FGD-4300 Fixed Electrochemical Toxic Gas Detector 316L Sensor Cap 0.1 ppm Resolution H2S CO

FGD-4300 Fixed Electrochemical Toxic Gas Detector

The FGD-4300 is a fixed electrochemical detector for continuous toxic gas monitoring at ppm and sub ppm levels: hydrogen sulphide in sewers and sumps, carbon monoxide in boiler and parking areas, ammonia in cold stores and chlorine in water treatment rooms. The upgrade responds to three field issues: cross sensitivity that produced false alarms, sensor caps that clogged in dirty atmospheres, and cartridges that were difficult to replace.

Higher Accuracy Than Previous Generation

• Accuracy of plus or minus 2% of reading with 0.1 ppm resolution, sufficient to detect exposure well below occupational limits.
• Improved selectivity through a filtered electrolyte and bias circuit, reducing the cross sensitivity to hydrogen that caused false H2S alarms in battery rooms and refineries.
• Temperature compensation from -40 to 60 degrees Celsius keeps readings linear in cold plant areas, where uncompensated cells typically read 10 to 15% low.
• Each cartridge is supplied with an individual calibration certificate and lot traceability for compliance records.

Improved Detector Performance

• Response time T90 below 15 seconds for H2S and CO, allowing timely evacuation alarms in confined spaces.
• Internal event log keeps the last 200 alarms with time stamps, which supports incident investigation without a separate data logger.
• Two alarm relays plus 4-20 mA and RS485 Modbus; alarm set points configurable over Modbus from the control room.
• Cartridge replacement is a single operation in the field, with automatic recognition of the installed gas type, so no reconfiguration is required.
• Sensor life indication on the LCD warns before end of life, avoiding an unexpected loss of detection.

Upgraded Materials and Construction

• 316L stainless steel housing and sensor cap replace the previous plastic and aluminium parts, resisting H2S, chlorine and caustic attack.
• PTFE membrane on the sensor cap resists clogging by dust, oil mist and salt deposits while remaining permeable to the target gas.
• Stainless steel sintered disc protects the electrolyte from particulate ingress in sewers and digester areas.
• IP66 sealing and marine grade fasteners suit washdown areas and coastal plants.

Technical Specifications

Typical Applications

• Wastewater collection systems, manholes and wet wells
• Boiler rooms, car parks and tunnel ventilation monitoring
• Cold storage and food processing ammonia detection
• Water treatment chlorine and sulphur dioxide rooms
• Refinery and petrochemical confined space monitoring

Calibration and Maintenance

Cartridges are bump tested monthly and calibrated every three to six months depending on the gas and environment. Replacement cartridges arrive pre-calibrated with a certificate, and the detector reads the gas type automatically. A calibration adapter and gas regulator are available as an accessory kit.

Ordering and Support

Each detector is supplied with a calibration certificate, sensor cartridge, weatherproof sunshade, mounting bracket and operation manual. Optional items include a calibration cup, duct mounting kit, remote display and HART or Modbus gateway. Our technical team supports configuration, bump testing schedules and spare sensor supply.

Contact our sales team for a quotation, datasheet or sample evaluation unit.