MSU Extension Irrigation

The purpose of this Standard is to define a method for characterizing the uniformity of water distribution of sprinkler packages installed on center pivots and lateral move irrigation machines. This test produces data to be used in computing the coefficient of uniformity, which can assist in system design and/or selection, and can be used to quantify certain aspects of system performance in the field. The coefficient of uniformity is only one factor in evaluating total system performance. Application rates, runoff, wind, amount of water applied, pump performance, and overall system management can greatly affect the total performance of irrigation systems.

This Standard specifies a method for measuring water application depths in the field and calculating a coefficient of uniformity from the data. The Standard covers evaluation of water distribution from center pivots and lateral move irrigation machines equipped with sprinklers or spray devices. The Standard does not apply to systems in which the water application device is less than 1.5 m above the soil surface, or in which the water distribution from adjacent devices does not overlap.

Developed jointly by The Irrigation Association and the ASAE Sprinkler Irrigation Committee; approved by the ASAE Soil and Water Division Standards Committee; adopted by ASAE June 1983; reconfirmed December 1988; approved as an American National Standard May 1989; revised editorially June 1989; reconfirmed December 1989, December 1990, December 1991; reaffirmed by ANSI September 1992; reaffirmed by ASAE December 1992, December 1993, December 1994, December 1995; revised June 1996; revision approved by ANSI October 1997; revised editorially September 1998; reaffirmed by ASAE for one year January 2001; reaffirmed by ANSI March 2001; reaffirmed for five years December 2001.