The CX-9900 adopts an optical system that was previously only used on laboratory instruments, and has been specially improved to meet the needs of portable spectrometers. It can receive and analyze all elemental spectral lines within the wavelength range of 170nm-530nm, with good accuracy and stability. The various components in the optical system, such as gratings (focal length 400mm) or high-precision detectors, are well fixed and protected, making the instrument dustproof, earthquake resistant, sturdy and durable.