Measurement Principles - Seko K500 TB Manuel D'installation

It is powered by the mains electrical system (100 ÷ 240 Vac/dc 50-60 Hz), with L7W consumption,
through a switching Power Supply
This device has been designed for the ON-LINE analysis of the Turbidity / suspended solids
conditions in various applications:
• Biological oxidation systems
• Industrial wastewater drainage and treatment
• Fish farming
• Primary or drinking water systems
Figure 1 – Wall-mounted Turbidity / suspended solids analyser control unit
2.1

MEASUREMENT PRINCIPLES

Scattering:
Turbidity is intended as the portion of a scattered light beam that is deflected from its natural path
due to impact with denser particles within the medium (i.e. solid particles).
The measurement is performed using 90° light scattering, as prescribed by the ISO 7027 / EN 27027
standard.
The measurement method is based on the Tyndall effect.
The turbidity of the medium is determined by the amount of "scattered" light. The transmitted beam
of infrared light is scattered by the particles present within the medium.
The scattered beams of light are detected and processed by photo-receivers positioned at a 90° angle
with respect to the transmitted light beam's guide.
The signals resulting from the scattered light are then converted into frequency signals.
These frequency signals are associated with corresponding turbidity and solid concentration values
and are displayed as such.
90° light scattering measurement principle
I0 = Intensity of the transmitted light
IS = Intensity of the scattered light
A = Geometric factor
C = Molar concentration
f(α)= Angular correlation
0000137221
I = I . A . C . f(α)
s 0
Rev. 3.1
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