1 Overview
1
1
Overview
1.1
Introduction
The OPSA-150 Organic Pollutant Monitor provides continuous measurement of organic
pollutants and ultraviolet (253.7 nm) absorption in industrial wastewater, river water, and
saltwater. A typical continuous measuring device for drainage water or environmental water
cannot provide stable measurement values over long periods of use due to generation of drift
from the deteriorated light source/detector or cell contamination from the sample water. In
general, once a cell becomes contaminated, the contamination grows gradually until we know
it is too serious. To efficiently avoid contamination, continuous cleaning is most important. It is
also the key to realize long-term, stable monitoring. The proprietary rotary cell length
modulation method ensures stable monitoring. Cleaning is performed using powerful wipers to
continuously clean 2 spinning cylinders (cell windows) without obstructing the optical path,
thus eliminating read-out errors caused by contamination.
Continual correction for deterioration of the optical system, changes in the sensitivity of the
detector, and the effect of contamination on the sample cell give highly consistent and
accurate readings.
The analyzer system detects both UV and visible light (546.1 nm) absorbances
simultaneously. The turbidity correction factor (
) can be selected within the range of 0 to
9.999, according to the sample water.
When this unit is utilized for measuring organic pollutants to determine compliance with water
quality gross volume regulations, improved correlation between ultraviolet absorbance and
COD values obtained by the designated measuring method is required.
In activated sludge treated sewage water, humic acid, fulvic acid, and tannin, which are the
derivative of microbial degradation of humic substances processed by microorganisms, tend
to remain. Ultraviolet rays are absorbed by humic acid, fulvic acid and tannin acid. The
absorption of ultraviolet rays is often correlated with organic pollution affecting COD. Thus, the
correlation between the absorbance of ultraviolet light and organic pollution is improved in
many cases.
The UV absorptiometer furnishes the measured value while the visible absorptiometer
provides a reference index used to determine the turbidity correction factor (
) for more
reliable measurement and also gives independent TURB (turbidity) data.
Features
Employment of a unique system of rotary cell length modulation in the analyzer unit
intrinsically eliminates zero-drift, and a proprietary wiper-method cleaning mechanism
provides continuous cleaning, thus allowing stable measurement values over long periods
of use.
The unit features an easy-to-control monochrome graphics LCD data display (touch-
panel).
The display shows UV
，
VIS (visible light) and UV-
VIS simultaneously and can also
switch between converted the COD value and converted TURB (turbidity) displays.
Measured data can be output to the recorder as analog current output, or transferred to
the communication unit (optional) or loaded into a PC via the RS-232C port.
Measured data can be stored and read using a CompactFlash card (hereinafter referred
to as CF card).
