KROHNE OPTISENS OAM 2080 EN - Manual (Page 38)

7
TECHNICAL DATA
38
OPTISENS OAM 2080
www.krohne.com 08/2010 - MA OPTISENS OAM 2080 R01 en
Technical data
7.1 Measuring principle
The sensor is let down into the clarifier or thickener and measures the suspended solids
concentration. While it descends, it transmits the data via a communication cable to the MAC 080
converter. By submersing the sensor into the liquid, you are able to obtain reliable suspended
solids readings and avoid problems from foam and fluff layers in the clarifier or thickener.
The sensor measures transmitted light through the liquid. The measuring principle is based on
the suspended particles ability to absorb and reflect NIR (Near Infra-red) light. The light source
is a light emitting diode that pulses and emits monochromatic light with a wavelength of 880 nm
(see drawing below).
The detected measuring signal is inversely logarithmical proportional to the concentration of
suspended solids. Signal treatment or linearization is done within the converter. In addition, the
temperature is measured to be used for temperature compensation of the measured value.
INFORMATION!
The built-in temperature measurement is not a precision measurement, but shall be seen as an
indication.
Figure 7-1: Cross-section of measuring gap
1 Measuring gap
2 Light source (NIR-LED)
3 Monochromatic light beam
4 Detector
1
2 3 4
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