SIMRAD Optronics GD10 Infrared Gas Detector

SIMRAD Optronics GD10 Infrared Gas Detector

The SIMRAD Optronics GD10 (and its direct evolution series, GD10P/GD10PE) is an explosion-proof, point-type infrared gas detector engineered for continuous monitoring of combustible hydrocarbon gas concentrations in extreme offshore, marine, and onshore industrial environments. Built on non-dispersive infrared (NDIR) absorption with dual-beam, dual-wavelength solid-state optical technology, the GD10 eliminates the common points of failure associated with older filament lamps and catalytic pellistor beads.

Unlike catalytic sensors, the GD10 does not rely on the presence of oxygen to take accurate measurements and is completely immune to sensor poisoning from silicones, sulfides, and hydrogen sulfide. The optomechanical core uses an ultra-stable, solid-state silicon IR source pulsing at 32 Hz, coupled with internal optical path compensation. This design delivers exceptional signal stability, eliminating routine zero and span field recalibrations throughout the operational life of the unit.

Model Details

• Base Series: SIMRAD Optronics GD10 / GD10P / GD10PE
• Standard Manufacturing Part Numbers (MPN):
  • GD10-P00-01 (Standard point hydrocarbon, 0–100% LEL Methane, 5s response, 4–20 mA current source)
  • GD10-P00-02 (Fast response 1s, 0–100% LEL Methane)
  • GD10-P00-03 (Propane calibrated 0–100% LEL, standard optics)
  • GD10-PE0-01 (Extended path length / high sensitivity for ventilation duct monitoring, trip levels down to 4% LEL)
  • GD10-P00-CO2 (Dedicated Carbon Dioxide IR absorption cell)

Key Features

1. Poison-Proof Solid-State NDIR Optics: Uses solid-state silicon semiconductor IR emitters (SimSource™) rather than heated incandescent filaments, resisting mechanical shock, extreme vibration, and sensor burn-out.
2. True Dual-Wavelength / Dual-Path Architecture: Continuous reference-beam optical compensation monitors mirror/lens cleanliness in real time, preventing false alarms caused by airborne salt spray, water, or oil mist.
3. Zero Routine Field Recalibration: Factory-calibrated optical bench maintains baseline stability within ±5% full scale over the lifetime of the sensor, reducing operational servicing expenses.
4. Severe Environment Enclosure: Marine-grade ASTM 316 / SIS 2343 stainless steel housing with independent heated optics prevents condensation, icing, and corrosion in Class 1 Zone 1 / Div 1 locations.

Technical Details

Equipment Compatibility & Control System Integration

• Autronica Systems: Compatible with AutroSafe IFD, Autroprime, and BX-10 interfaces.
• Kongsberg Maritime: Directly interfaced with Kongsberg K-Safe, K-Chief Marine Automation, and standard discrete analog input racks.
• Honeywell & Yokogawa DCS: Honeywell Experion Process Knowledge System (PKS), Safety Manager (SM), FSC, Yokogawa ProSafe-RS.
• Rockwell / Emerson: Allen-Bradley GuardLogix, Trusted TMR, Emerson DeltaV SIS, and Rosemount 3490 series controllers.
• Legacy Catalytic Bridge Upgrades: Compatible via an optional 3-to-4 wire catalytic bridge converter module, permitting direct drop-in replacement on legacy catalytic control cards without pulling new field cabling.

Marine Engineering Expert’s Guide

1) Optical Condensation & Heating Circuit Integrity

While the GD10 features internally heated optical mirrors and lenses, mounting orientation is critical. Always install the unit horizontally with the weather protection hood sloping downward. This allows rain, deck washdown, and condensing moisture to run off freely without pooling in the optical measuring chamber. Never mount the sensor with the beam path pointing straight up.

2) Cable Gland Torquing & Terminal Sealing

The terminal enclosure is rated Ex e (Increased Safety). Ensure you use an approved M20 Ex e brass or stainless steel barrier gland. Do not rely on tape for thread sealing; always fit the silicone/fiber sealing washer. If condensation is common in your field conduit or marine cable trays, make sure to form a drip loop directly beneath the M20 entry to prevent water ingress along the cable jacket.

3) Decoupling Diagnostic Current Signals

Modern DCS safety cards monitor for open circuits below 3.6 mA. Because the GD10 steps its analog output down to 1.0 mA (dirty optics) and 2.0 mA (early warning obscuration), ensure your safety PLC analog channel is programmed with discrete threshold bands rather than a flat low-current trip. Mapping 1.0 mA and 2.0 mA to a preventative maintenance alarm rather than an emergency shutdown prevents costly nuisance shutdowns while keeping safety interlocks active.

Frequently Asked Questions

What is the main difference between catalytic gas detectors and the SIMRAD GD10 infrared detector?

Catalytic gas detectors depend on an active chemical reaction requiring ambient oxygen, and they are susceptible to poisoning by compounds such as siloxanes and hydrogen sulfide H2S. The SIMRAD GD10 uses optical non-dispersive infrared absorption, which functions reliably in oxygen-depleted or inert environments and is immune to chemical sensor poisoning.

Does the SIMRAD GD10 require regular zero and span span calibration?

No. Because the GD10 uses solid-state silicon infrared emitters and an active dual-wavelength compensating beam system, the optical bench is factory-set and does not experience drift from filament degradation. Periodic functional bump testing is recommended to confirm optical path clearance, but regular zero and span adjustment is unnecessary.

What output signals does the GD10 produce during optical blockage or fault conditions?

Under normal operation without gas, the transmitter outputs 4.0 mA. If the optics become partially obscured by dirt, salt, or snow, it outputs 2.0 mA (early clean warning). If optical attenuation reaches 70%, it outputs 1.0 mA. A hardware or fatal system fault causes the output to drop to 0.0 mA.

What is the advantage of the GD10PE model compared to the standard GD10P?

The GD10PE model features an extended optical path length, providing higher measurement sensitivity. This makes it suited for high-velocity air intakes, ventilation ducts, and turbine exhausts where rapid dispersion dilutes gas concentrations and requires trip settings as low as 4% to 10% LEL.