| 摘要 |
<p>The method involves adding a tracer colorant to the substance before introducing in the fluid, whose concentration is determined and evaluated during and after the use of the working fluid. The tracer colorant is added in a predetermined quantity. A fluorescent colorant is used as tracer colorant. A fluorescent colorant, emitting different wavelengths, is added to the substance by application of a substance mixture.</p> |
