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Design and function
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3.3 Control panel for control unit ST 30 DT
Fig. 3
Controls for ST 30 DT
1 On/off button for switching the ultrasonic bath on and off
2 Temperature scale
3 Button for setting the sonication time with time scale
4 Start/stop button for ultrasound
3.4 Function
The ultrasonic bath uses cavitation triggered by low-frequency ultrasound. Piezo-
electric oscillating systems are located on the underside of the ultrasonic oscillat-
ing tank. The ultrasound generates large pressure fluctuations in the sonication
fluid. Cavitation bubbles are formed at the pressure minima. At higher ambient
pressures around the bubbles, the bubbles collapse very quickly. Strong, localised
microstreaming then occurs on the surfaces of the treated objects. As a result
soiling is removed from the surface of the objects. Particles of dirt are lifted off
and fresh sonication fluid follows.
SONOREX ultrasonic baths use SweepTec®, a technology in which the ultrasonic
frequency varies frequently around the working frequency. The optimum working
frequency depends on the load, filling level, temperature and type of sonication
fluid. The working frequency can differ greatly from the nominal frequency.
SweepTec® creates a particularly homogenous ultrasonic field within the operat-
ing volume for continuously optimum results.
