Standard sieve terminology: a “200 mesh” screen corresponds to how many openings per linear inch in the U.S. standard sieve system?

Introduction:
Understanding sieve nomenclature is essential for particle size analysis and specifying screen decks. “Mesh” indicates the number of openings per unit length, not per area, in the U.S. standard sieve series.

Given Data / Assumptions:

• “200 mesh” is defined in the U.S. (Tyler/ASTM) practice.
• We are interested in the standard linear definition.

Concept / Approach:
Mesh number is the count of openings per linear inch measured from center-to-center of wires. While open area depends on wire diameter and spacing, the “mesh” designation itself is strictly linear. Therefore, “200 mesh” means 200 openings in one linear inch.

Step-by-Step Solution:
Identify definition: mesh = openings per linear inch.For 200 mesh, count is 200 per inch.Reject area-based interpretations (per inch² or per cm²).

Verification / Alternative check:
ASTM E11 and Tyler standards both define mesh as linear count; aperture size is then computed from mesh and wire diameter.

Why Other Options Are Wrong:

• Per cm or per cm²: not the U.S. standard definition.
• Per inch²: would vastly overstate the count; mesh is not area-based.
• Per mm: not standard in U.S. mesh terminology.

Common Pitfalls:
Confusing mesh with aperture size; finer mesh does not uniquely determine opening size without knowing wire diameter.

Final Answer:
Per inch (linear)