What is "gain" in ultrasonic testing?

In ultrasonic testing, "gain" refers to the amplification of the echo signal received from the tested material. This amplification is crucial because it enhances the visibility of the echoes that are generated when ultrasonic waves interact with discontinuities or features within the material being tested.

By adjusting the gain, an operator can increase the strength of these returned signals, making it easier to detect and interpret potential flaws. An appropriately set gain level can significantly improve the signal-to-noise ratio, allowing for clearer readings and more accurate assessments of the material's integrity.

This concept is vital in ensuring that even weak echoes, which might occur due to very small discontinuities or certain material characteristics, can be amplified to a level that is effectively monitored and analyzed during testing.