When enamel manufacturers test whether the color of enamel products meets the target requirements, they usually use a colorimeter. So how to use the colorimeter correctly and how to read the value of the colorimeter? Today, Xiaonuo is dedicated to talking about it for you.

When using a colorimeter, first use the colorimeter to measure the primary color of the standard sample color, and then measure the value of the tested sample, and calculate the color difference between the target and the tested sample according to the formula. When measuring with a colorimeter, two sets of data can be measured, one is L, a, b values, and the other is X, Y, Z values. Both of these two values ​​can be used to represent color characteristics, the most commonly used are L, a, b data, which can be automatically calculated and read directly by a colorimeter.

In the L, a, b data, L represents the lightness, such as L=0, that is, the chromaticity standard is black; such as L=100, that is, the chromaticity standard is white; a represents the degree of change from red to green, with +a The difference between the value of +a and -a, the greater the value of +a, the heavier the red, the greater the absolute value of -a, the heavier the green; b represents the degree of change from yellow to blue, there are +b and -b points, + The larger the b value, the heavier the yellow, and the larger the absolute value of -b, the heavier the blue.

According to the L, a, b values ​​measured by the standard sample and the measured object, the whiteness (W) of the measured object and the color difference (ΔE) between the sample and the object to be rubbed can be calculated.

Assuming that the L, a, b values ​​of the standard sample color are L, a, b, and the L, a, b values ​​of the measured object are L1, a1, b1, the whiteness of the measured object:

W= (100-L1) 2 + a1 2 b1 2 , the color difference ΔE value between the target color and the measured object is:

ΔE=(L-L1)2+(a-a1)2+(b-b1)2

According to the value of ΔE, it is judged whether it meets the requirements.

ΔE0~0.5: means no color difference

ΔE0.5~1.5: Indicates slight color difference

ΔE1. 5~3: Indicates medium color difference

ΔE> 3: Indicates severe chromatic aberration

Generally, the ΔE value is good at 0~1.5, moderate in 1.5~3, and poor if it exceeds 3.

X, Y, and Z in the second set of data represent the content of the three primary colors (red, green, and blue) of the measured object, X+Y+Z=1. According to the values ​​of X and Y, it can be in the X-Y standard color range Find the position of the color of the object to be measured on the (tongue diagram), that is, the dominant wavelength and color saturation (that is, the purity) of the color can be obtained.