This paper is the result of expenmental study on the characteristics of distribution patterns by a middle pressure type(Standard type) Sprinkler.
The distinction of this study was that it specially experimented on the Sprinkler nozzle at the main, Sub-nozzle, and attach orifices.
All of these experiments were at wind and windless codition.
The author infers from certain measurments that an important part was played by the Sub-nozzle and that it's orifice made up a triangular distribution pattern, hence we reduced the prospect of the Sprinkler development.