Question

In a size reduction operation, uniformity of grind of a ground product is given by

• A. Size index
• B. Grinding modulus
• C. Uniformity index
• D. Fineness modulus

Hint:

Fineness Modulus (FM) $\rightarrow$ Average particle size.
Uniformity Index (UI) $\rightarrow$ Spread Uniformity of grind ($C:M:F$).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
The particle size distribution of milled feedstuffs and ground agricultural materials is characterized using sieve analysis to determine Fineness Modulus and Uniformity Index.
Key Formula or Approach:
\[ \text{Uniformity Index (UI)} = C : M : F \quad (C + M + F = 10) \]

Step 2: Detailed Explanation:
In ASAE ASABE Standard S319 for grain grinding:
1. Fineness Modulus (FM): An empirical number indicating the overall average fineness/coarseness of the ground product.
2. Uniformity Index (UI): Expressed as three numbers whose sum equals 10 (e.g., \(2:6:2\)), representing the proportion of Coarse (C), Medium (M), and Fine (F) particles. It directly describes the uniformity of the grind.

Step 3: Final Answer:
Hence, the uniformity of grind is given by Uniformity index, corresponding to option (C).