BYK-Gardner offers a choice of two geometries in its handheld spectral waveguide Spectrophotometer s: 45/0 configuration and ad/8 spin sphere geometry. They also offer an "S" version of each version. This article discusses where each method is used and the measurement differences between them.
45/0 geometry
The 45/0 geometry has always been considered the workhorse of QC in the world. It measures the color and appearance of the sample versus the standard, so any difference in delta e (total color difference) will indicate that the sample does not match the standard. This leads to failure and requires modification of the sample/batch. The problem is that even if it tells you there's a fault, it can't easily tell you what caused it.
The 45/0 instrument illuminates the sample at an angle of 45° and detects it at a perpendicular vertical angle (0°). However, not all light that hits the sample makes it back to the Detector. Gloss plays a large role in color measurement when using a 45/0 instrument. The glossier the sample, the more light reflected back from the sample will reflect at the same 45° or at least somewhere between that mirror angle and the 0° Detector. This reflected light not measured by the Detector will result in a lowered L value in the color measurement. The "true" color brightness may be identical between the sample and the standard, but the apparent color brightness will be detected and reported. There is a problem that can be partially solved by looking at the difference in gloss between the sample and the standard. But adjusting the glossiness to zero difference may still show a chromatic aberration, which then needs to be resolved.
Because the spectroguide contains both a Spectrophotometer and a gloss meter, both results are displayed simultaneously, it is very quick and easy to determine whether a sample has the same appearance when compared to a standard, and also as to whether the difference is being caused by color , gloss, or both. This makes SpectraGuide a better workhorse solution for the typical quality control lab. It provides all the color and gloss information needed to pass or fail a product.
d/8 SPIN geometry
The d/8 spin (including specular) sphere instrument makes it easier to find differences between samples and standards. All light reflected from the sample bounces around the sphere and is sent back to the Detector. This means that the true color difference between the sample and the standard is being detected and reported. However, the "look" of the sample may still differ from the standard. Again, this is where the Spectrum Guide line of instruments has its great advantages. If the color difference is basically zero, and the gloss exceeds the specifications stored in the instrument, the instrument still fails the QC test. Therefore, it still measures the appearance of the sample according to the standard, but divides the appearance into two real measurements.
一般而言，45/0几何形状的仪器已用作检测所有外观差异的质量控制工具。d / 8自旋球仪已用于匹配颜色。但是，通过增加光泽度测量并将光泽度规范包含在光谱引导仪器中，45/0和d / 8球形仪器也都成为了非常好的QC工具。
光谱导向光泽度S解释
最后，将深入研究两种仪器的“ S”版本。光谱波导测量端口中包含的光泽度计可测量60°光泽度值。该角度适用于各种光泽度值，从大约10 GU（光泽度单位）到70 GU。但是，有些客户正在测量平均光泽值远低于10 GU正常测量范围的样品。对于这些客户，BYK-Gardner推出了“ S”单元，其在10 GU范围内的可重复性为±0.1 GU（与标准分光导板的±0.2 GU相比），并且在仪器之间的可重复性为±0.5 GU（相对于标准分光光度计的±1.0 GU。
购买光谱指南时，应考虑上述所有功能。但是，没有提到的一个功能是，您确实需要找出客户或供应商用来衡量您所提供或他所提供的材料的材料。例如，如果他向您提供使用典型的45/0仪器测量的材料并向您提供他的编号，那么如果您使用d / 8球面仪器，您的编号将不会接近他。另外，市场上有一些分光光度计可测量d / 8 spex球而不是自旋球。d / 8 spex的测量非常类似于45/0仪器。该反弹在镜面角的样本（在本例8°）的光从测量（SPEX =排除SP ecular 离鼓舞）如果您的客户/供应商使用的是Spex仪器，则即使他说他正在使用ad / 8球形几何图形，也应使用45/0光谱指南获取相似的数字。
Other factors to consider when purchasing a Spectrophotometer include the type of material to be measured, the surrounding environmental conditions, and the typical end user of the instrument. For example, polished metals often have color standards. However, if you try to measure with a 45/0 instrument, they will reflect almost all light at a 45° angle, and the measurement will appear almost black. Spherical instruments need to be used on metal surfaces. However, if used in a dusty environment or in the presence of strong chemicals, the ball will be much more expensive to maintain. The barium coating in the sphere may become dirty or yellow, necessitating a new sphere or recoating of the sphere. Under the same conditions, the 45/0 instrument only needs to be blown out quickly with a can of compressed air.
Unless your budget allows for frequent returns for cleaning and calibration, a 45/0 instrument should be used in any eventuality that environmental conditions are undesirable.
