MOD-6400 Sulphur Analyzer utilizes field-proven ultraviolet (UV) fluorescence technology to continuously monitor the Total Sulphur content found in gasoline, diesel and other petroleum products. UV-Fluorescence is a non-consuming method of detection, eliminating the hassles associated with replacing tape cartridges, and enables detection as low as 
10 ppb, depending on application, with stable, reproducible results.
The analyzer is designed to meet technical requirements of ASTM D5453 and ASTM D6667. 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 vibration 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 Sulphur content found in the sample.
The converted sample gas is passed from converter, through a dryer for water removal, and directly onto the UV Fluorescence Analyzer where the SO2 Analysis takes place and is conveniently displayed, as Total Sulphur, for the operator to view.
The Series MOD-6400 is a single or multi-stream analysis system solution which provides the end-user with a wide variety of links to ensure effective system operation. In addition to conventional 4-20mA outputs for tracking the Total Sulphur concentration, the MOD-6400 can also provide a number of discrete I/O's as well as a bidirectional RS-232/RS-485 and Ethernet communication capability. This enhanced system communication capability allows the end-user to maintain an up-to-the-minute status of how the system is functioning and allow for a remote calibration or range change, should process changes so dictate.
Superior flow and temperature control of liquid-phase samples via Quartz Tube Converter Module Pyrolysis Technology ensuring high reliability and repeatability. In addition, the analyzer has a wide range of analyzer diagnostic capabilities to continuously provide plant operators with system status conditions.
