What is a technique used for leak detection that involves a dye?

Dye tracer leak testing is a recognized technique used for detecting leaks in various systems, including piping and tanks. This method involves introducing a dye into the system and observing for any signs of the dye escaping, which indicates the location of the leak.

The dye used in this method is typically a fluorescent or a vivid color that stands out against the background, making it easy to spot even small leaks. This technique is particularly useful in situations where a visual inspection is not feasible or when other methods may not effectively identify small or hidden leaks.

In contrast, the bubble test involves applying a soapy solution to the surface of a system and watching for bubbles that would form where air is escaping. While effective for some applications, it does not provide the same level of specificity as dye tracer methods.

Pneumatic testing uses air or gas to pressurize a system and checks for leaks by monitoring pressure changes, while hydraulic testing involves filling a system with liquid and observing for drops in pressure. Both of these methods may be used in various contexts but do not utilize a dye to identify leaks, making dye tracer leak testing the most suitable answer in this scenario.