UV/ VIS Single/ Double Beam Spectrophotometer ensures high performance with an optical bench that is equipped with a monochromatic allowing for trouble-free operation and is used for transmission spectroscopy in the range from 190 nm to 1100 nm. The Spectrophotometer has a tungsten lamp that covers the region from 350 nm to 1100 nm, and a deuterium lamp that covers the region from 190 nm to 350 nm and the instrument can be used in a scanning spectrum mode, a kinetics mode, and a quantitative analysis mode. The Spectrophotometer has wavelength range from 190 to 1100 nm, humidity 45 to 80% and bandwidth of 2 nm. The Spectrophotometer has scanning speed of 3200 nm/ minute to 160 nm/ minute and silicon photodiode detector. The Spectrophotometer has aberration correcting concave blazed holographic grating and interior dimension of 110 X 230 X 105 mm. The Spectrophotometer has distance between beams of 100 mm, wavelength setting of 0.1 nm increments and wavelength slew rate of about 6000 nm/ minute. The UV/ VIS Single/ Double Beam Spectrophotometer has photometric accuracy of ± 0.004 abs at 1.0 abs.