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InterRanger
DPS300
Distance Calculation
To calculate the transducer to sludge distance, the sound velocity (P653) is
multiplied by the acoustic transmission to reception time period.
Distance = Sound Velocity x Time
2
The Reading Value displayed is the result of performing any additional
modification to the calculated distance (Operation P001, Units P005, Volume
Conversion, P050 to P054, Reading Value, P060 to P063.)
Sound Velocity
The velocity of sound in water is affected by its temperature. The DPS300 is
preset for operation in water at 20°C (68°F). Unless altered, the sound velocity
used for the distance calculation is 1483 m/s (4864 ft/s).
The XCT-12 transducer incorporates a temperature sensing element which
provides temperature reporting to the DPS300 for automatic compensation of
sound velocity.
Also, if the temperature varies between the transducer face and the sludge
surface, a TS-3 temperature sensor, mounted in between can be used in
combination with the transducer. Then when Temp Source, (P660) is set for
“both”, the transducer and TS-3 temperature measurements are averaged.
Scanning
When echo processing is complete, (if two clarifiers are monitored) the scanning
relay changes state to supply the transmit pulse to the transducer of the other
clarifier after the Scan Delay (P727).
Volume Calculation
The DPS300 provides a variety of volume calculation features (P050 to P055).
If the clarifier to be monitored does not match any of the 8 preset shape
calculations, a Universal Volume calculation may be used. Use the level/volume
graph or chart provided by the clarifier fabricator (or create one based on the
clarifier dimensions).
From this graph, determine which Universal Volume calculation will provide the
best results, and select the level vs. volume breakpoints to be entered (32 max.).
Generally, the more breakpoints entered, the greater the volume calculation
accuracy.