What is the readout mechanism typically used when testing by the ellipse method?

The readout mechanism typically used when testing by the ellipse method is most accurately represented by the cathode ray tube (CRT). The ellipse method is a specific technique used in nondestructive testing, particularly in the evaluation of ultrasonic signals. The CRT allows for the display of signals on an oscilloscope, providing a visual representation of the ultrasonic waves as they interact with the material being tested. This visual feedback is crucial for interpreting the size and shape of the response signal, which directly correlates to the material's characteristics.

In this method, the graphical representation aids in identifying flaws and irregularities since the ellipse formed on the screen can show the amplitude and time characteristics of the received echo signals. This capability makes CRTs particularly effective for dynamic signal analysis in context of the ellipse method. While meters and strip-chart recorders can also be used in various forms of testing, they do not provide the same level of detailed and immediate graphical feedback needed for the ellipse method analysis. This visual impact is vital in making accurate assessments during the testing process.