In the context of bulk sampling, "volume" usually refers to the volume of the individual sample. This volume is important to ensure that the sample is representative of the entire bulk material.
The exact size of the sample volume may depend on various factors, including the type of bulk material, the specific properties to be tested, and the exact sampling method used.
However, in some cases, the "volume" can also indicate the total volume of bulk material to be tested or analyzed. This could be relevant if the amount of material needed to obtain a representative sample depends on the overall size of the bulk material.
It is important to note that volume and mass are not always directly related to each other, especially in bulk materials, where packing density can vary. That is why it is often necessary to consider both the volume and mass of the sample in order to obtain accurate and representative results.