DF100

Patented Deep Focus Transducer

The transducer in the DeepFocus Acoustic Microscope is different. Through a unique combination of piezoelectric materials, micron-thin coatings, acoustic lenses and geometry, a highly focused, elongated, small-diameter sound beam is produced with over 60 times greater depth of field than others previously available. More like the sonic equivalent of an optical laser beam, the sound beam generated by the DF100 transducer remains powerfully focused along a small diameter straight path rather than spreading out or arriving at a point focus as with conventional transducers. It has a 0.25" depth of field in aluminum and 0.006" to 0.008" beam diameter.

Most current ultrasonic transducer technologies have a limited depth of field of approximately 0.004 in. of aluminum, needing greater than 60 test-passes with the microscope refocused each time to inspect and characterize 0.250 in. of material. The DF100’s depth of field in aluminum is 0.250 in. The increased depth of field allows characterization on the same amount of material in one test pass – a x60 increase in productivity, that’s technology with value – a value of sixty fold productivity increase!

Lower Frequency deep focus transducers now available
DF20 (20 MHz 2.0" FL) & DF05 (5 MHz, 0.5" FL)

Feature DF100 Other DF100 Advantages
Depth of Field .25" in Aluminum 0.004" in Aluminum Over 60 times greater depth of field
Integrated P/R Yes No Has extremely fast acoustic wave generation rise and fall times. Cable-less design reduces undesirable artifacts, noise and reflections
Electrical Connections SMB Micro-Dot SMB can operate up to 4 GHz
Size of Unit Compact & lightweight design Larger, bulkier designs with separate P/R 5.5" long and 1" in diameter
Cost Low High Less expensive than other ultrasonic immersion Transducer/P-R units

Improvements over competitive products and technologies

Acoustic microscopes are widely used for nondestructive testing and material characterization. Currently, available focused transducers used in most acoustic microscopes have several drawbacks including: limited depth of field; the requirement for hardware and/or software compensation to maintain signal quality over a varying "water path" distance; pulser-receivers that cause signal amplitude loss and unwanted reflections. TheDF100 Acoustic Microscope Transducer with integrated pulser-receiver is a novel design that improves upon similar products in the following ways:

1. FOCUSED DEPTH OF FIELD IS 60 TIMES GREATER THAN ANY OTHER ACOUSTIC MICROSCOPE
Depth of field is the distance over which an acoustic transducer remains in focus. Acoustic microscopes are focused in a manner similar to a standard camera—objects within a certain distance range are in focus, while objects outside that range (either closer or farther away) are out of focus. Current acoustic microscope transducer technologies have a depth of field of only 0.004 inches in aluminum. The DF100 Acoustic Microscope Transducer is the only commercially available instrument that keeps objects in focus within a 0.25-inch range in aluminum, and that means the new technology can produce clear images of sections that are over 60 times thicker than possible with current technology. This is of tremendous importance when you are looking for indications of flaws or cracks within a sample or are inspecting a sample with an irregular surface. The greatly increased depth of field possible with the DeepFocus Acoustic Microscope Transducer allows inspection and characterization of materials in a single pass, eliminating the need for tens of additional passes with the microscope refocused each time to image the material at different depths.
2. NARROW ACOUSTIC BEAM DIAMETER PROVIDES OPTIMAL IMAGE QUALITY
With an acoustic beam diameter of 0.006" - 0.008", the DF100 Acoustic Microscope Transducer is able to characterize material dimensions less than 0.005-inches deep and 0.005-inches in diameter. Larger beam diameter generally is equated with less sensitivity and resolution. However, when paired with its far greater depth of field and high signal-to-noise ratio, this combination of properties makes the DeepFocus Acoustic Microscope Transducer able to produce optimal image quality for faster, less costly characterizations.
3. HIGHER FREQUENCY TRANSDUCER FOR GREATER CLARITY
The higher the frequency response of an ultrasonic transducer, the smaller the details that can be resolved. The DF100 transducer operates at 108 MHz (reflected signal at 19 micro-seconds measures 42 MHz with water attenuation)—well above most conventional focused transducers—and is the only technology that combines a greatly extended depth of field with the ability to resolve small details to produce highly focused, information-rich images.
4. INTEGRATED PULSER-RECEIVER DOUBLES MICROSCOPE'S SENSITIVITY AND RESOLUTION
An ultrasonic transducer is made up of an active element, such as a piezoelectric or single-crystal material, which generates an ultrasonic impulse when it is energized by a pulser-receiver. Usually, the pulser-receiver is connected to the transducer by cables. At higher transducer frequencies there are significant cable problems with conventional units that degrade signals and reduce image quality. With the DF100 transducer, a unique approach is taken. The miniaturized pulser-receiver electronics are mounted on the back of the transducer. Problem-causing cable connections are replaced by a patented interface and artifact-reducing coating that integrates the pulser-receiver and the transducer in a single, slim and lightweight element. This approach eliminates cable-induced noise, high-frequency standing waves and reflections, and impedance mismatches to significantly improve signal-to-noise ratio. The integrated pulser-receiver provides for extremely fast rise and fall times of the ultrasonic signal, giving the DF100 twice the sensitivity and material image resolution of its competitors.
5. SMALLER, LIGHTER PACKAGE ONE-TENTH THE WEIGHT OF CONVENTIONAL UNITS
The DF100 transducer with integrated pulser-receiver is smaller and lighter than competitive transducers alone. The integrated package measures 5.5 inches long by 1 inch in diameter compared with bulky commercial transducers that are twice the diameter and half again as long. It weighs less than one-tenth of comparable conventional units. Unlike conventional transducers that use signal interfaces called micro dots (capable of 50 MHz operation), the DF100 transducer has SMB connections for operations up to 4 GHz.
6. DESIGN STREAMLINES APPLICATIONS, REDUCING COMPLEXITY AND COST
Existing commercial transducers are physically large, heavy and focused. For many applications, these attributes require that the transducers be mounted in complex, servo-driven, multi-axis rigs to track the front surface of sample objects under inspection. In addition, transducer failure rates are high, adding to the cost of inspections. For the first time, the lightweight DF100 transducer--with its exceptional depth of field--keeps surface and near-surface indications in sharp focus without complex and expensive servo tracking mechanisms. And, because of its over 60 times greater depth of field, the DF100 Acoustic Microscope Transducer gathers all the required image data with far fewer scan passes than are necessary with focused transducer acoustics, saving significant time and money.