Sprinkler Irrigation Design & Distribution Uniformity

Christiansen's Uniformity Coefficient ($CU$) for a catch-can sprinkler evaluation test with $n$ observations $X_i$ and mean $\bar{X}$ is defined as:

Options:

• (A) $CU = 100 \left( 1 - \frac{\sum |X_i - \bar{X}|}{n \bar{X}} \right)$
• (B) $CU = 100 \left( 1 - \frac{\sum (X_i - \bar{X})^2}{n \bar{X}^2} \right)$
• (C) $CU = \frac{\text{Minimum Catch}}{\bar{X}} \times 100$
• (D) $CU = 100 \left( 1 - \frac{\bar{X}}{\sum X_i} \right)$