The TRZ Horn Analyzer is a high-tech device dedicated to tuning, frequency analysis, and testing of power ultrasonic transducers, horns (sonotrodes), and correlated devices. The TRZ is for these elements as an oscilloscope is for the electronics.
With the TRZ, the transducers and sonotrodes become just as measurable and adjustable as any other device.
The TRZ Horn Analyzer determines the operation frequency of the item to be tested and its impedance and current with the touch of a button. It’s quick and easy. With this quick and easily retrieved information, the user can perform the quality control of transducers, tuning of sonotrodes and ultrasonic horns, preventive and corrective maintenance of acoustic sets, and much more.
The proper frequency and impedance adjust is indispensable for all ultrasonic devices. The frequency depends mainly on dimensions (e.g.: length of the sonotrode) and the impedance of the quality of material used, assembly, and coupling of the acoustic sets’ parts. Deviations indicate the need for fine tuning, cleaning, re-gripping or re-assembly.
Advantages and Benefits
- Practicality and ease of use. No need for ultrasonic expertise.
- Allows the quality control of ultrasonic transducers reducing technical assistance.
- Makes fast and accurate manufacturing of sonotrodes possible.
- Affordable cost.
- Reduces ultrasonic equipment maintenance costs because it allows preventive maintenance.
Usage Guidelines
To operate, the TRZ Horn Analyzer requires only a power outlet of 127 or 220 VAC (50-60 Hz). After connected, simply connect the transducer to the test probe, select the type of transducer, and order the measure. The result is shown on a display with backlight and high contrast. To repeat the test, simply press the "Start" button again.
Types of Transducers and the Equipment Characteristics
The equipment has 27 pre-configured transducers, 09 of welding system, 16 of cleaning and 02 of dental scalers. Additional settings can be incorporated according to the customer's needs.
For the tuning of sonotrodes it is necessary to couple it with a transducer.
The TRZ Horn Analyzer is also suitable for the determining of the impedance of other piezoelectric devices such as sensors, accelerometers and actuators.
Features of the instrument for ranges from 5 to 100 kHz and from 50 Ω to 20 KΩ
| Parameters | Minimum | Maximum | Units (mm) |
| Frequency range: | 1 | 200 | kHz |
| Impedance range |Z|: | 0.1 | 999k | Ohms |
| Frequency accuracy: | ±0.05 | - | % |
| Impedance accuracy*: | ±3 | - | % |
| *Uncertainty values at 10 kHz for the range from 0.1 kΩ to 10kΩ purely resistive. | |||
Principle of Operation - Advanced Information
The TRZ Horn Analyzer measures the module of impedance as a function of frequency, applying a sinusoidal signal of constant amplitude and monitoring the current flowing through the device under test as a function of frequency. The signal frequency is changed in scan mode in the range of interest discretized in a certain number of points. After scanning, an algorithm of the embedded software detects the frequency of resonance and anti-resonance and their impedances.
In the case of ultrasonic transducers for cut and welding and for dental scalers, the values presented on the display correspond to the anti-resonance. For the cleaning transducers and tanks, the values corresponds to the resonance.
The frequencies are identified through an algorithm that searches the points with zero derivatives, which in turn occur at resonance (a local minimum) and at anti-resonance (a local maximum). Around these points a polynomial interpolation is performed in order to have greater accuracy than provided by the discretization. Additionally, in the case of the option cleaning tank, an algorithm of moving average is applied to smooth the curve and to obtain an average value in the region where the resonances of the various transducers of the tank occur.
TRZ Ultrasonic Horn Analyzer
The TRZ Horn Analyzer has a wide range of applications, ranging from the quality control of transducers for medical and dental applications up to sonotrodes for cutting and welding of polymeric materials.
The TRZ is also used in received equipment inspection by companies that have a large number of ultrasonic welding or cut machines, to prevent the production line stoppages due to non-compliant spare parts.
