Description

The Honeywell 2106B2312 is a high-temperature (HT), explosion-proof catalytic bead gas detector from the Sensepoint product family. It is specifically designed for continuous monitoring of combustible gases (Lower Explosive Limit / LEL) in hazardous industrial environments subject to sustained operational temperatures up to 150°C (302°F), such as gas turbine enclosures, processing ovens, and high-heat manufacturing areas.

Commercial Availability & Procurement

• Condition: New Original (Factory Sealed)
• Warranty: 12-Month Industrial Warranty
• Lead Time: Typically ships within 1–3 business days from safety instrumentation stock.
• Pricing Note: Listed price is indicative of standalone hardware. Contact our components desk for current pricing, bulk discounts, or combined transmitter packages.

Technical Specifications

Field Experience & Engineering Insights

The “2312” vs “2310” Suffix (Thread Sizing)

The distinction within the Honeywell Sensepoint High-Temperature numbering convention defines the physical entry thread. While the 2106B2310 configuration uses a metric M20 entry, the 2106B2312 uses a standard North American 3/4″ NPT thread profile.

• Direct Fitting: This eliminates the need for separate thread conversion adapters when attaching the sensor directly into rigid heavy-wall NPT conduit hubs or explosion-proof junction boxes.
• Explosion-Proof Integrity: Ensure at least 5 full threads are engaged and torqued down during mounting to preserve the explosion-proof flame-path seal.

High-Temperature Catalytic Bead Architecture

The sensor features a carefully matched pair of pellistor beads (one active, one reference) operating in a standard Wheatstone bridge setup.

• Combustion Requirement: Catalytic bead sensors require a baseline level of atmospheric Oxygen (O_2) to successfully oxidize the target gas on the active bead. Do not mount this unit in pure inert gas zones (e.g., nitrogen-blanketed tanks), as the lack of oxygen will prevent the combustion reaction, causing the sensor to output a false-safe 0% LEL reading.
• Mounting Orientation: Always mount the sensor assembly pointing vertically downward. This limits the risk of airborne dust, particulates, or piping condensation blanketing the internal sintered flame arrestor mesh, which would slow gas diffusion time (T_{90}).

Calibration and System Integration

• 3-Wire Architecture: Connects as a standard constant-current bridge circuit (typically driven at roughly 200mA). It interfaces with centralized gas monitoring panels (like the Honeywell Touchpoint series) or generic industrial transmitter modules capable of handling millivolt-bridge inputs.
• Cross-Sensitivity Factors: The sensor is factory-calibrated using Methane. If your facility is monitoring alternate heavy hydrocarbons or specialized solvents, you must apply the designated Honeywell cross-sensitivity correction factors at the control interface to guarantee accurate LEL scaling.

System Integration & Compatibility Checklist

• Wiring Cable: High-temperature rated cabling is strictly required if the junction box is positioned inside the high-heat zone.
• Accessories: Compatible with Honeywell weather protection caps, collecting cones (for light gases like Methane or Hydrogen), and flow-through sampling adapters.
• Hazardous Environments: Certified for ATEX Zone 1/2 environments. Ensure the chosen junction box matches or exceeds the local classification profile.

Frequently Asked Questions

What should I check if the gas control panel registers a “Sensor Open Circuit” fault?

Isolate the power supply to the loop and measure the electrical resistance across the sensor pins at the terminal strip using a digital multimeter. Test the resistance from the common line to the active and reference leads respectively. An infinite reading (OL) demonstrates that the micro-fine platinum wire coil inside one of the pellistor beads has broken due to extreme structural vibration, extreme thermal shock, or old age, necessitating a full replacement of the sensor head.

How often does the 2106B2312 require routine span calibration?

Honeywell suggests performing a calibration check or bump test every 3 to 6 months under standard operating conditions. High-temperature environments can sometimes accelerate baseline zero-drift or expose the sensor to airborne contaminants (such as silicones or sulfur compounds), making regular field span validation essential to ensure response accuracy.

Can I unscrew this sensor head while the turbine core is actively operating?

Only if the environment has been verified as completely safe and gas-free via a hot-work permit, or if the main power to the gas detection loop is isolated. Disconnecting live electrical terminals within a Zone 1 classified explosive atmosphere introduces a risk of an electrical arc flash, which can ignite present flammable vapors.