What is crucial to do when ensuring that samples represent the total supply?

When ensuring that samples represent the total supply, randomly combining multiple samples is crucial because it allows for a more representative evaluation of the material being tested. By taking samples from various locations within the supply, you minimize the chances of variability that could arise from localized differences in material composition or quality.

Random sampling effectively captures the different characteristics of the overall supply. This is essential in aggregate testing because aggregates can have variations in size, shape, texture, and composition across the stockpile or production area. By pooling samples taken from diverse points, the result is a more accurate reflection of the entire batch, which leads to better and more reliable test outcomes.

Utilizing only large samples may not account for the diversity of the material if those samples come from a single location, while consistently sampling from one location risks missing variations that exist elsewhere in the supply. Sampling only from stockpiles is limiting, as it does not account for the entire production or supply chain, potentially skewing results. Therefore, combining multiple randomly taken samples is the optimal approach for obtaining a representative sample of the total supply.