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Sieger Fire Sentry FS20X Fire and Flame Detector

The Fire Sentry FS20X is the latest generation high technology Multi-Spectrum (UV/Dual IR/VIS) Fire and Flame Detector, which is part of the FSX family of advanced technology Electro-Optical Flame detectors.

Based on the foundation of the highly successful and reliable Fire Sentry SS4 detector, the Fire Sentry FS20X detector represents a quantum leap in integrating Infrared and Ultraviolet sensing technologies.

The Fire Sentry FS20X is a Multi-Spectrum and UV/Dual IR/VIS fire and flame detector with a proven UV solar-blind sensor. The Fire Sentry FS20X exhibits faster false-alarm free response to fires over a wider temperature range and with a much longer detection range compared to conventional UV/IR detectors.

Conventional and older technology UV/IR detectors, using narrow band 4.3 micron IR sensors, will not respond to smoky fires or if the detector lens is contaminated with oil and other substances since both UV and 4.3 micron signals are attenuated, obscured or absorbed by thick smoke or detector lens contaminations. Also, these old technology UV/ IR detectors will not alarm to any fire if they are installed behind ordinary window glass.

The Fire Sentry FS20X detector using advanced patented algorithms for signal processing and fire and flame analysis is designed to alarm to all types of fires in all industrial environmental conditions. If the detector's UV signal is degraded due to heavy smoke or a contaminated lens, the Fire Sentry FS20X's patented* WideBand IR™, Near Band IR and Visible sensors will still alarm to fire, albeit at a reduced sensitivity and slower response time.

Dual microprocessors provide a high level of fail-safe operation combined with fast and reliable performance. The master microprocessor performs high-speed digital sampling and signal processing calculations whilst the slave microprocessor handles various sensor data, performs communications, self-diagnostics and provides interface versatility and additional memory for storing event log and FirePic™ data.

The Fire Sentry FS20X detector has a detection range in excess of 60 m (200 feet) (very high sensitivity setting) for the detection of a 0.1m2 (one square-foot) Heptane reference fire and has a cone of vision greater in volumetric coverage than most UV/IR detectors. This means fewer detectors can be used as compared to other manufacturers' detectors.

Data Sheet
Application Chart
Fixed-Point Industrial Fire and Gas Detection Brochure
Fire and Gas Detection for the Petrochemical Industry Brochure
Fire Sentry Accessories Brochure
Fire Sentry Controllers Brochure
Fire Sentry FS20X Specifications
MODEL FS19X & FS20X Series Manual


  Patented* WideBand IR™ Infrared combined with Ultraviolet
  Detection range greater than 60 m (200 feet) to 0.1 m2 (1 sq. ft.) heptane fire
  Patented* Electronic Frequency Analysis
  Visible sensor for optimum false alarm rejection
  Selectable detection sensitivities
  Solar blind 90° full 100% cone-of-vision
  Dual microprocessors for reliable performance
  Real-time clock for accurate time dating of events
  FirePic™ - Up to 6 pre-fire event data storage
  Event log - Up to 200 events with date and time stamp
  Built-in RS-485 ModBus communication
  Built-in non-isolated 4-20 mA analog output (sink or source)
  Alarm, Fault and Fire Verification relays
  Automatic Optical Path and Electronic self-test
  Wide operating temperature range
  Patented* Electronics Module for component protection with plug-in terminations for easy field installation
  Two 25 mm conduit entries or two ¾" NPT
  Low power consumption
  High RFI and EMI immunity
  FM approved
  Ex d ATEX approved
  Meets SIL 2 requirements


  Detects hydrocarbon and non-hydrocarbon fuel fires in all environmental conditions
  Arc welding immunity
  False alarm rejection for environmental conditions
  Minimal maintenance for trouble-free operation
  PC software and interface module (FSIM) for fault diagnostics real-time graphs (RTGs), and downloading of FirePics™ and event log
  Suitable for a wide variety of applications


  Refineries and oil production facilities
  Off-Shore platforms
  Turbine/Compressor enclosures
  Acetylene processing and storage
  Oil and Gas pipelines and pumping stations
  LNG/LPG loading and unloading facilities
  Natural Gas and CNG plants
  Ethanol, Methanol, and IPA production and storage
  Crude oil and gasoline storage and tank farms
  Aircraft hangars
  Hydrogen plants and storage
  Paint and solvent storage
  Chemical production, storage, and loading facilities
  Power plants
  Silane gas storage

Ordering Information

FS20X-211 Series, standard temp range -40° to 85°C

FS20X-211-21-2 DUAL IR/UV FLAME DETECTOR Copper-Free Aluminum Encl. with (2) ¾" NPT entries, FM, cFM for Class I, Division 1, Groups A, B, C, D; Class II, Division 1, Groups E, F, G; Class III
FS20X-211-22-2 DUAL IR/UV FLAME DETECTOR Stainless Steel Encl. with (2) ¾"NPT entries, FM, cFM for Class I, Division 1, Groups A, B, C, D; Class II, Division 1, Groups E, F, G; Class III
FS20X-211-23-3 DUAL IR/UV FLAME DETECTOR Copper-Free Aluminum Encl. with (2) M25 entries, FM, cFM, ATEX, IECEx for Class I, Zone 1
FS20X-211-24-3 DUAL IR/UV FLAME DETECTOR Stainless Steel Encl. with (2) M25 entries, FM, cFM, ATEX, IECEx for Class I, Zone 1

Please note - Product designs and specifications are subject to change without notice. The user is responsible for determining the suitability of this product.

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