FS20X Flame Detector

Overview

Elevate your gas detectors’ potential with Honeywell's expert maintenance services! Maximize uptime, eliminate costs, and ensure on-time, on-budget project completion.

Key features

Patented* WideBand IR™ Infrared combined with Ultraviolet
Detection range greater than 200 feet to 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

Applications

Confined space entry
Oil, gas and petrochemical
Wastewater and sewage
Steel and chemical plants

Standards and certification

Supplier: ISO 9001:2015 certified

PRODUCT DATASHEETDoc. SSLS/DS/GD-019 · Rev. 01 · 13-Oct-2026

FS20X Flame Detector – technical data

Technical specifications

Brand	Honeywell
Warranty	3 Years from Date of Shipment
Alarm Included	Yes
Features	Arc Welding Immunity
Relay Included	Yes
Wireless Technology	WideBand IR™
Visual Indicators	Green LED: Power / Red LED: Alarm / Yellow: Fault
Vibration	Meets or Exceeds MIL Spec 810C Method 514.2, Curve AW12
Mounting Hole Diameter	0.25
Output Signal Range	4 to 20 mA
Humidity Range	5 to 98% RH (Non-Condensing)
Altitude Range	200ft (60m)
Analog Output Signal Type	mA
Number of Digital Communication Ports	2
Relay Rated Load	1A @24V DC
Relay Output Configuration	Auxiliary: SPDT (NO/NC) / Fault: SPST (NO) / Fire Alarm: SPDT (NO/NC)
Relay Activation Settings	Relay 1: Fire Alarm / Relay 2: Fault / Relay 3: Auxiliary
Sensing Method	IR, UV
Maximum Analog Input Resistance	400
Plug Type	10 pin for J2 Connector / 6 pin for J1 Connector
Output Signal Type	mA
Number of Relay Outputs	3
Mounting	Swivel Bracket Assembly
Default Relay Activation	Alarm Relay (Relay 1), Auxiliary Relay V (Relay 2), Fault Relay (Relay 3)
Wiring	Shielded: 2.5 sq.mm (14 AWG) to 0.326 sq.mm (22 AWG)

PRODUCT DATASHEETDoc. SSLS/DS/GD-019 · Rev. 01 · 13-Oct-2026

FS20X Flame Detector – technical data, continued

Technical specifications

Spectral Sensitivity	Near Band IR: 0.7 to 1.1 microns / Ultraviolet: 185 to 260 Nanometers / Visible: 400 to 700 Nanometers / Wide Band IR: 1.1 to 3.5 Microns
Sensitivity	Very High, High, Medium, Low
Loop Resistance	50 to 400 Ohms
Field of View	90° Full 100% Core of Vision / ± 45° From On Axis
Conduit Entries	(2) 3/4 in NPT
Communication	FireBus II / ModBus Protocol / RS485

Ordering information

Brand	Honeywell

Inspection and care

Keep sensors and filters clean, charge batteries as directed and record bump tests and calibrations.

Storage

Store in a cool, dry place away from direct sunlight, heat and chemicals.

Data given in good faith from manufacturer information and subject to change without notice. Select PPE based on a site risk assessment. Scan the code for the product page.