This document specifies a test method for the determination of the self-cleaning performance of sheet-form materials that contain an indoor-light-active photocatalyst or have indoor-light-active photocatalytic films on the surface, under indoor lighting environment.

This method is used to measure the change of water contact angle under indoor lighting environment, which is one of the indices reflecting the self-cleaning performance of semiconducting photocatalytic materials.

This document is not applicable to permeable materials on which water droplets cannot hold and rough materials which obscure water droplets. This document is not applicable to materials of which the changes in the water contact angle due to decomposition of adhered organic matter cannot be evaluated because even if the surface is clean, the water contact angle is remarkably large or the water contact angle cannot be sufficiently increased by attaching organic matter to the surface.