What does the term "gain" refer to in ultrasonic testing?

In the context of ultrasonic testing, "gain" specifically refers to the amplification of the received signal. This amplification is crucial because the signals that bounce back from materials can vary significantly in strength based on factors like the size, type, and orientation of the defects present, as well as the material’s properties. By adjusting the gain, an operator can enhance the visibility of these signals on the display, making it easier to detect and assess potential flaws.

This adjustment is important for ensuring that the ultrasonic testing equipment can effectively differentiate between noise and valid signals, leading to accurate and reliable testing results. Proper gain settings can help in revealing smaller defects that would otherwise be missed if the signal were too weak to be detected clearly. In summary, gain is all about enhancing the received ultrasound signal for better interpretation of test results.