This International Standard specifies an in-field method for determining the uniformity of water distribution in the field from centre-pivot and moving lateral irrigation machines equipped with sprayer or sprinkler nozzles. The calculation of the coefficient of uniformity is also specified. This International Standard is applicable to agricultural irrigation machines for which the water application device is more than 1,5 m above the soil surface and for which the water distribution from successive devices overlaps. It is not applicable to the evaluation of centre-pivot irrigation machines equipped with various corner arm application devices.