Mercaptan Sulfur Tester determines mercaptan sulfur content present in petroleum products with help of the computer. This detection method is based on principle of Potentiometric titration method. It offers 0 to ±1999.5 Mv potential measuring range and 3 to 100 μg/g (ppm) Mercaptan sulfur measuring range. It ensures the accuracy of the results by titration curve smoothing and titration end position correction. It is used in laboratory, analysis room and petrochemical research departments of the ideal of the necessary device. Mercaptan Sulfur Tester detection method meets the international standard ASTM D3227.