Model 6400-TSG Total Sulfur in Fuel Gas Analyzer
Using UV-Fluorescence detection technology


  • Refinery flare monitoring – 40 CFR 60 Subpart Ja installations
  • Hydrogen plant steam methane reformer (SMR) for catalyst protection
  • LNG monitoring of sulfur impurities
  • Refinery feed gas to hydrogen plant

This Model 6400-TSG system uses UV-Fluorescence detection technology to analyze total sulfur concentration in gas samples. It consists of a Model 6400E UV Fluorescence Sulfur Dioxide Analyzer, a Flame Combustion Converter Module (FCCM), and associated sample handling required per application. The system is housed in a freestanding NEMA-4 or NEMA-4X rated enclosure with approved purge, making it suitable for operation in Class I Div 1 (Zone 1) or Class I Div 2 (Zone 2) environments.


  • Trace and percent analysis ranges available
  • Continuous analysis – fast response time and no switching valves
  • Non-consumable sensing technology
  • High-temperature flame combustion converter module ensures complete sulfur conversion
  • Minimal preventative maintenance for less down-time
  • No pure oxygen required as a utility gas
  • Single and multiple sequenced stream configurations available
  • Speciating configurations available using integral chromatography
  • Class I Div 1 (Zone 1) and Class I Div 2 (Zone 2) configurations available

Theory of Operation

The undesirable sulfur compounds present (i.e. H2S, DMS, COS, CH3SH, CS2, etc) are converted into sulfur dioxide (SO2) under precisely controlled temperature and flow conditions.

SO2 + hv¹ -> SO2*-> SO2 + hv²

When SO2 is exposed to UV light energy, hv1, it creates an “excited” form of sulfur dioxide, SO2*. A molecule in a high, vibrational level of the excited state, SO2*, will quickly fall to its lowest vibrational level by losing energy to other molecules through collision. Fluorescence occurs when the molecule returns to its electronic ground state. The intensity of the emitted light, hv2, is directly proportional to the total sulfur content found in the sample.

The converted sample gas is dried, then fed to the Model 6400E UV Fluorescence Analyzer where the SO2 Analysis takes place and is conveniently displayed as Total Sulfur.


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