Understanding Transducers in Ultrasonic Testing: Types and Functions

A transducer is an electrical device that converts one form of energy into another. In the context of ultrasonic testing, a transducer is a device that converts electrical energy into ultrasonic waves, and vice versa.

There are two types of transducers used in ultrasonic testing:

1. Pulse-echo transducers: These transducers generate high-frequency sound waves (typically in the range of 1 to 20 MHz) and listen for the echoes that bounce back from the object being tested. They consist of a piezoelectric crystal or a magnetostrictive material that vibrates when an electrical pulse is applied to it.
2. Waveguide transducers: These transducers use a special waveguide to guide the ultrasonic waves and focus them on a specific area of the object being tested. They are typically used for imaging applications, such as ultrasonic thickness measurement and defect detection.

In both cases, the transducer converts electrical energy into ultrasonic waves, which then interact with the object being tested, and the reflected waves are converted back into electrical energy by the transducer, allowing the inspector to determine the properties of the object.