A colorimeter is an instrument widely used in the field of color measurement and quality control, which can accurately measure the color difference between two samples. However, when performing colorimeter calibration, it is common to perform only black and white calibration without color calibration. Why is that?This article will unravel this mystery for you.
First, we need to understand how a colorimeter works. A colorimeter calculates the value of color by measuring the reflected light from the surface of an object. When light hits the surface of an object, a part of the light is absorbed and a part of the light is reflected. A colorimeter calculates the color value of an object by measuring the intensity and spectral distribution of the reflected light.
During calibration, the colorimeter needs to calibrate its own measurements using a known standard color. Black and white calibration is one of them. When performing a black-and-white calibration, the colorimeter measures the black-and-white card and the white standard and corrects its own measurement error by comparing the difference between the measurement result and the standard value. This calibration is simple and easy, and since black and white color accounts for most of the energy in the spectrum, black and white calibration can effectively correct the measurement error of the colorimeter.
So why don't we do color calibration?This is because color calibration requires the use of a multi-colored standard plate, each of which requires precise values and stability. Not only does this make calibration more difficult and costly, but it is also unnecessary in practical applications. Because when we use a colorimeter for color measurement, we usually only need to measure the color difference between two samples, rather than accurately measuring the specific color value of each sample. Therefore, as long as the colorimeter has achieved sufficient accuracy in the black and white calibration, it can meet the needs of most color measurements.
In addition, the color calibration is affected by ambient light. Both the spectral distribution of ambient light and the intensity of light have an impact on the color calibration, which in turn affects the accuracy of the calibration results. In order to avoid this effect, we need to strictly control the conditions of the ambient light, which is very difficult in practice. The monochrome calibration criterion is not affected by ambient light, as the monochrome card performs consistently in any lighting condition.
In summary, the colorimeter is calibrated only in black and white without color because black and white calibration has the advantages of easy operation, low cost, meeting most color measurement needs, and is not affected by ambient light. In practical applications, we only need to carry out black and white calibration to ensure the measurement accuracy and accuracy of the colorimeter. Of course, for some special applications, such as high-precision color research and quality control in special industries, a higher level of calibration methods may be required to meet specific needs.