Double-beam optical system of spectrophotometer

The utility model discloses a double-beam optical system of a spectrophotometer, which comprises a light source assembly including a tungsten lamp, a deuterium lamp and a mercury lamp; the light decomposition assembly comprises a first collimating mirror, a second collimating mirror and a grating, the first collimating mirror receives the light emitted by the light source assembly and reflects the light to the grating, and the grating reflects the light to the second collimating mirror; the light splitting assembly comprises a chopper mirror, the chopper mirror receives the light emitted by the light decomposition assembly and then divides the light into two paths of light, and the two paths of light enter a first reference light path and a second reference light path respectively; wherein the first reference light path and the second reference light path receive light, detect a sample and then reflect the light to the photomultiplier. According to the utility model, the wavelength precision is high, the inst