Probes are made from titanium and machined to specific sizes and shapes. When driven at their resonant frequency, they expand and contract longitudinally. This mechanical vibration is amplified and transmitted down the length of the probe. In liquid, the probe causes cavitation which constitutes the main mechanism for sample processing. Choosing the appropriate size probe is extremely important. The sample volume to be processed is directly related to the tip diameter. Probe tips will pit or erode over time and require replacement. Using an excessively worn tip can affect your results and possibly overload the generator.