DIN SPEC 91343:2017-04

This DIN SPEC has been drawn up by a temporary body ('Workshop') in accordance with the PAS procedure. This DIN SPEC has been developed and adopted by the authors named in the Foreword. This DIN SPEC describes a process for the characterization of atomized coating materials, like paint sprays or, more specifically, drops or wetted particles forming a paint spray. For this purpose, guidelines for the size measurement of spherical drops or nearly spherical drops have been defined. In such cases, the drop size is solely defined by the diameter. This DIN SPEC includes requirements about the necessary spatial resolution of the employed technique. Furthermore, guidelines for the acquisition of drop velocities and the related mass flux densities are provided. Beyond that, recommendations for the acceptable uncertainty of the measurement results are given. This DIN SPEC is valid for applications, where the drop diameters are in the range of approximately 5 Micrometer to 500 Micrometer. In order to cover the most common paint spray applications, spray processes in explosive atmospheres, with high voltage applications and PWIS-free (free of paint-wetting impairment substances) are included. Guidelines have been defined for the detection of outliers, i.e. drops whose diameters or velocities strongly deviate from mean or characteristic values of the overall spray.