Color is one of the important symbols to measure the quality of oil and the value of commodities. At present, the quality standards of edible vegetable oil at home and abroad generally stipulate that the color should be determined by the Lovibond P colorimetric method. The grain system in my country is equipped with a certain number of Lovibond Colorimeters to meet the needs of the work. However, domestic and foreign chemical industry stipulates that the color of industrial vegetable oil shall be determined by the iron diamond colorimetric method (the standard evaluation method of liquid Gardner color). Some vegetable oils, such as linseed oil, soybean oil, and perilla oil, are not only edible oils, but also can be used as raw materials in the paint and ink industries. The determination of the color index of these oils and fats uses the Lovibond Colorimeter method in the food sector, and the iron-diamond ratio in the chemical sector. The color meter method is not uniform, and it is undoubtedly meaningful to obtain a comparison table between the two methods. We first prepared 18 levels of iron diamond Colorimeter standard color scale solution, and then measured the color value of each level of color scale solution with Lovibond Colorimeter, so as to obtain the comparison table of the two methods. In practical application, after the Lovibond color value of oil is measured, the possible color value measured by the iron diamond Colorimeter method can be known by looking up the table.
