Paint manufacturers are interested in the reflectivity of their products. This characteristic involves properties in both the visible region where color is important as well as extending into the Near Infrared (NIR) region where the properties of the paint with respect to solar radiation are important. In particular, the most important aspect is the degree of reflectivity. The paint may be designed to retain heat, in which case a low total solar reflectance (TSR) may be required. Alternatively, a high total solar reflectance may be desirable if the purpose of the paint is to prevent the treated surface from heating up.
The total solar reflectance calculation requires taking the raw reflectance data and applying solar weighting factors for each wavelength collected. These factors and calculations are contained within the respective norms (e.g., ASTM® G 173). It would be possible to perform these calculations by taking the raw data and using a spreadsheet, but this is tedious – particularly if the number of samples is large – and less convenient in a QC environment where an instant result is more convenient.
Learn how to accurately make these measurements using the PerkinElmer LAMBDA 1050+ UV/Vis/NIR spectrophotometer.