Product Presentation The calibration plate of Jingyi Optoelectronics is made of imported PTFE material fired at high temperature, which is suitable for ultraviolet-visible-near-infrared (200-2500 nm) wide spectral spectrum, which can provide more than 98% reflectivity of the whole spectrum, and can maintain constant contrast under a wide range of light conditions, and has the characteristics of waterproof and high temperature resistance, so the calibration plate is completely suitable for experiments and field applications requiring long-term exposure to harsh environmental conditions. The highest diffuse reflectance ratio is given to the diffuse reflectance standard of any known substance.