piezoelectric ceramic transducer

Our patented third harmonic ceramic transducers deliver outstanding ultrasonic cleaning results

When Crest Ultrasonics discovered the ability to substitute acoustically superior high-tech ceramics for metals in stacking transducers, it was perhaps the most important development in ultrasonics in the last 30 years.

High-tech ceramics transmit sound better than even the latest state-of-the-art metals used in traditional transducers.

Ceramically stacked high frequency piezoelectric transducers are designed to meet the needs of high-tech applications where the requirements are submicron cleaning. They offer superior transmission of sound at higher frequencies which results in better contaminant removal and reduced damage to sensitive parts. Both general and critical cleaning applications benefit from this advanced ultrasonic cleaning technology.

Which transducer performance would you choose?

Comparison chart: ceramic transducer at 132 kHz vs metal transducer at 40 kHz, 72 kHz, 104 kHz, and 170 kHz.

Use a ceramic ultrasonic frequency where the transducer is designed to capture direct third harmonic frequencies? Or use a metal stacked frequency (40 kHz) and pick up subharmonics at the reduced subharmonic strength?

The superiority of chart A over chart B is clearly evident.

High-tech ceramics make possible the direct stacking of high frequencies that before were only available as subharmonics of metal stacked frequencies (which derive their primary power from the weaker first harmonics).

Increased activity, eliminates damage, first harmonic STILL stronger than a metal stack!

The stacking of a piezoelectric ceramic transducer to the exact frequency results in a significantly increased level of activity and eliminates damage to sensitive parts associated with metal stacking.

Also note that even with a third harmonic direct stacking, the Crest first harmonic (40 kHz) is stronger than the competitor’s metal stacked 40 kHz.

Ceramic transmits sound at higher speeds

The acoustical speed at which sound travels through high-tech ceramics is 63% to 125% greater than aluminum, stainless steel, or titanium:

Chart showing ceramic transducer vs metal transducer (acoustical speed).

The problem with traditional metal stacked transducers is that solid metal is actually made up of strands and strands of metal, which under high magnification is actually quite porous. In the transmission of sound waves, the porosity becomes a significantly limiting factor.

High-tech ceramics like alumina oxide and silicon carbide have a composition of molecules so minute that the porosity is nearly zero. Their surfaces are so lat that they can be measured in 1,000.000 of an inch. As a result, they offer superior acoustical speed and an improved surface interface. So the stacking of an ultrasonic transducer with ceramics greatly enhances the transmission of ultrasonic energy. The near-perfect sound transmission also reduces the amount of stress involved with transmitting ultrasonic energy, resulting in increased day-to-day reliability and a much longer trouble-free life for the system in use.

The biggest advantage of a third harmonic frequency

Piezo Ceramic Crystals (PZTs) used for creating ultrasonic energy are known by their first frequencies — the traditional Crest 40 kHz PZT, for example:

piezo ceramic crystals PZT 40 kHz

40 kHz first harmonic

Expand the chart, however, and you will see an even stronger third harmonic frequency:

Note the stronger harmonic!

Note the stronger third harmonic!

Looking at the chart’s full spectrum, you will see a number of different harmonics:

You now see a total of six strong harmonics, with 40 kHz (the first harmonic) being the weakest (harmonics are counted by odd numbers only).

You now see a total of six strong harmonics, with 40 kHz (the first harmonic) being the weakest (harmonics are counted by odd numbers only).

The advantage of being able to directly stack harmonics other than the first gives the user of ceramic stacked transducers a huge advantage —  because metal stacking works ONLY off the weakest harmonics.

Learn more about how ceramic stacking works, and be sure to see our ceramic transducer FAQ page for even more information.

ORDER NOW: Call 1-800-99CREST (27378) or contact us today!

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