Which of the following describes the receiver-amplifier circuits in ultrasonic testing systems?

The receiver-amplifier circuits in ultrasonic testing (UT) systems are primarily responsible for modifying the electrical signals that are received from the transducer before they are displayed visually for analysis. When ultrasonic waves are transmitted into a material, the waves interact with flaws and boundaries, reflecting back to the transducer. The transducer converts these returning ultrasonic waves into electrical signals.

The receiver-amplifier circuit then processes these signals: it amplifies them to make weak echoes detectable and modifies their characteristics, such as increasing certain frequencies or filtering out noise. This modification is critical for producing a clear and informative display on the testing equipment, allowing the operator to interpret the presence and characteristics of any flaws accurately.

In contrast, while some circuits in ultrasonic systems may assist with filtering and signal processing, the specific role of modifying signals for display is what defines the primary function of the receiver-amplifier in this context. Understanding this function is essential for interpreting the results of ultrasonic testing effectively.