Testing and Quality Control of Transducers
The quality control of ultrasonic transducers is performed by the characterization of their frequency and their impedance of operation. To be approved, these parameters must be within acceptable ranges. For example, a transducer (otherwise called a converter) of 20 kHz for ultrasonic welding, should have a frequency of 20,500 Hz with a tolerance of ± 50 Hz, i.e, to show a frequency between 20,450 and 20,550 Hz, and an impedance of at least 30 kΩ.
Deviations indicate problems in the parts manufacturing and / or assemblage and must be meticulously evaluated to avoid future problems of low performance and technical assistance. A transducer with characteristics outside these ranges can operate, but with low performance, overheating, and reduced work life - besides the risk of damage to the generator and associated items such as sonotrodes and boosters.
When a transducer has non-compliance, it can be recovered by identifying and correcting the problem. Typical causes are dimensional deviations (frequency change) and assembly failures(impedance change).
The acceptance intervals are determined from the characterization of the average values and deviations of a pilot batch of reference transducers. When necessary, the ATCP can offer a customized consultation to assist the determination of acceptance intervals.
The ATCP offers a printer to register the test results in a self-adhesive label attachable to the item tested, and software that applies the acceptance criteria and automatically generates a PDF report of the result as optional items.
The transducers used in dental scalers and ultrasonic scalpels are other examples of transducers for which the quality control is very important.
Tuning of Sonotrodes
The sonotrodes and/or tools for ultrasonic welding and cutting are items that require a perfect tuning for the proper functioning and long work life. This is also the case of medical equipment such as scalpels and ultrasonic scissors. Tuning means adjusting the frequency of resonance.
In the case of the sonotrodes, the tuning is accomplished by adjusting its dimensions to achieve the desired frequency employing machine tools (lathe, milling, and grinding) and the TRZ Horn Analyzer. Besides the frequency, the TRZ measures another fundamental parameter for the operation, which is the electrical impedance.
Even if the sonotrode is produced with high precision and reproducibility by a CNC machine, the frequency fine tuning is always a necessity. The elastic properties of an alloy differ from batch to batch or even in a single piece, especially for those subjected to tempering process. When you remove material from a sonotrode, the shortening of its length causes a rise in frequency, however it isn't possible to add material for its frequency decreases. Therefore, the the process of manufacturing a sonotrode consists of projecting the piece and machining it with a length slightly greater than the final length, and performs the wear at the piece together with the characterization by the TRZ Horn Analyzer until frequency rises and reaches the desired value.
When necessary, the ATCP provides customized consulting of TRZ Horn Analyzer application to facilitate the establishment of the tuning process of the sonotrodes in the customer´s facilities.
Preventive Maintenance
The prolonged use of transducers, boasters, and mostly acoustic sonotrodes is ultimately accompanied by wear and tear, that can compromise the performance of ultrasonic equipment and lead to damage. With the vibration, the reduction of the grip of the ceramics and the commitment of the joint surfaces becomes a possibility.
The TRZ Horn Analyzer allows periodic testing of acoustic sets in order to correct deviations before they have irreversible consequences.
Corrective Maintenance
The TRZ facilitates the reconditioning of ultrasonic transducers that have suffered from broken ceramics and the verification of grinding or lathe processes so as to correct the surface of sonotrodes.
Developments
The applications of the power ultrasound are vast and are continually expanding.
For the development and improvement of ultrasonic products, the availability of equipment such as the TRZ Horn Analyzer is essential.
The TRZ Horn Analyzer equipped with optional software enables the frequency chracterization and impedance of operation and visualization of the curve of the transducer (module of impedance versus frequency). From the visualization of this curve it is possible to identify and remove spurious resonances, for example.
For developments and / or specific improvements, the ATCP offers the services of characterization and consulting.
Teaching Applications
Technically, the TRZ is an impedance analyzer that can be used in electrical engineering teaching labs to demonstrate the concepts related to reactive systems, resonant circuits and power factor, since it also characterizes passive components in a manner similar to an LCR bridge.