Characterization of the erosive power of the suspension used within the framework of accelerated wear tests of spraying nozzles.

The study concerns the application techniques of agrochemical products and especially focuses on the wear of spraying nozzles. This one leads to a modification of the spraying characteristics and the homogeneity of distribution deteriorates. An accelerated wear process of nozzles is defined by the standard ISO 5682-1, which makes it possible to compare the wear resistance of the different nozzles available on the market. In order to accelerate the process, an erosive suspension is used in the test rig, but this suspension looses its characteristics during the utilisation time. This is the reason why a system measuring continuously the erosive power has been set up. This system is validated by different discontinuous measurement and the correlation observed have a coefficient of about 0,99. From the signal detected by the new device, two calculations have been carried out. A first one determining continuously the total wear quantity of the nozzles. A second one identifying continuously the erosive power of the suspension. On the one hand, we obtain a basis allowing to compare the wear resistance of nozzles and on the other hand, a parameter indicating the appropriate time to change the suspension.