Honeywell FS-TSGAS Series Flame Detectors – FS-TSGAS-1624

Technical Dossier

Product Details And Specifications

Honeywell FS-TSGAS Series Technical Notes

The Evolution of FS-TSGAS Architecture

The FS-TSGAS platform evolved from Honeywell's earlier Searchline Excel open-path detector family, which established the dual-beam IR measurement principle in the 1990s. The original Searchline Excel (SXCEL) series used a single-wavelength active IR source with a retroreflector configuration, limiting path lengths and requiring frequent optical alignment. The FS-TSGAS generation introduced a dedicated transmitter-receiver topology, eliminating retroreflector dependency and extending reliable detection paths to 200 m in industrial atmospheres with moderate particulate loading.

Subsequent firmware revisions added HART 7 digital communication overlay on the 4–20 mA loop, enabling remote diagnostics, beam alignment status, and gas concentration trending without breaking the hardwired safety loop. The introduction of the FS-TSGAS-1624 variant standardized the 16–24 VDC supply range, broadening compatibility with both 24 VDC instrument buses and battery-backed UPS systems common in offshore installations. Later variants incorporated enhanced EMC shielding to meet IEC 61000-4 immunity levels required by European ATEX Directive 2014/34/EU.

As the series has entered its mature lifecycle phase, Honeywell has transitioned new project specifications toward the Searchline Excel Plus and Midas platform families. However, the FS-TSGAS series remains the dominant installed base in brownfield sites, and long-term maintenance support — including spare transmitter/receiver heads, junction boxes, and alignment tools — remains a critical procurement requirement for plant integrity teams.

FS-TSGAS Full Catalog & Functionalities (SKU List)

The following SKUs represent the verified FS-TSGAS series product range, classified by functional role within the open-path gas detection system:

Transmitter / Receiver Units

• FS-TSGAS-1624: Open-path IR gas detector, 16–24 VDC, 4–20 mA + relay output, SIL 2
• FS-TSGAS-1624H: FS-TSGAS-1624 with integrated HART 7 communication overlay
• FS-TSGAS-2430: Open-path IR gas detector, 24–30 VDC supply variant for high-voltage instrument buses
• FS-TSGAS-TX: Standalone IR transmitter head, field-replaceable, path length up to 200 m
• FS-TSGAS-RX: Standalone IR receiver head, field-replaceable, matched to FS-TSGAS-TX
• FS-TSGAS-TXRX-KIT: Matched transmitter/receiver replacement kit with alignment jig and calibration certificate

Junction Boxes & Enclosures

• FS-TSGAS-JB-SS: 316L stainless steel junction box, IP66/67, ATEX Zone 1 rated, for transmitter wiring termination
• FS-TSGAS-JB-GRP: GRP (glass-reinforced polyester) junction box, IP65, Zone 2, lightweight offshore variant
• FS-TSGAS-MOUNT-ADJ: Adjustable stainless steel mounting bracket, ±15° pan/tilt, for beam alignment on structural steelwork

Power Supply & Signal Conditioning

• FS-TSGAS-PSU-24: Dedicated 24 VDC DIN-rail power supply module, 2 A, short-circuit protected, for FS-TSGAS loop power
• FS-TSGAS-ISO-4-20: 4–20 mA loop isolator/repeater, galvanic isolation 1500 V, for long cable runs to DCS marshalling

Calibration & Maintenance Accessories

• FS-TSGAS-CAL-GAS: Certified methane/nitrogen calibration gas cylinder, 2.5% v/v CH4, for span verification
• FS-TSGAS-ALIGN-KIT: Optical alignment tool set including laser pointer adapter and target card for initial commissioning
• FS-TSGAS-WINDOW-KIT: Replacement optical window set (transmitter + receiver), anti-scratch coated borosilicate glass

Communication & Integration

• FS-TSGAS-HART-MODEM: USB HART modem for laptop-based configuration and diagnostics of HART-enabled FS-TSGAS units
• FS-TSGAS-RS485-CONV: RS-485 to Modbus RTU converter module for legacy DCS integration without HART infrastructure

Quality Control for the FS-TSGAS Range

The FS-TSGAS series presents specific quality verification challenges due to its optical measurement principle and safety-rated analog output. DriveKNMS applies the following test protocol to all FS-TSGAS units prior to dispatch:

• Optical path integrity check: IR source output power measured against OEM specification using calibrated optical power meter; receiver sensitivity verified at minimum and maximum path lengths.
• 4–20 mA output linearity test: Loop current verified at 0%, 20%, 40%, 60%, 80%, and 100% LEL gas concentration equivalents using certified calibration gas mixtures; deviation must be within ±0.5% of full scale.
• Relay output functional test: Alarm relay actuation verified at configured threshold levels (typically 20% LEL and 60% LEL); contact resistance measured to confirm no oxidation on gold-plated contacts.
• HART communication verification (HART-enabled units): Device descriptor, PV, SV, TV, and QV variables polled via HART modem; configuration parameters compared against factory default baseline.
• Enclosure integrity inspection: Cable gland threads, conduit entries, and optical window seals inspected for mechanical damage, corrosion, and seal degradation; IP66 rating re-verified by visual inspection protocol.
• EMC pre-compliance check: Unit powered in shielded test enclosure; conducted emissions on supply lines measured to confirm no anomalous noise indicative of internal PCB damage.