wtw IFL 700 IQ, Operating Manual, Page: 7 / 44

IFL 70x IQ Overview
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Fig. 1-3 Principle of the ultrasonic measurement
Wiper (cleaning system) The IFL 700 IQ sensor has a mechanical wiper that effectively cleans
gas bubbles and dirt off the ultrasonic transducer. The wiper operates
contactless and is maintenance-free and wear-free.
1.3 Recommended fields of application
Sludge level control and monitoring in waste water treatment.
1 Transmitted ultrasonic waves
2 Echo reflected by the sludge blanket (short reflection interval)
3 Echo reflected by the bottom area (long reflection interval)
Sludge blanket level
1
3
2
Ultrasonic
transducer
Bottom
Detailed information on the subject of sludge level mea-
surement is given for example in the DWA information
sheet no. 256 "Prozessmesstechnik auf Kläranlagen, Teil
8: Messeinrichtungen zur Bestimmung des Schlammspie-
gels" (Process measuring technique at wastewater treat-
ment plants, part 8: Instrumentation for determination of the
sludge level".