MOD-4100 crude oil analyzer is configured in accordance with customer’s request to provide on-line data about the density, the salt content, the viscosity, the water content and the content of hydrogen sulfide. This information is highly important for preventing corrosion, fouling and plugging of the pipelines and production units at the refinery, and for optimized operation of blending, desalting and distillation processes. Furthermore, it provides an effective tool for on-line verification of the crude oil quality according to its specifications.