Question

100-mesh screen means

• A. 100 little square openings per one linear cm of screen
• B. 100 little square openings per one linear mm of screen
• C. 100 little square openings per one linear inch of screen
• D. 100 little square openings per one linear feet of screen

Hint:

Mesh size (e.g., 100-mesh) refers to the number of openings per linear inch in standard sieve series, used to classify particle sizes.

Answer 1

The Correct Option is C

Step 1: Understand the meaning of "mesh" in screening. 
In engineering and particle sizing, a "mesh" number refers to the number of openings per linear unit of a screen. The mesh size determines the size of particles that can pass through the screen:
A 100-mesh screen means there are 100 openings per linear unit.
The standard unit for mesh size in the Tyler or U.S. Standard Sieve Series (commonly used in engineering) is per linear inch.
Step 2: Determine the correct unit for mesh size. 
In the U.S. Standard Sieve Series, a 100-mesh screen has 100 openings per linear inch. This means there are 100 wires (or divisions) per inch, creating 100 little square openings along one inch of the screen.
The actual size of each opening depends on the wire thickness, but the mesh number refers to the number of openings, not the size of the holes.
For a 100-mesh screen, the opening size is approximately 0.0059 inches (149 microns), but the definition of "100-mesh" is specifically about the number of openings per inch. 
Step 3: Evaluate the options. 
(1) 100 little square openings per one linear cm: Incorrect, as mesh size is typically defined per inch, not per centimeter. Incorrect.
(2) 100 little square openings per one linear mm: Incorrect, as this would be an extremely fine mesh (100 openings per mm is much smaller than per inch). Incorrect.
(3) 100 little square openings per one linear inch: Correct, as this is the standard definition of a 100-mesh screen in the U.S. Standard Sieve Series. Correct.
(4) 100 little square openings per one linear feet: Incorrect, as this would correspond to a much coarser screen (only 100 openings per foot). Incorrect. 
Step 4: Select the correct answer. 
A 100-mesh screen means 100 little square openings per one linear inch of screen, matching option (3).