Quality control duplicates are primarily used to measure what aspect of testing?

Quality control duplicates are primarily used to measure the precision of testing in radon measurement. Precision refers to the degree of consistency or reproducibility of measurements when the same test is conducted multiple times under the same conditions. By using duplicates, testers can compare the results obtained from two separate analyses of the same sample. If the results are very close to each other, it indicates high precision, meaning the measurement process is reliable and that random errors are minimal.

In practice, a high degree of precision is crucial for establishing confidence in the measurement results, particularly in situations where even small variations in radon levels can have significant health implications. The use of duplicates helps identify any variability in the measurement process itself rather than changes in the actual radon concentration.

In contrast, accuracy pertains to how close a measurement is to the true value, bias reflects systematic errors rather than random errors, and interference involves factors that might affect the measurement outcomes adversely. Each of these is important in the context of radon measurement but quality control duplicates are specifically aimed at assessing precision.