Rosemount™ 936 Open Path Toxic Gas Detector

Description

Ultraviolet Technology Enables Reliable Long‑Range Gas Detection

The Rosemount 936 Open Path Toxic Gas Detector implements advanced ultraviolet absorption technology to achieve dependable, continuous monitoring of hydrogen sulfide (H₂S) and ammonia (NH₃) concentrations across industrial sites. Engineered for environments where dust, fog, or precipitation normally obscure optical signals, the 936 maintains measurement integrity through precisely modulated UV wavelengths between 200 and 300 nanometers, immediately identifying hazardous gas clouds from distances up to 200 feet (60 meters). By leveraging open‑path methodology rather than point‑source sampling, the system eliminates blind zones and enhances early‑warning capability, ensuring comprehensive coverage for perimeter and workspace safety. The detector’s UV source and receiver continuously compare signal attenuation against factory‑calibrated spectral profiles, producing rapid output with a time constant (T90) ≤ 3 seconds—ideal for emergency isolation or automatic ventilation control. Its design also includes high immunity to external interference such as solar radiation or hydrocarbon flames, preventing nuisance alarms. Through the 936’s real‑time diagnostic intelligence and automated compensation for humidity or optical drift, Emerson delivers an exceptionally reliable toxic‑gas defense platform ready for deployment anywhere sensitive atmospheric monitoring is required.

Extreme Environment Design With Heated Optical Components

Durability defines the Rosemount 936. The unit houses precision optics and electronic assemblies in a robust 316L stainless steel enclosure, specifically hardened for chemical plants, gas processing facilities, marine terminals, and arctic installations exposed to condensation or icing. Emerson integrates heated optical windows that actively prevent dew formation across lenses, maintaining clear transmission during sudden temperature drops or humidity spikes. Operability extends from –67 °F to +149 °F (–55 °C to +65 °C), enabling installation from desert pipelines to refrigerated industrial zones. In severe storms or offshore applications, the stabilized housing resists vibration and misalignment (±1° tolerance), preserving consistent alignment between transmitter and receiver components. These mechanical reinforcements minimize service requirements while sustaining calibration accuracy for years. The optical assembly further incorporates anti‑fog coatings and hydrophobic surface treatments designed to repel rain and salt mist, ensuring uninterrupted productivity in challenging climates. By combining environmental toughness and optical stability, the Rosemount 936 represents Emerson’s commitment to dependable detection—able to guard high‑risk areas without deterioration or false triggers. Whether confronting chemical mists in fertilizer plants or H₂S vapor pockets within gas recovery stations, this detector upholds long‑term functionality ensuring personnel safety under virtually any atmospheric condition.

Comprehensive Global Approvals Ensure Regulatory Compliance

Emerson certifies the Rosemount 936 Open Path Detector under a comprehensive portfolio of international safety approvals, making it ready for global deployment in multi‑national projects. Its conformance includes ATEX, IECEx, FM/FMC, INMETRO, and TR CU—covering Europe, North America, South America, the Middle East, and Eurasia. Additionally, it achieves SIL 2 (TÜV) functional‑safety certification, confirming reliability for use within Safety Instrumented Systems (SIS) protecting human life and critical assets. These credentials guarantee that the detector meets rigorous electrical, mechanical, and optical safety standards for explosive or toxic atmospheres. Engineers responsible for process safety management can integrate the 936 into plant alarm networks or distributed control systems with assured compliance. Its standard 24 VDC supply (18–32 VDC range) simplifies international compatibility between grid formats and renewable energy supplies. Verification tests include electromagnetic compatibility, vibration endurance, and drift evaluation (±5 % of full scale long‑term). The entire sensor assembly ships with calibration records traceable through Emerson’s ISO‑certified production facilities, simplifying audits and validation checks required under IEC 61508 and CSA regulations. These accumulated global approvals empower operating companies across energy, petrochemical, and manufacturing sectors to implement the Rosemount 936 confidently, knowing every reading aligns with the highest international standards for toxic‑gas safety instrumentation.

