When are condition checks for active tests performed?

The correct understanding of when condition checks for active tests are performed is that they occur at the beginning of each test. This is crucial because performing a condition check at the start ensures that the equipment used for the radon measurement is functioning properly, calibrated, and set up in accordance with the testing protocols. Conducting these checks helps to establish a reliable baseline and ensures that any data collected during the test will be valid and accurate.

If conditions were to change during the test or if the equipment were to malfunction later, it could lead to erroneous radon readings, which would compromise the integrity of the entire testing process. Therefore, establishing proper conditions before testing is essential for accurate assessments of radon levels. Regular checks throughout the testing period are important; however, they primarily focus on confirming the initial setup's integrity and readiness, which emphasizes the necessity of checks at the beginning of each test.