What is the recommended technique to sample stockpiles created by loader operations?

The recommended technique to sample stockpiles created by loader operations involves inserting a shovel vertically into the stockpile and rolling it back. This method is effective because it allows for the collection of material from various depths within the pile, which helps ensure that the sample is representative of the entire stockpile rather than just a superficial layer.

Sampling only from the top layer or taking surface samples only would not provide an accurate representation of the material in the stockpile, as these methods may miss variations in quality or composition that exist deeper within the pile. Similarly, only taking samples from the center could lead to a biased sample that does not reflect the overall material quality, since this approach ignores outer areas that may have different characteristics. By using the technique of vertical insertion and rolling the shovel back, inspectors can ensure a more thorough and accurate sampling process.