When should developer solution be discarded?

The correct answer regarding when developer solution should be discarded is based on the amount of replenisher added relative to the original quantity. In radiographic testing, the developer solution plays a crucial role in ensuring the quality and reliability of the radiographic images produced. Over time and with repeated use, the developer solution becomes depleted and can lead to decreased image quality, such as insufficient contrast or fog.

When the quantity of replenisher added reaches two to three times the volume of the original developer solution, it indicates that the solution has been sufficiently used and is likely to have degraded in performance. At this point, maintaining its effectiveness for producing high-quality images becomes challenging, necessitating its disposal. This practice is essential for upholding the standards of radiographic testing and imaging quality required in nondestructive testing.

While other factors like color changes, time in use, or temperature variations may influence developer performance, they are not definitive indicators for discarding the solution as the correct answer outlines. Discarding based on replenisher volume ensures that the developer's chemical characteristics remain optimal for producing accurate and reliable radiographic results.