Tests of this type would allow evaluation of performance under conditions that include aged or faded paint, dark colors, and surface contaminants such as grease or dirt stains. Tests also need to be performed under typical field conditions to determine minimum lighting requirements. The degree of cleanliness of a steel surface prior to paint application is critical to the durability of the paint. This quality in the maintenance painting progress is frequently not maintained. A means of objectively evaluating the blasted surface prior to painting would be a valuable aid in improving the quality control of the process.
Current practice makes use of visual degree of cleanliness standard.
Ultimate responsibility lies with the inspectors and is critically dependent on their skills and dedication. If a paint failure occurs, there is no traceable data other than what has been documented by the inspector. A stored digital image should be capable of providing a quantitative real-time and permanent record of the surface condition. The simple monochrome techniques described previously may have differentiation problems associated with the subtleties of the cleaned surface. A technique based on color measurement would be more applicable.