The weld inspection method that employs penetrameters is called:

The method that employs penetrameters is referred to as radiographic inspection. Penetrameters, also known as sensitivity gauges, are specifically used in this inspection method to assess the quality of radiographs and measure the contrast and clarity of the images produced. In radiographic inspection, X-rays or gamma rays penetrate the material being examined, and penetrameters are placed on or near the test object to ensure that the radiographic technique has sufficient sensitivity to detect flaws within the weld or base material.

The use of penetrameters helps to standardize the interpretation of radiographic images by providing a reference for the minimum detectable size of flaws, ensuring that the inspection method is both reliable and effective for assessing weld integrity. It is this ability to quantify and improve the effectiveness of radiographic inspections that distinguishes this method from others, such as magnetic particle inspection, ultrasonic inspection, and visual inspection, which utilize different principles and criteria for defect detection and analysis.