Sulfur analyzer H2S/TOS TS MEDOR®

gashydrogen sulfidefor hazardous environments

Product overview
The H2S/TOS TS MEDOR® is an autoGC-ED (MEDOR® Electrochemical wet cell Detector) designed for continuous online analysis and monitoring of hydrogen sulfide (H2S), total organic sulfur (TOS) and total sulfur (TS). Available configurations include ppb and ppm measurement ranges to suit trace to mid-level concentrations.

Principle

• Automatic sampling using a sample loop
• Automatic loop injection onto a metallic capillary column
• Isothermal gas chromatograph operation
• Detection performed by the MEDOR® electrochemical wet cell detector (sulfur specific detector, SSD) for all compounds eluting from the column
• Signal generated by electrochemical reaction between wet cell electrolyte and sulfur compounds
• Fully compliant with ASTM D 7493-14 for on-line GC and electrochemical detection
• Compatible with ASTM D 5504-20 when using chemiluminescence as alternative detection

Technical specifications

• Detection limits: ppb version: 5 ppb H2S (7 μg/m3); ppm version: 0.1 ppm H2S (0.1417 mg/m3)
• Detection range: Selectable 0/10, 0/100 or 0/1000 (ppb or ppm); low-% measurement possible with HC sampling valve
• Relative Standard Deviation (RSD): < 3% on concentration over 48 h; < 0.6% on retention time over 48 h
• Results / Outputs: On-board storage; MODBUS communication protocol (optional); 4-20 mA outputs (optional)
• Linearity: R2 ≥ 0.995 for tested compounds
• Cycle time: ~2 min for H2S/TS in low-range (0–3 ppm); ~5 min for higher ranges
• Gas supply: Carrier gas: dry air or N2 (3 bar) at 5 ml/min; CALIB continuous 50 ml/min (option); CALIB during validation ~250 ml/min (option); pneumatic valve consumption 90 ml per commutation

Key points

• Continuous monitoring with automatic online sampling and injection
• Analytical performance: sulfur-specific, linear and highly sensitive detection; automated validation via standard injection; long-term stability with detector housed in a reservoir
• Low maintenance: extended detector lifetime with electrolyte (up to 10 years); low gas consumption (reducible by option); on-board data storage for more than 10 years; internal calibration tube and gas generators reduce or remove need for cylinders
• Automatic process control with configurable interactive alarm levels
• VISTACHROM Chromatotec® software for remote monitoring and injection control; full traceability with onboard archiving of results and chromatograms

Configurations

• ppb configuration for trace monitoring (0–1 ppm equivalent range)
• ppm configurations available for 0–10, 0–50 and 0–100 ppm ranges
• Low-% measurement capability with HC sampling valve

Standards, approvals & certifications

• Compliant with ASTM D 7493-14
• Compliant with ASTM D 5504-20 (alternative detector method)
• ATEX and IECEx certification for hazardous area use (Zone 1, Group IIC, T4)
• GOST certification available for relevant models

Technical characteristics

• Detector type: MEDOR® electrochemical wet cell detector (sulfur specific)
• Detection limits: 5 ppb (ppb version) / 0.1 ppm (ppm version)
• Selectable detection ranges: 0/10, 0/100, 0/1000 (ppb or ppm)
• Cycle time: typically 2 min for low-range (0–3 ppm); 5 min for higher ranges
• Linearity: ≥ 0.995
• RSD: < 3% concentration (48 h); < 0.6% retention time (48 h)
• Carrier gas: dry air or N2, 3 bar, 5 ml/min
• Calibration flows (options): continuous 50 ml/min; validation ~250 ml/min
• Communications: optional MODBUS, optional 4-20 mA outputs
• Compliance: ASTM standards, ATEX/IECEx, GOST (as applicable)