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to be mixed effectively. Without effective mixing you cannot ensure the entire sample volume will pass
below the tip and become processed. The probe should be immersed at least 1.5 times the tip diameter.
Before processing actual samples, it is recommended to test the probe in a vessel filled with water to
observe the ultrasonic energy and the flow pattern of the liquid. During this test you can adjust the
probe’s depth until you see adequate mixing and movement of the water.
Booster Horn
A booster is a device that increases the amplitude (intensity) of a 1” or ¾” probe. For example, a 1 liter
sample can be processed twice as fast with a 1” probe and booster when compared to the 1” probe used
alone. Smaller diameter probes already offer high intensity and will crack if used with a booster. The
booster may be beneficial when processing difficult samples with volumes above 500ml.
Power vs. intensity
Power is the measure of the electrical energy that is being delivered to the convertor. It is measured in
watts and displayed on the sonicator’s screen. At the convertor, the electrical energy is transformed into
mechanical energy. It does this by exciting the piezoelectric crystals causing them to move in the
longitudinal direction within the convertor. This change from electrical into mechanical energy causes a
motion that travels through the horn/probe causing the tip to move up and down.
The distance of one movement up and down is called its amplitude. The amplitude is adjustable. Each
probe has a maximum amplitude value. For example, with a ½” diameter probe at setting 100%, the
probe will achieve an amplitude of approximately 120µm. At setting 50% the amplitude is approximately
60µm. Note this is approximate and not perfectly linear. Qsonica measures the amplitude of each probe
at 100% and these values are published in the brochure.
Amplitude and intensity have a direct relationship. If you operate at a low amplitude setting, you will
deliver low intensity sonication. If you operate at a high amplitude setting, you will have high intensity
sonication. In order to be able to reproduce results, the amplitude setting, temperature, viscosity and
volume of the sample are all parameters that need to remain consistent. The amplitude, not the power, is
most critical when trying to reproduce sonication results.
Power has a variable relationship with amplitude/intensity. For example, sonicating water requires less
wattage when compared to a viscous sample (such as honey). While sonicating both samples at the
same amplitude setting the power/wattage will differ because the viscous sample will require more watts
in order to drive the horn. The viscous sample puts a heavier load on the probe so they system must work
harder to vibrate up and down at the same amplitude setting. The honey may draw double the watts
when operated at the same amplitude as the water sample.
Small fluctuation in the wattage display during sonication is normal. Major swings in wattage (+/- 30
watts) may indicate a problem with the sample, setup or the sonicator itself.