Tech Showcase: Choosing a Transducer
In ultrasonic testing, the transducer converts electrical pulses into sound waves while the ultrasonic test instrument generates the initial electric pulse to the transducer and electronically processes the received pulses from the transducer. The transducer is the ear of the system, with a piezoelectric element that transforms electrical pulses into high-frequency sound and vice versa. The most commonly used resonant frequencies are 1, 2.25, 5, 10 and 15 MHz, and the transducer’s resonant frequency may be between 100 kHz and 100 MHz. In addition to the frequency, damping of a transducer is key to its performance, with narrow-band transducers offering more efficiency, but moderate depth resolution. Conversely, broad-band transducers have optimum depth resolution but lower efficiency, with efficiency referring to its ability to convert electrical energy to mechanical energy and back.
Several different types of transducers are commonly used today, including contact, delay-line, dual, angle beam, immersion and multielement. Transducers can be electrical, electronic or electro-mechanical, as seen with this range of products. This technology review highlights several different types of equipment, allowing quality professionals to consider which product works best for their application.
This gage sensor uses linear glass scale technology. The main advantage of this principle is that operators can maintain high, consistent accuracy throughout its entire range. The GS-7710 produces measurements to 0.00004 inch, and throughout its 10-millimeter measuring range. Also, a dust bellow is provided for extra protection to enable accurate measurements in a harsher environment. Endurance testing shows this sensor may be used beyond 5 million strokes. The GS-7710 comes equipped with an attached six-foot signal cable that can be directly connected to an array of remote displays with various outputs. The outputs are not only compatible with PCs, but with many SPC data acquisition systems on today’s market. If operators require more than the standard 6-foot cable length, they may easily add on extension cables up to 100 feet.