How to calibrate the standard color plate of the colorimeter?

How to calibrate the standard color plate of the colorimeter?
The colorimetric standard data attached to the standard color palette is provided by the metrological verification department. The general method of metrological verification is:

① Perform visual inspection of the standard color palette. If it is damaged or contaminated, stop using it; if it is slightly contaminated or floating dust, clean it up and perform measurement;

②The measurement should be carried out under the specified geometric conditions;

③Use a spectrophotometer specially designed for color measurement to measure the spectral reflectance of the standard plate. This kind of spectrophotometer usually has an integrating sphere accessory or several other accessories.

④The wavelength range of the first-level standard color plate is 380nm to 780nm; the wavelength range of the second-level standard color plate should not be less than 400nm to 700nm, and the wavelength error should be less than 0.5nm. The half-width of the spectral passband should be within 10nm.

⑤The instrument should use a higher-level standard white board as a reference standard, and can only be used to measure the standard color board after calibration.

⑥ After measuring the spectral reflectance of the standard color plate, calculate the tristimulus value under a certain designated standard illuminator, and then calculate the color coordinates x, y.

The verification period of standard color swatches is generally one year, but if there is an obvious surface on the surface of the standard color swatch, and the accuracy of its measurement value is doubted, it should be sent to the measurement department for verification in time.