In which scenario is a soft brass wire brush appropriate to use?

The use of a soft brass wire brush is appropriate in the context of cleaning aggregate samples due to its characteristics that suit this specific task. Aggregate samples often contain dust, clay, and other fine materials that need to be removed for accurate testing and analysis.

The soft brass bristles provide an effective means to dislodge particles without damaging the surface of the aggregate. This ensures that the integrity of the sample is maintained, which is critical for obtaining reliable test results in mixture design and quality control. The gentle nature of the soft brass brush allows for thorough cleaning while minimizing the risk of altering the sample's physical properties.

In contrast, other scenarios such as dust removal from heavy machinery or cleaning delicate laboratory instruments would typically require different tools or methods to prevent damage or excessive wear. Scrubbing hard surfaces might be better suited to stronger brushes or cleaning tools designed to handle tougher grime or debris.