Dedicated Applications Across Oil, Gas, and Industrial Sectors

The Rosemount 936 excels across a broad range of industrial applications requiring reliable, long‑range toxic‑gas monitoring. In oil and gas production zones, it identifies hydrogen sulfide leaks occurring around wellheads, separators, and compressor stations, alerting crews before concentrations reach dangerous thresholds. In petrochemical plants, it safeguards workers against accidental ammonia emissions during refrigeration, neutralization, and synthesis processes. Chemical manufacturers depend on its stability around blending tanks and storage yards, where small leaks can become hazardous under high humidity. Within wastewater and biogas facilities, the detector provides protection near anaerobic digestion tanks and sludge handling units prone to intermittent H₂S release. Mining operations employ the 936 to monitor ventilation shafts where sulfur contamination threatens underground personnel. Food and fertilizer factories benefit from its UV detection accuracy to manage ammonia vapor escaping from cooling or fermentation systems. Even transportation terminals and loading docks use the device to maintain clean air compliance standards. The detector’s wide operating temperature and immunity against fog or vibration make it universally adaptable across harsh terrains—from offshore platforms to desert gas processing plants. By facilitating continuous perimeter surveillance, the Rosemount 936 advances occupational health protection and environmental responsibility in diverse industrial infrastructures worldwide.

Intelligent Diagnostics Strengthen Preventive Safety Architecture

Emerson equips the Rosemount 936 with internal diagnostic analytics that continuously assess detector alignment, optical cleanliness, and electronic health. The system’s real‑time diagnostic module verifies component performance, automatically recording anomalies in a built‑in data logger capable of storing up to 100 events. Operators receive immediate feedback for preventive maintenance before faults can influence detection accuracy. Such intelligent oversight drastically minimizes downtime, aligning with predictive maintenance strategies across smart plants and refineries. Combined with the detector’s factory calibration for hydrogen sulfide and ammonia, this intelligence stabilizes long‑term sensitivity and reduces cross‑interference from nearby gases or environmental radiation. The 936 achieves remarkable false‑alarm immunity—not affected by sunlight, hydrocarbon flames, or radiative noise—ensuring pure analytical focus on target toxins. Maintenance crews can access drift and quality metrics during inspection without removing the sensor from service, preserving continuous monitoring. Emerson’s digital approach harmonizes with Industry 4.0 paradigms, allowing integration through legacy Modbus RTU or new Ethernet structures for centralized plant analytics. Altogether, the diagnostic architecture transforms the Rosemount 936 into a smart guardian that communicates performance transparency, securing worker confidence and reducing maintenance costs for large‑scale installations worldwide.

Operational Advantages Provide Accuracy and Fast Response

Speed of detection is critical when protecting life and property from toxic‑gas exposure. The Rosemount 936 responds within three seconds (T90 ≤ 3 s), enabling immediate alarm activation for evacuation or neutralization protocols. Its sensitivity range spans 0 to 500 ppm·m, converting cumulative path concentration into actionable process signals readable by control systems. The open‑path configuration enhances volumetric detection—covering thousands of cubic feet versus limited point sensors—allowing comprehensive monitoring along tanks, pipelines, or open service corridors. Its calibrated UV absorption profile ensures precise distinction between H₂S and NH₃ spectral signatures, minimizing cross‑sensitivity against hydrocarbons and other volatiles. The internal optical heater instantly restores functionality during condensation events, eliminating signal artifacts and unproductive downtime. Moreover, displacement tolerance (± 1°) supports alignment stability despite building vibration, critical for offshore and heavy industrial plants. Emerson’s three‑year warranty coupled with mechanical resilience provides lasting dependability for both permanent installations and mobile safety units. Fast responsiveness, exceptional precision, and operational freedom define how the Rosemount 936 extends advanced toxic‑gas safety into complex field settings—becoming an essential cornerstone for integrated environmental monitoring networks across modern industrial ecosystems.