A spectrophotometer, also known as a spectrometer, is a scientific instrument that decomposes complex light into spectral lines. The measurement range generally includes the visible light region with a wavelength range of 380 to 780 nm and the ultraviolet light region with a wavelength range of 200 to 380 nm.
 
Types of spectrophotometer：
1. Visible spectrophotometer
The instrument used to measure the absorbance of the substance to be tested against visible light (400-760nm) and perform quantitative analysis is called a visible spectrophotometer. It can measure the bacterial cell density at 600nm.
2. Ultraviolet visible spectrophotometer
Ultraviolet-visible spectrometer is an instrument used to measure the absorbance of visible light or ultraviolet light (200-760nm) of the substance to be tested and perform quantitative analysis. It can measure the concentration of nucleic acid and protein, as well as the density of bacterial cells. The UV spectrophotometer can be divided into single beam, pseudo double beam, and double beam.
3. Infrared spectrophotometer
The general infrared spectrum of a spectrophotometer refers to the infrared spectrum greater than 760nm, which is the most commonly used spectral region for studying organic compounds, and it can be used to analyze samples in various states (gas, liquid, and solid).
4. Fluorescence spectrophotometer
Fluorescence spectrophotometer is an instrument used to scan the fluorescence spectrum emitted by liquid-phase fluorescent markers, which is used in scientific research, chemical industry, medicine, biochemistry, environmental protection, clinical inspection, food inspection, teaching experiment and other fields. By measuring these parameters, it can not only do general quantitative analysis, but also infer the conformational changes of molecules in various environments, thereby clarifying the relationship between molecular structure and function.
5. Atomic absorption spectrophotometer
It is mainly used as one of the conventional instruments for the analysis of micro and trace components in samples. It is a powerful tool for the analysis of major and trace metals (semi-metals) in the material analysis and quality control departments.
 
The spectrophotometer can calculate the color information under various light sources by obtaining reflectance or transmittance data, including parameters such as reflectance, transmittance, color difference, yellowness, and whiteness. Spectrophotometer is an instrument commonly used in biology, chemistry, clinical and environmental research.