(1) sample sampling process.
① The size and shape of the specimen should be the same as the blue wool standard because of the larger area of the sample with a smaller blue standard will cause high error of the assessment ;
②For pile fabric, the surface should be avoided to be flattened by the covering;
③For loose fibers, arrange them into thin layers and attach them to the hard card.
(2) rating process.
① Photochromism should also be taken into account. This is mainly manifested in the rapid discoloration of textiles after a brief period of exposure to light but in storage Put in the dark will be restored to the original color
② For hue changes, whether it is fading or hue changes, the sun-like cloth color is assessed visually, and any hue changes are also included in the assessment.
③In the testing process, we should always pay attention to the four displayed values of the instrument, namely irradiance, blackboard temperature, temperature in the test compartment, humidity changes in the test compartment to improve the accuracy and weight of the test。
