contact transducer is a single element transducer, usually generating
a longitudinal wave, that is intended for direct contact with a test
piece. All contact transducers are equipped with a WC5 wear face that
offers superior wear resistance and probe life as well as providing an
excellent acoustic impedance match to most metals.
A dual element transducer consists of two
longitudinal wave crystal elements (one transmitter and one receiver)
housed in the same case and isolated from one another by an acoustic
barrier. The elements are angled slightly towards each other to bounce
a signal off the backwall of a part in a V-shaped pattern. Dual
element transducers typically offer more consistent readings on
heavily corroded parts, and can also be used in high temperature
beam transducers are single element transducers used with a wedge to
introduce longitudinal or shear wave sound into a part at a selected
angle. Angle beam transducers allow inspections in areas of a part
that cannot be accessed by the ultrasonic path of a normal incidence
contact transducer. A common use for angle beam transducers is in weld
inspection, where a weld crown blocks access to the weld zone of
interest for a standard contact transducer and where typical flaw
alignment produces stronger reflections from an angled beam.
line transducers are single element broadband contact transducers
designed specifically to incorporate a short piece of plastic or epoxy
material in front of the transducer element. Delay lines offer
improved resolution of flaws very near to the surface of a part and
allow thinner range and more accurate thickness measurements of
materials. Delay lines can be contoured to match the surface geometry
of a part and can also be used in high temperature applications.
face transducers are single element longitudinal wave transducers with
threaded case sleeves, which allow for a delay line, wear cap or
membrane. This makes them extremely versatile and able to cover a very
wide range of applications. Protected face transducers can also be
used as a direct contact transducer on lower impedance materials such
as rubber or plastic for an improved acoustic impedance match.
transducers are single element longitudinal wave transducers, whose
wear face is impedance matched to water. Immersion transducers have
sealed cases allowing them to be completely submerged under water when
used with a waterproof cable. By using water as both a couplant and
delay line, immersion transducers are ideal for use in scanning
applications where consistent coupling to the part is essential. As an
additional option, immersion transducers can also be focused to
increase the sound intensity in a specific area and decrease the spot
size of the sound beam.
frequency transducers are either delay line or focused immersion
transducers and are available in frequencies from 20 MHz to 225 MHz.
High frequency delay line transducers are capable of making thickness
measurements on materials as thin as 0.0004” (0.010 mm) (dependent on
material, transducer, surface condition, temperature and setup), while
high frequency focused immersion transducers are ideal for high
resolution imaging and flaw detection applications on thin, low
attenuation materials such as silicon microchips.