These affordable and reliable manually controlled pulser-receivers provide the perfect building blocks for both conventional and high frequency applications. Each instrument is designed for superior low noise receiver response and high performance pulser control.
When used with an appropriate transducer and analog or digital oscilloscope, Panametrics pulser-receivers provide the perfect starting point for ultrasonic flaw detection, thickness gaging, materials characterization, and transducer characterization. |
Model 5072PR: 35 MHz (-3 dB) ultrasonic bandwidth and spike pulser is ideal for general testing. The impulse pulser provides optimal broadband excitation resulting in superior time domain recovery especially at higher frequencies (between 15-30 MHz).
Model 5073PR: 75 MHz (-3 dB) ultrasonic bandwidth with fast rise time spike pulser extends performance for work with 50 MHz transducers in applications that challenge limits in axial and near surface resolution.
Model 5077PR: 35 MHz (-3 dB) ultrasonic bandwidth and square wave pulser-receiver is ideal for maximizing response in scattering materials. The square wave pulser is particularly advantageous when testing with transducers of 10 MHz or lower, as adjustable pulse width optimizes pulse energy, resulting in superior signal-to-noise characteristic. |
Pulser-receivers employed with ultrasonic transducers and an analog or digital oscilloscope are the prime building blocks of any ultrasonic test system.
The pulser section produces an electrical pulse to excite a transducer that converts the electrical input to mechanical energy, creating an ultrasonic wave. In pulse-echo applications, ultrasound travels through the test material until it is reflected from an interface back to the transducer. In thru- transmission applications, the ultrasound travels through the material to a second transducer acting as a receiver.
In either case, the transducer reconverts the mechanical pulse into an electrical signal that is then amplified and conditioned by the receiver section. The resulting RF is then made available for further analysis. Since the customer chooses the waveform display and/or digitization methodology, infinite flexibility in measurement range and method may be pursued.
Square Vs. Spike Excitation
Spike excitation pulsers optimize broadband response and near surface resolution.
For applications involving the testing of thin materials with high frequency transducers where fast recovery time and broadband transducer response are important to insuring adequate time and depth resolution, Models 5072PR and 5073PR employ a spike excitation technique that produces an abrupt voltage transition followed by a recovery to the baseline. The ultra-fast rise times directly translate to broad spectral excitation resulting in wideband transducer response. It is possible to optimize transducer response by selecting pulse energy and damping values, which adjust pulse rise time, width, and voltage. In general, lower energy values and damping resistance will produce the sharpest rise times for the most efficient excitation of high frequency transducers. In fact, the 5073PR pulser electronics can achieve rise times of less than 2 ns, enabling the use of up to 50 MHz broadband transducers.
Square wave pulsers dramatically increase sensitivity while maintaining broadband performance by tuning pulse width to the resonant frequency of the transducer. Square wave excitation is especially useful in applications involving the testing of thick or highly attenuating materials with low frequency transducers, typically improving both penetration capability and signal-to-noise ratio. The Model 5077PR provides square wave excitation with a fast pulse rise and fall time. The pulse voltage and pulse width are adjusted directly to provide precise control over pulse shape. By tuning the period (pulse width) of the square wave to half that of the transducer center frequency, pulse energy to the transducer at its natural resonant frequency is increased. This can result in an increase in signal amplitude as great as 12 dB or more as compared with spike pulsers using the same voltage setting. The effect is especially pronounced with transducers of 5 MHz and lower frequency. |
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