Which factor must be controlled to ensure accurate sampling?

To ensure accurate sampling, it is essential to control the sampling method. This is because the sampling method dictates how representative and reliable the samples will be. An appropriate sampling method ensures that the sample accurately reflects the characteristics of the entire batch or lot being tested. This involves following standardized procedures for the extraction of samples, taking the right quantity, and avoiding contamination or bias during the process.

Timeliness, environmental impacts, and operator skills may all contribute to the overall quality of sampling, but it is the methodology that directly governs the integrity and validity of the samples collected. A well-defined and executed sampling method minimizes variability and errors, leading to more dependable data for analysis and decision-making in asphalt production.