Screen standards and mesh numbering:\nThe rule “higher mesh number → smaller aperture” applies to which screen standards?

Introduction / Context:
“Mesh” denotes the number of openings per linear inch in a screen. Across common standards, a larger mesh number indicates more openings per inch and therefore smaller apertures. While the exact aperture for a given mesh can vary slightly among standards (due to different wire diameters and series), the inverse relationship between mesh number and opening size remains consistent.

Given Data / Assumptions:

• Comparison among British, German (DIN), and American (ASTM/Tyler) standards.
• General trend, not the exact numeric aperture values, is under discussion.

Concept / Approach:
With more openings counted per inch, each opening must be smaller to fit within the same linear measure. Therefore, a 200-mesh screen has much smaller openings than a 20-mesh screen regardless of standard. Differences among standards affect the precise mapping of mesh number to aperture size (and whether the series is based on rational or square-root-of-two progressions), but not the qualitative trend.

Step-by-Step Solution:

Verification / Alternative check:
Published tables for ASTM E11, Tyler equivalent, BS, and DIN show decreasing opening sizes as the mesh count increases.

Why Other Options Are Wrong:

• Selecting only one standard ignores that the relationship is universal across the listed systems.
• “None”: contradicts basic definition.

Common Pitfalls:
Confusing “mesh” with “micron grade”; always consult the specific standard for exact conversion, especially when wire diameter matters.

Final Answer:
All of the above standards