Abstract: Material fringe canstant of photoelastic coating needs to be calibrated when stress or strain is measured with photoelastic material. Photoelastic coating is flexible and inconvenience to calibrate by the method of standard disk, to solve the problem,a calibration way is applied with uniform beam. The material fringe constant of epoxy phtotoelastic coating is calibrated conveniently, and uncertainty of calibration result is analyzed.

Key words: Photoelastic coating, Material fringe constant, Uncertainty of measurement