Which type of spectrophotometer is commonly used in coating failure investigations?

The infrared spectrophotometer is commonly used in coating failure investigations primarily because it provides valuable information about the chemical composition of materials. This instrument works by measuring the absorbance of infrared light by the sample, which helps in identifying organic compounds and polymers that may be present in the coating. By analyzing the spectral data, inspectors can determine if the coating materials have been altered or degraded and can assess compatibility with the substrate or other coatings.

In coating failure investigations, understanding the chemical makeup of failed or deteriorating coatings is crucial. The infrared spectrophotometer allows for non-destructive analysis, making it an effective tool for identifying the root causes of failure without damaging the materials being tested. This ability to analyze the material's chemical structure aids in diagnosing issues such as improper formulation, contamination, or exposure to damaging environments.

Other options, such as the photomultiplier tube, refractometer, and digital microscope, serve different functions. For example, a photomultiplier tube is primarily used for detecting light, often in low-light applications, and does not provide the chemical information necessary for understanding coating failures. A refractometer measures the refractive index of liquids but lacks the capability to analyze solid materials like coatings effectively. A digital microscope primarily provides visual