This can now all be achieved in just one tank. Amplitude Modulation Multiple Frequencies Amplitude modulation is achieved in essentially two ways: One is to smooth-ly vary the amplitude output, or waveform, of a
generator. The other method is to introduce periodic times during ultrasonic cleaning when the
generator output is brought to zero. Waveform types include sine wave, square wave, and quarter sine wave. Quarter sine wave modulation has the largest peak power-to-average power ratio and is best suited for hard-to-
cavitate fluids. Square wave modulation has the smallest peak power-to-
average power ratio and is best for soft substrates or parts susceptible to cavitation erosion. We offer all three within our total product line. The multiSONIK, however, features sine wave modulation which is best suited for the majority of precision cleaning applications. multiSONIK is the first true, constant power, four frequency
generator. When matched to our unique universal transducer, this device offers the process engineer a new degree of freedom through the ability to select cavitation event size. Since the smallest structure you can affect is determined by the minimum size of the bubble, your cleaning results are optimized when your process includes lower frequencies for removing larger particles, and higher frequencies for removing sub-micron particles. In this scenario there is no fixed frequency at which the power pulses are supplied to the liquid and therefore, no repetitive single frequency to excite the part being cleaned into resonance. This modulation eliminates the pos-
sibility of a part being excited into a damaging resonance at a frequency of two times the sweep rate. Unlike the competition, our universal transducer is designed for a broad bandwidth and thus avoids abrupt transfers of power to the tank.Yet another innovation is the repetitive, monotonical sweeping of the fre-quency from a high frequency to a lower frequency. This causes an ever-
expanding wavelength in the tank which is repeated each sweep cycle. This results in a net upward force on contamination in the liquid. For bottom mounted transducers on a tank with overflow weirs, this extra upward force helps the system purge itself of contamination.
multiSONIK™ 2 - 22616 Glossary
Frequency Modulation The time dependence of the frequency out-
put of a
generator. One of the methods by which the cleaning activity in a tank can be affected. SWEEP The variation, within some bandwidth, of the oper-
ating frequency about the res-
onant frequency. Pioneered by Blackstone~NEY Ultrasonics' engineers, now an industry standard. dualSWEEP The variation, within some bandwidth, of the sweep rate about the opti-
mum sweep rate. Exclusive Blackstone~NEY technology designed to prevent part reso-
nance and thus damage. Duty Cycle The percent of the time during an ultrasonic cleaning cycle when the
generator output is turned on. This function enhances cleaning by facilitating the degas-
sing of a fluid, and is varied by the multiSONIK’s power control. Waveform The time dependence of the magnitude of the output of an ultrasonic
generator. This is often quantified by stating the peak power-to-average power ratio. Amplitude Modulation The time dependence of the output ampli-
tude of an ultrasonic
generator. This is another method by which the cleaning activity in a tank can be affected. upSWEEP A modification of traditional sweep such that the sound in a tank is sweeping only from high frequency to low. This exclusive technol-
ogy yields an ever increasing wavelength in the tank to bring contaminants to the surface and over the weir.
40 kHz 72 kHz 104 kHz 170 kHz The science of multiple frequenciesAs the frequency of insonation increases, the radius, and thus the energy, of each cavitation event decreases. The larger radius characteristic of lower frequencies creates a much more aggressive cleaning action, while the smaller radii bubbles of the higher frequencies are gentle and safe for long immersion times and sub-
micron particle removal.
