Overview
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Overview
Overview of equipment
Thank you very much for purchasing our Industrial-Use HU-200SS SS-90 MLSS Meter.
This Industrial-Use MLSS Meter consists of a HU-200SS converter and a SS-90 immersion
type detector.
With this MLSS Meter, a wide range (from 0 mg/L to 20000 mg/L) of SS contents can be
measured with excellent reproducibility using the near-infrared-radiation transmission method.
Any of the working curves of MLSS, Clay (inorganic mud) and Kaolin may be used as
standard substances of SS.
If “MLSS” is selected for an activated sludge treatment tank, “Clay” for the precipitation
treatment of construction sludge, or “Kaolin” for white mud, a concentration can be obtained
closer to an analyzed value. However, Kaolin has transmission properties that are different
from those of other components and a signal stops changing if the concentration is too high.
So measurement is limited up to 10000 mg/L.
The outputs from the converter are a concentration signal of 4 mA to 20 mA DC, contact
output of two channels, and FAIL contact output. The MLSS detector is connected by five
wires; two for communication, two for the power, and one for the ground potential. Cables may
be extended up to a length of 50 m. The sensor head (tip part) of the SS-90 detector is made
of PFA resin to which dirt does not adhere easily. A light source and detectors are attached in
a face-to-face position to the two sticks of the sensor head. The decay of transmitted light in
the gap of about 7 mm is converted to a concentration. The amount of light from a light source
is monitored by an optical detector for a reference purpose, and variations in the amount of
light are corrected by computing a ratio to a transmitted light signal. A near infrared radiation
LED light source blinks at approx. 10 Hz, and the influence of ambient light is canceled by
taking out the signal of the difference between when the light is ON and OFF.
Since the span sensitivity of the transmission method remains stable, sensitivity correction
over elapsed time is not required. In general, only zero calibration is performed at regular
intervals.
For MLSS measurement, the MLSS detector is attached to an immersion type holder or is
dropped in a pipe. A cleaner for spraying water or air on the holders is available as option. If a
cleaner is installed, the power source that can directly drive solenoid valves, etc. used for
cleaning is output from the converter.
The self-diagnosis capability checks the status of this equipment continuously and outputs an
error signal when any abnormality is found.
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Features of the Converter
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Rugged aluminum die cast
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Wide wiring space, and a terminal block for which the drop-off of screws is prevented.
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Outdoor installation type (equivalent to IP65; splash-proof construction)
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Easy-to-view display (150% zoom as compared with the conventional type)
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Front-face keys for all key operations
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Enhanced self-diagnosis capabilities
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Programmable transmission output range
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Calibration history memory
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Measurement by calling up detector-specific data without machine difference.
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Cleaning output (active voltage)
