Crowcon Smart 3G-C3

The Crowcon Smart 3G-C3 fixed gas detector is designed for safety-critical environments where functional safety, uptime and traceable performance are essential. SIL2-certified hardware combined with SIL3 software supports high integrity gas detection in line with demanding industrial safety requirements. In redundant system architectures, Smart 3G-C3 hardware can be applied to achieve even higher safety levels, making it suitable for high-risk applications such as refineries, chemical plants, manufacturing facilities and other hazardous processing areas.

By continuously monitoring toxic, flammable, VOC and refrigerant gases together with oxygen, the detector provides early warning of potentially explosive, asphyxiating or harmful atmospheres. A single platform capable of detecting over 50 target gases enables consistent engineering, standard operating procedures and documentation across sites.

For detailed technical data, consult the Specifications tab.

The Smart 3G-C3 supports catalytic, infrared (IR), electrochemical and photoionisation (PID) sensor technologies, allowing the sensing method to be matched to the gas hazard and application. Catalytic pellistor sensors provide high linearity up to 100% LEL for flammable gases, while poison-free infrared sensors offer accurate, stable and long-lived measurement for flammable and refrigerant gases.

Dedicated IR ranges for carbon dioxide and options for gases such as SF6 support specialised applications, while electrochemical sensors cover common toxic gases including ammonia, carbon monoxide, hydrogen sulphide, nitric oxide and ethylene. Refrigerant gas capability spans established HFCs and new-generation low-GWP refrigerants, supporting both legacy and modern refrigeration and cooling systems. This breadth of coverage allows one detector family to address combustion, process, refrigeration and asphyxiation risks across a site.

An explosion-proof aluminium enclosure combined with a stainless steel sensor head provides mechanical robustness and corrosion resistance for demanding industrial locations. Smart 3G-C3 is suitable for gas hazardous areas such as those found in oil and gas, petrochemical and general process industries. With the appropriate dust adapter, the detector can also be applied in combustible dust atmospheres, extending coverage from gas-only (G) to gas and dust (GD) applications, including Zone 22 areas.

Protection concepts include Ex d flameproof, Ex e increased safety, Ex nC enclosed and Ex t dust ignition protection (with adapter), as applicable to the chosen configuration. An IP55 enclosure rating (certification pending) offers protection against dust and water jets, supporting use in washdown areas, outdoor installations and marine or offshore environments. Operating temperatures from -40 °C to +60 °C and a wide humidity range further support reliable performance in harsh climatic conditions.

The Smart 3G-C3 is engineered for straightforward integration into existing control and safety architectures. A standard 4–20 mA 3-wire analogue output interfaces readily with typical industrial control panels, DCS and PLC systems. Optional RS485 connectivity with Modbus protocol enables digital communication, multi-drop installations and integration with multi-channel controllers and supervisory systems.

Optional 1- or 3-relay output boards provide local alarm contacts for sounders, beacons, valves or interlocks directly from the detector. This helps streamline panel design and can reduce the requirement for additional interface modules. A 12–24 Vdc supply range and power consumption around 5.4 W support energy-efficient system design. Compact enclosure dimensions and a single M20 cable entry simplify routing, mounting in confined spaces and field wiring.

Smart 3G-C3 is designed for long-term stability and reduced lifecycle cost. Continuous self-diagnosis monitors detector health and provides early fault indication, supporting planned maintenance strategies and minimising unplanned interventions. Zero follower and drift compensation features enhance long-term measurement stability and help maintain performance between scheduled calibrations.

Predicted sensor lifetimes of typically 4–5+ years reduce replacement frequency and associated labour. When replacement is required, the detector allows easy sensor access and exchange to keep downtime short, an important consideration during tight shutdown windows. Regular calibration at intervals typically between 6 and 12 months can be supported using calibration software, keypad tools and associated accessories.

Calibration and configuration tools allow adjustment of alarm thresholds, measurement ranges and 4–20 mA output scaling either in situ or in the workshop, making it straightforward to align detector behaviour with site standards and regulatory requirements. Accessories support firmware updates and data logging via SD card, enhancing traceability and providing additional insight for maintenance planning and system optimisation.

Remote sensor head kits, available in multiple cable lengths, allow the sensing element to be positioned away from the transmitter body. This facilitates sampling at optimal gas accumulation points, including high-level or difficult-to-access areas, while keeping the transmitter accessible for service. Dust adapters extend the detector’s use into combustible dust environments, supporting gas and dust classified areas with the same core platform.

As part of the broader SMART 3G series, the Smart 3G-C3 enables standardisation of hardware, user interfaces and maintenance practices across varied plant areas, from general industrial zones to marine and offshore installations. Its combination of functional safety capabilities, hazardous area suitability, broad gas coverage and practical maintenance features helps operators meet safety obligations and maintain reliable protection of personnel, assets and processes.