Qsonica Q700 Operation Manual page 10

maintain amplitude. For example, a ½ " probe at 100% amplitude w ill require approximately 5 w atts
to operate in air. The amplitude of this probe is approximately 120um. Insert the probe in w ater
and the w attage reading w ill increase to approximately 90 w atts. The w attage required to operate
the probe w ill increase as the load increases but the amplitude remains the same.
The AMPLITUDE control allow s the ultrasonic vibrations at the probe tip to be set to any desired
level. Although the degree of cavitation/ultrasonic energy required to process the sample can
readily be determined by visual observation, the amount of pow er required cannot be predetermined.
A sensing netw ork continuously monitors the output requirements, and automatically adjusts the
pow er to maintain the amplitude at the preselected level. The greater the resistance to the
movement of the probe due to higher viscosity, deeper immersion of the probe into the sample,
larger probe diameter or higher pressure, the greater the amount of pow er that w ill be delivered to
the probe. Sett ing the AMPLITUDE control to its maximum w ill not cause the maximum pow er
rating of the unit to be delivered to the sample. The maximum pow er (700 w atts) that the
Ultrasonic Processor is capable of delivering w ill only be delivered w hen the resistance to t he
movement of the probe is high enough to draw maximum w attage.
It is the intensity of cavitation that measures the effectiveness of the sonication, not the total
pow er applied to the system. Intensity is directly related to the amplitude of the radiating face of
the tip or horn. It is amplitude that must be provided, maintained, and monitored. The unit provides
controlled amplitude under varying load conditions in order to give reproducible results.
Rev. 6-12
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