Honeywell 2104B2081 Searchline Excel Open-Path Infrared Gas Transmitter

Honeywell 2104B2081 Searchline Excel Transmitter

Configured for combustible gas detection in hazardous industrial areas, the Honeywell 2104B2081 (2104B2081 Searchline Excel Transmitter) provides direct physical/electrical execution for open-path monitoring.

Hardware Specifications

4-20 mA HART Loop Protocol & Channel-to-Channel Isolation

The 2104B2081 transmitter utilizes the 4-20 mA HART loop protocol to transmit real-time gas concentration data to the host control system. The internal circuitry provides galvanic isolation between the detector electronics and the output loop, mitigating potential ground loop interference in large-scale hazardous area installations. This isolation ensures that the signal remains stable and immune to common-mode noise, maintaining high data fidelity during the detection of combustible hydrocarbon clouds. Furthermore, the unit features integrated weather compensation and optics heating, which maintains accurate baseline absorption values and prevents signal degradation due to environmental condensation or icing.

Frequently Asked Questions

Q: How is the transmitter calibrated to ensure sensitivity across the 120 m range?

A: Calibration is performed using test gas cells placed over the receiver/transmitter optics. The system utilizes internal diagnostics to verify beam strength and signal-to-noise ratios, automatically compensating for beam attenuation caused by alignment shifts or partial blockages.

Q: Does the transmitter require periodic maintenance for the heated optics?

A: While the optics heating system minimizes ice and dew formation, periodic cleaning of the exterior lenses with non-abrasive materials is required to ensure optimal infrared transmission. Internal diagnostics will signal a "beam block" or "low signal" fault if dust accumulation significantly reduces beam intensity.

Field Installation Guidelines

• Mounting Stability: Install the transmitter on a rigid, vibration-resistant structure to maintain beam alignment with the receiver over the 120 m range. Ensure that the 316 stainless steel housing is properly bonded to the local structural earth.
• Beam Path Clearance: Maintain a clear line-of-sight between the transmitter and receiver. Ensure no moving machinery or high-traffic areas pass through the infrared beam, as intermittent obstacles can trigger false gas alarms or "beam block" diagnostic faults.
• Electrical Connection: Use armored cable or conduit compliant with local hazardous area regulations (e.g., ATEX requirements). Terminate the shield at the control room end to prevent ground loop currents, while ensuring the transmitter housing is adequately grounded for surge protection.
• Weather Considerations: Position the units to minimize direct exposure to persistent water spray or snow buildup. Utilize provided weather shields if the installation site experiences extreme precipitation, which can affect the infrared signal path.