What Does Transducer Mean?
A transducer is an electronic device that is configured to convert energy from one form to another. Transducers may be used to monitor corrosion in metal applications via the examination of the electrochemical energy or differences in the structure (e.g., holes, wall loss) present in the material being inspected.
Corrosionpedia Explains Transducer
Examples of transducers include microphones, thermometers, pressure sensors and antennas.
Several types of transducers exist. However, the most common type used for industrial corrosion monitoring is the dual-element type. These transducers are often used in the pipeline industry to perform preventative corrosion maintenance on pipeline surfaces with the intention of preventing leaks or cracks. In this case, dual element transducers work by measuring the metal's thickness along the pipeline's length. Transducers are also used to inspect other metallic objects such as process vessels and tanks.
Irregular surface thicknesses are frequently present in pipeline applications. The transducer functions by reading the round trip time of the ultrasonic returns of a sound pulse in the pipeline's material. Because solid metal has an acoustic impedance different from that of gasses, liquids or corrosion byproducts such as rust, the sound pulse will reflect a signal that is characteristically different relative to the material being inspected. Therefore, rust will return a different reading than metal.
The test instrument is programmed with the value of the velocity of sound in the pipeline's material. It then computes the wall thickness from the simple formula for distance given the velocity and time of travel.