Screening statements: choose the single incorrect statement after normalization of facts.

Introduction / Context:
Screen terminology often causes confusion. Standard laboratory sieves (ASTM/ISO) use woven wire cloth with square apertures and specify mesh as openings per linear inch.

Given Data / Assumptions (Repaired):

• Mesh refers to count per linear inch, not per cm.
• Standard woven wire test sieves have square openings.
• Impact crushers (hammer mills) break by impact.

Why the Correct Option Is Wrong:
Statement “Standard test screens are manufactured with circular openings” is incorrect; standard test sieves use square openings produced by orthogonal wire warp and weft. Circular perforated plates exist but are not the standard for test sieving nomenclature.

Why Other Options Are Right:
Hammer crushers: impact is the principal mechanism.Mesh number vs opening: as mesh count increases, aperture decreases.200-mesh: indeed 200 openings per linear inch.

Common Pitfalls:
Confusing “mesh per cm” with the standard US “per inch”, and assuming all industrial screens are identical to laboratory test sieves.

Final Answer:
Standard test screens are manufactured with circular openings.