When should the inspection of a test specimen for discontinuities occur?

The inspection of a test specimen for discontinuities should occur after the developer has been on the specimen for the correct amount of time. This step is crucial because the developer serves to draw out any penetrant that may be present in surface discontinuities, making them visible. Proper development time allows the penetrant to migrate out effectively, resulting in a clear and accurate inspection of any flaws on the surface of the specimen.

If the inspection were to occur before the developer was applied or before the sufficient dwell time, it could lead to missing critical indications of discontinuities, as the penetrant would not have had the opportunity to reveal defects adequately. Immediate inspection after applying penetrant would also not allow for the necessary reactions between the penetrant and developer to take place. Therefore, adhering to the correct sequence and timing in the inspection process is vital for ensuring the integrity and quality of the testing results.