattering Method. U-52
sensors use a pulse light LED (infra-red emitting diode) as a light source, and detect scattered
light from a 30

angle off center. U-53 sensors use a tungsten lamp as a light source and
detect scattered light from a 90

angle. Both models display turbidity as a ratio of scattered
light to transmitted light to reduce the affect of the color of the sample. The U-53 method
conforms to EPA Method 180.1, and employs wipers to reduce the affect of air bubbles.
U-54 uses a pulse light LED (infra-red diode) as a light source, and detect scattered light from
a 90

angle. The U-54 method conforms to EN ISO 7027.
Fig. 5 U-52 turbidity sensor
Fig. 6 U-53 turbidity sensor
Fig. 7 U-54 turbidity sensor
6.9.2 Standard solution
U-50 series can perform calibration using formazin (NTU) or kaolin standard solutions as a
turbidity standard solution. However, units for the solution used for calibration should be
displayed in measurements. Do not use more than 400 mg/L of kaolin standard solution
because it increases precipitation speed, resulting in measurement error.
Transmitted
LED
light detector
Scattered
light detector
Light source
Transmitted
light detector
Scattered
light detector
Light source
Tungsten lamp
Scattered
light detector
Light source
LED