Double Focusing Hot Surface Ionization Mass Spectrometer (DF-TIMS) Based on the team's years of experience in the research and design of magnetic mass spectrometers, combined with the latest technological advances, a double-focused hot Surface ionization mass spectrometer (DF-TIMS) for high-precision isotope ratio analysis has been developed. The instrument offers excellent linearity and stability, providing reliable test data from elements Li to U.