单色光源的光学分辨率——测量半峰宽(FWHM)——取决于光栅的刻线密度(mm-1)和入射光学系统的直径(光纤或狭缝)。配置您的光谱仪时,需要考虑两个非常重要的权衡:
如何计算光学分辨率的近似值,单位nm(FWHM)
离散值(nm/pixel)=光栅的光谱范围/检测器像元的数量
下面的表格列举了各种光谱仪工作台和模块的检测器像元数
Spectrometer | Number of Detector Elements |
Spark | 1024 |
STS | 1024 |
USB2000+ | 2048 |
USB4000 | 3648 |
Flame-T | 3648 |
Flame-S | 2048 |
HR2000+ | 2048 |
HR4000 | 3648 |
Maya2000 Pro | 2048 x 64 (active) |
QE Pro | 1044 x 64 (total pixels) |
NIRQuest 256 Series | 256 |
NIRQuest 512 Series | 512 |
各种狭缝尺寸(或光纤直径,如果光纤是制约因素时)的像素分辨率在下面列举出。狭缝入瞳的宽度不同,但高度相同(1000microns)。
Spectrometer | 5 micron | 10 micron | 25 micron | 50 micron | 100 micron | 200 micron |
USB2000+ | ~3.0 pixels | ~3.2 pixels | ~4.2 pixels | ~6.5 pixels | ~12.0 pixels | ~24.0 pixels |
USB4000 | ~5.3 pixels | ~5.7 pixels | ~7.5 pixels | ~11.6 pixels | ~21.0 pixels | ~42.0 pixels |
Flame-T | ~5.3 pixels | ~5.7 pixels | ~7.5 pixels | ~11.6 pixels | ~21.0 pixels | ~42.0 pixels |
Flame-S | ~3.0 pixels | ~3.2 pixels | ~4.2 pixels | ~6.5 pixels | ~12.0 pixels | ~24.0 pixels |
HR2000+ | ~1.5 pixels | ~2.0 pixels | ~2.5 pixels | ~4.2 pixels | ~8.0 pixels | ~15.3 pixels |
HR4000 | ~2.0 pixels | ~3.7 pixels | ~4.4 pixels | ~7.4 pixels | ~14.0 pixels | ~26.8 pixels |
NIRQuest | N/A | ~1.3 pixels | ~2.0 pixels | ~2.3 pixels | ~4.2 pixels | ~7.9 pixels |
NIRQuest | N/A | ~1.5 pixels | ~1.7 pixels | ~2.0 pixels | ~2.5 pixels | ~4.0 pixels |
Maya2000 Pro | ~1.5 pixels | ~2.0 pixels | ~2.5 pixels | ~4.2 pixels | ~8.0 pixels | ~15.3 pixels |
QE Pro | ~2.0 pixels | ~2.2 pixels | ~2.6 pixels | ~3.3 pixels | ~4.7 pixels | ~8.9 pixels |
离散值(步骤2)x像素分辨率(步骤3)
例子:确定#3光栅和10 micron狭缝的USB4000光谱仪的光学分辨率
650 nm (#3光栅的光谱范围)/3648 (USB4000的检测器像元数) = 0.18 nm/pixel x 5.7 pixels = 1.0 nm (FWHM)
注意:数值四舍五入至最接近的十进制数