Industrial and Commercial Use Point-type Combustible Gas Detector Supplier & Factories in Sri Lanka

Catalytic combustion sensors (pellistors) operate via high-temperature catalytic oxidation of flammable gas on an active ceramic bead, creating a temperature differential across a Wheatstone bridge proportional to the gas concentration. They are cost-effective and detect virtually all combustible hydrocarbons, Hydrogen (H2), and Syngas. However, they require oxygen (>10% O2) to function and can be poisoned by airborne lead, siloxanes, and chlorine compounds.

Non-Dispersive Infrared (NDIR) sensors detect gas by measuring the specific absorption wavelength of hydrocarbon chemical bonds (typically 3.3 to 3.4 microns). NDIR sensors do not require oxygen, are completely impervious to chemical poisoning, and offer extraordinary long-term zero stability, making them ideal for high-humidity coastal chemical installations across Sri Lanka, though they cannot detect non-hydrocarbon gases like Hydrogen.

Detector positioning strictly depends on the relative vapor density of the target gas compared to ambient air (Air = 1.0):

• LPG (Propane/Butane): Vapor density is approximately 1.5 to 2.0 (significantly heavier than air). Leaked gas sinks and pools along floor channels, trenches, and low-lying corners. Point-type detectors must be mounted 0.3 meters to 0.6 meters above the finished floor level, within 1.5 meters to 3 meters horizontal radius of gas-burning stoves, piping manifolds, or storage cylinders.
• Natural Gas / Methane (CNG): Vapor density is approximately 0.55 (lighter than air). Gas rises instantly toward the ceiling. Detectors must be mounted within 0.3 meters to 0.5 meters below the ceiling, positioned directly above the potential leak source.

Industrial manufacturing plants, bulk solvent depots, and refinery terminals generally classify hazardous locations according to IEC / ATEX zoning guidelines. For Zone 1 areas (where an explosive atmosphere is likely to occur in normal operation), detectors must possess flameproof certifications: Ex d IIC T6 Gb or intrinsic safety Ex ia IIC T4 Ga.

The "Ex d" designation guarantees that if an internal gas deflagration occurs inside the detector housing, the flame path will quench the explosion pressure internally, preventing ignition of the external explosive environment. Our SD2100 series features heavy-duty die-cast aluminum explosion-proof construction certified for Zone 1 and Zone 2 operations.

Yes. We engineer both bus/branch centralized detectors and completely autonomous stand-alone detectors:

• Autonomous Models (SD2130 Series): Feature built-in 85dB audible sounders, high-visibility LED alarm rings, and internal dry-contact relay outputs. They directly switch 24VDC or 220VAC power circuits to trigger emergency solenoid cut-off valves (like our JYFJS-011) or activate localized explosion-proof ventilation fans without requiring a controller panel.
• Networked Models (SD2100A / SD2100E): Designed for multi-point facilities where dozens of detectors wire via 4-20mA current loop or 4-wire M-BUS / RS485 Modbus RTU back to a centralized control console (such as the SD8001A/B) located safely in the non-hazardous engineering room.

In equatorial maritime climates like Sri Lanka, high ambient humidity and temperature fluctuations accelerate catalytic bead aging. We recommend the following schedule:

• Bump Testing (Functional Response Check): Every 3 to 6 months. A known concentration of calibration gas (e.g., 50% LEL Methane or Propane balance air) is briefly introduced to verify sensor responsiveness and alarm relay linkage.
• Span & Zero Full Calibration: Every 6 to 12 months. Calibrating zero in fresh ambient air followed by span calibration using certified span gas cylinders. Our SD2100 series supports non-intrusive infrared remote adjustment, allowing calibration without opening the explosion-proof housing.

Standard model orders are dispatched from our factory within 5 to 10 working days. For bulk project shipments to Sri Lanka, cargo is routed via air freight directly to Bandaranaike International Airport (CMB) for urgent installations, or sea container freight arriving at the Port of Colombo (transit time typically 12 to 18 days from Chinese main ports).

We provide full documentation packages required by Sri Lanka Customs and the Sri Lanka Standards Institution (SLSI), including commercial invoices, packing lists, Certificates of Origin (CO), Factory Calibration Certificates, and CCC / IECEx / CE conformity documentation.