EN ISO 6504-3 Paints and Varnishes, Determination of Covering Power, Part 3: Determination of Contrast Ratio of Light Colored Paints at Constant Spread Rate

EUROLAB laboratory provides testing and compliance services within the scope of EN ISO 6504-3 standard. EN ISO 6504-3 describes the methods for determining the opacity (by contrast ratio measurement) given by white or light colored paint films with a tristimulus value greater than 20 applied to black and white at a spreading rate of 2 m25/l.

Further collaboration has shown that higher reproducibility is achieved with films spread on polyester foil than with films spread on a black and white painting, but the latter technique is simpler to operate. This part of ISO 6504 provides both of these options.

An absolute method for determining opacity is required, as different operators using the same pull-down device will result in paint films that differ significantly in thickness. Collaborative work between groups of experts from several countries has shown that reproducible results can be obtained by determining the contrast ratio corresponding to a strictly constant diffusion ratio by interpolation between two or more measured film thickness measurements.

The spread rate (wet film thickness) selected in this part of EN ISO 6504 is considered average for brushing a free-flowing paint onto a smooth, non-porous surface. However, for certain types of paints normally used in other film thickness ranges, such as industrial enamels and printing inks, interested parties may agree on another spread rate.

EUROLAB assists manufacturers with EN ISO 6504-3 test compliance. Our test experts, with their professional working mission and principles, provide you, our manufacturers and suppliers, the best service and controlled testing process in our laboratories. Thanks to these services, businesses receive more effective, high-performance and quality testing services and provide safe, fast and uninterrupted service to their customers.