Table of Contents
Advertisement
probe tip remains constant. The displayed wattage readings will vary as the load
changes, however the amplitude will remain the same.
The resistance to the movement of the probe determines how much power will be
delivered to maintain amplitude. For example, a 1/2" probe at 100% amplitude will
require approximately 5 watts to operate in air. The amplitude of this probe is
approximately 100um. Insert the probe in water and the wattage reading will increase to
approximately 90 watts. The wattage required to operate the probe will increase as the
load increases but the amplitude remains the same.
The amplitude control allows 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 power
required cannot be predetermined. A sensing network continuously monitors the output
requirements, and automatically adjusts the power 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 power that will be delivered to the probe.
Setting the amplitude control to its maximum will not cause the maximum power rating of
the unit to be delivered to the sample. The maximum power (2,000 watts) that the
Ultrasonic Processor is capable of delivering will only be delivered when the resistance
to the movement of the probe is high enough to draw maximum wattage.
It is the intensity of cavitation that determines the effectiveness of the sonication, not the
total power 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.
20
Advertisement
Table of Contents
