Honeywell Searchline Excel

Honeywell Searchline Excel is an established infrared open-path flammable gas detector, deployed in tens of thousands of installations from Arctic facilities to Middle Eastern deserts. Its line-of-sight design measures gas concentration across a beam rather than at a single point, making it more likely to detect a flammable gas cloud in open or ventilated areas. By indicating the size of the hazard along the path (LEL.m), it provides more informative data than simple point readings and can often replace or reduce the number of point detectors, lowering project complexity while improving coverage.

The detector delivers ultra-high sensitivity and a very fast T90 response under normal operating conditions, enabling low but stable alarm set points. This supports early detection of small leaks before they develop into larger incidents, helping operators initiate timely intervention and controlled shutdowns. The wide measuring range, combined with consistent performance across all path-length variants, allows practical alarm settings that balance early warning with nuisance-alarm avoidance.

Searchline Excel is designed to operate reliably from -40 °C to +65 °C and across typical industrial humidity and pressure ranges without additional compensation. A patented optical design using a xenon flash lamp, brighter than the sun at infrared wavelengths with a unique pulse shape, provides robust signal discrimination. The detector is immune to interference from sunlight, flare stacks, arc welding, lightning and other radiation sources, helping maintain integrity on complex process units and offshore structures.

A patented double band-pass filter compensates for fog, rain, mist and other adverse weather, while integral window heating helps reduce the impact of ice and condensation. Contamination-resistant optics and an electropolished 316 stainless-steel housing with high ingress protection ratings support long-term durability in harsh, corrosive, marine and coastal environments. High vibration resilience and a shock-resistant mechanical design keep the system online around heavy machinery, pipelines and offshore assets.

Short-, medium- and long-path versions allow a single platform to cover process areas, loading bays, corridors, tank farms, perimeters and large open spaces. Because the detector measures along a beam, exact location is less critical than for point detectors, which simplifies layout on congested pipe racks and structures. A sample-and-reference detector arrangement reduces sensitivity to alignment errors and partial obscuration, while generous tolerance to duct flex, vibration and structural movement supports stable performance over time.

Searchline Excel is engineered to streamline installation and commissioning. Its alignment-free or low-sensitivity-to-alignment behaviour makes setup more forgiving, particularly on long paths or where structures can move. For precise alignment, the system is supplied with robust tools including a high-power rifle telescope for extended ranges.

Alignment software, accessed via a handheld interrogator, provides confirmation of alignment quality and signal levels and assists with compatibility checks to existing systems. A wide choice of pre-wired configurations, stainless-steel mounting hardware, sunshades, Ex e junction boxes, DX termination units and regional thread options (such as metric and NPT) allows standardisation of hardware across sites with differing local practices.

Built-in fault diagnostics provide clear status information via the 4–20 mA output, including over-range, dirty optics, beam blocked and general fault indications, helping technicians pinpoint issues quickly. Dedicated beam-block and dirty-optics signals support proactive cleaning and inspection before performance is affected. An integral functional gas test facility enables straightforward, regular functional checks without complex procedures, assisting sites in meeting test requirements with less disruption.

Contamination-resistant optics, high vibration tolerance and rugged mechanics help minimise unscheduled interventions. Field configuration and servicing in hazardous areas using non-intrusive handheld interrogators and smart junction box solutions further reduce the need for intrusive work, cutting downtime and simplifying maintenance planning.

The infrared open-path measuring principle allows Searchline Excel to operate in inert or low-oxygen atmospheres where conventional catalytic detectors may be unsuitable. It is not affected by water vapour and is immune to catalytic poisons, supporting reliable detection in complex process areas and ventilation-affected zones. Fully temperature-compensated solid-state detectors help maintain accuracy across the full operating temperature range, including during cold starts or rapid environmental changes.

Searchline Excel integrates readily into new and existing safety systems via 4–20 mA analogue output with selectable source or sink operation and RS-485 Modbus communication. Optional multi-drop Modbus configurations can be implemented using DX100(M) termination units or XNX universal transmitters, enabling networked monitoring over large facilities. Compatibility with Honeywell XNX, OELD and other controllers supports a consistent platform approach across the asset base.

An extensive accessory ecosystem includes alignment kits, handheld interrogators, mounting plates, U-bolts, sun and snow covers, heat shades and adapters, making it straightforward to adapt installations for onshore, offshore, building and perimeter applications. Different power profiles for each transmitter range and the receiver help optimise power consumption, supporting large-scale deployment. Multiple regional certifications and matching junction boxes facilitate global standardisation while meeting local hazardous-area requirements.

Drawing on the heritage of Sieger and Zellweger Analytics and developed in collaboration with major international oil and gas companies, Searchline Excel reflects real-world operating demands. Typical applications include upstream production, downstream chemical processing, gas transport and pipelines, large storage facilities, buildings, offshore platforms, FPSOs and perimeter detection. Fast warm-up and stabilisation after power-up or maintenance help minimise downtime, while proven field experience provides assurance for operators seeking high-integrity open-path flammable gas detection across the asset lifecycle.

For detailed technical data, consult the Specifications tab.