Capteur de gaz dangereux Bently Nevada 350800-01-180-00

Description

The Bently Nevada 350800-01-180-00 is a high-performance Hazardous Gas Sensor designed for use within the 3500/63 Hazardous Gas Detection System. This continuous-diffusion catalytic bead sensor provides critical machinery and personnel protection by continuously monitoring areas for combustible gases, specifically focusing on methane (CH4) and hydrogen (H2).

The sensor operates via a matched pair of catalytic and reference beads that form a Wheatstone bridge configuration when interfaced with the 3500/63 monitor module. The catalytic bead is coated with a premium oxidization-promoting catalyst, while the reference bead is specially treated to inhibit oxidization. When combustible gas comes into contact with the sensing surface, the electrical current supplied by the monitor heats the beads, initiating localized oxidation at the catalytic bead. This chemical reaction increases the temperature and internal resistance of the active bead relative to the reference bead, unbalancing the Wheatstone bridge proportionally to the concentration of the target combustible gas up to 100% LEL.

Engineered for extreme reliability, the Bently Nevada 350800-01-180-00 can be threaded directly into standard structural conduit lines or integrated into a dedicated flameproof junction box enclosure to optimize routing and simplify field wiring terminations. The sensor configuration requires a continuous constant current of 300 mA from an external power source regulated directly through the 3500/63 monitor and input/output (I/O) module array.

Features

• Dual-Bead Wheatstone Bridge Configuration: Combines an active catalytic bead and an oxidation-inhibited reference bead for precise differential tracking.
• Dedicated Gas Target Detection: High sensitivity and specific tuning for methane (CH4) and hydrogen (H2) explosive limits.
• Extended Dynamic Temperature Window: Certified for continuous operational stability in ambient temperature profiles extending from -40 Celsius to 200 Celsius.
• Flexible Installation Profile: Supports standard industrial conduit direct threading or flameproof enclosure integration for rapid swap field cycles.
• Extended Life Horizon: Robust physical construction delivering a minimum operational service window of 2 years and a typical lifecycle up to 5 years under standard operating environments.

Applications

• Turbine Enclosure Combustible Gas Monitoring
• Hydrogen-Cooled Generator Seal Oil Systems
• Oil and Gas Hydrocarbon Processing Facilities
• Chemical and Petrochemical Manufacturing Areas
• Compressed Gas Storage and Distribution Facilities
• Compressor Station Gas Infrastructure

Ordering Information

• 350800: Hazardous Gas Sensor.
• 01: 180 Inch Lead.
• 180: 180 Inch Lead.
• 00: None Housing Option.

Technical Specifications

Connections/Interfaces

Installation Guidelines

• Wiring Configurations: Always confirm field wire mapping and continuity metrics across all termination blocks prior to powering on the system. Never short any structural active sensor leads directly to the localized system earth ground plane.
• Lead Cable Optimization: Do not under any circumstances allow extra loop coiling of excess lead length sections inside the sensor junction box or flameproof enclosure spaces. Field engineers must trim and strip all lead paths down to the true required functional run distance.
• Hot Swap Sequence: When performing live maintenance or physical replacement of a sensor under active system rack power, ensure the immediate workspace environment is clear of hazardous gas concentrations. During physical removal, disconnect the black reference line last. When engaging the new terminal interface, connect the black lead first.
• Environmental Degradation Elements: Prevent direct physical contact or exposure of the catalytic bead faces to chemical agents or cross-contaminating substances including silicone-based RTV formulations, wet paints, and surrounding welding plume exhaust vapors.
• Moisture Exposure Mitigation: Position the face assembly away from locations susceptible to high condensation pools or streaming liquid washdown vectors to prevent water block entry at the sensor diffusion plate.
• Orientation and Flow Mechanics: If installing sensors within structural ventilation paths, ductways, or localized force-draft streams, verify that the active sensing window faces directly into the primary airflow currents.

Compliance and Certifications

• ATEX / IECEx Zone 1 Protection: II 2G Ex d IIB+H2 T2 (Flameproof protection classification certified for Zone 1 locations, permissible for methane and hydrogen environments with a maximum temperature class threshold ≤ 300 Celsius).
• North American Class 1 Div 1 / Zone 1 Standards: Class 1, Zone 1, AEx d IIB+H2 T2 (FM 3021960 certified for operation across an ambient window of -40 Celsius ≤ Ta ≤ 200 Celsius).

FAQ

What gases can be detected with the 350800 sensor?

The sensor is designed specifically to detect methane and hydrogen gas concentrations up to their lower explosive limits.

What is the length of the lead wire provided with this model?

This model comes with a factory-integrated 180-inch lead wire.

What is the minimum warm-up timeline required before attempting a field calibration?

The sensor must be powered continuously via the monitoring system for at least 30 minutes to stabilize before beginning calibration.

What happens if the internal sensitivity of the sensor falls below 6 mV/% LEL?

The sensor will fail system verification checks and cannot be calibrated, indicating it is spent or poisoned.

Can the excess lead wire be coiled inside the housing?

No, coiling excess lead wire inside junction boxes can cause interference and is prohibited; leads must be cut to the required installation length.

What is the maximum operating temperature limit for this sensor head?

The sensor is rated for reliable continuous operation in extreme environments up to 200 Celsius.

What is the primary operational mechanism behind the sensor?

It uses a matched catalytic and reference bead Wheatstone bridge circuit that detects the temperature variance caused by gas oxidation.

How often does the monitoring system require recalibration of the sensor channels?

The hazardous gas channel and sensor combination must be calibrated at minimum every 90 days to comply with safety compliance.

What are the primary chemical poisons that damage the catalytic element?

Silicone-based RTV compounds, chlorinated hydrocarbons, metal hydrides, and heavy hydrocarbon vapors will poison or reduce bead sensitivity.

What calibration flow rate is required when performing a manual calibration?

A regulated flow rate of 0.5 liters per minute must be maintained during a standard manual calibration cycle.

Does this specific model include a flameproof housing enclosure?

No, the option suffix indicates it is supplied without a housing, allowing direct integration into conduit networks.

What is the expected life expectancy of the sensor in standard industrial service?

The sensor provides a minimum life of 2 years, with an average service lifecycle reaching up to 5 years under normal conditions.

What color-coding standard is utilized for field terminal connection wiring?

The sensor connections use a 3-wire format consisting of a White wire for return, a Red wire for excitation, and a Black wire for constant current.

Can this sensor be deployed in Zone 1 locations?

Yes, the sensor is certified flameproof with ATEX/IEC markings for safe installation inside Zone 1 hazardous environments.