What must be confirmed about the piping systems before a foam solution concentration test?

Before conducting a foam solution concentration test, it is essential that the piping systems have been flushed. Flushing removes any residual foam or contaminants from previous uses, ensuring that the test results accurately reflect the performance of the foam solution being evaluated. Contaminants or leftover material could alter the concentration of the foam solution, leading to misleading test results.

Confirming that the piping is properly flushed helps guarantee that the sample tested is solely comprised of the new foam solution mixed with water in the intended concentration. This practice is crucial for maintaining the integrity of the test and ensuring the reliability of the findings, which ultimately affects the effectiveness of the firefighting efforts.

The other options focus on different aspects of readiness or maintenance of the equipment but do not address the critical need for the systems to be free from previous mixtures. For example, while inspecting for leaks is an important part of maintaining the equipment, it does not directly impact the test results related to foam concentration.