UV/IR Flame Detector 3600-LB

Sierra Monitor’s 3600-LB flame detector monitors hydrocarbon-based fuel and gas fires, hydroxyl and hydrogen fires, as well as metal and inorganic fires.

UV/IR Flame Detector 3600-LB

The 3600-LB uses a combination of ultraviolet (UV) and infrared(IR) sensor technology. The UV/IR flame detector senses radiant energy in the short wave sections of both the ultraviolet and infrared portions of the electromagnetic spectrum. The signals from both sensors are analyzed for frequency, intensity, and duration. Simultaneous detection of radiant energy in both the UV and IR sensors triggers an alarm signal.

With the UV/IR Dual Sensor, the 3600-LB can better recognize different types of flame signatures, leading to fewer false alarms. In addition, the UV sensor incorporates a special logic circuit that helps prevent false alarms caused by solar radiation. The 3600-LB also has a response time as fast as 150 milliseconds. Other features include a heated window to eliminate condensation and icing, HART and Modbus capabilities for digital communications, low power requirements, and a compact design.

The UV/IR Flame Detector 3600-LB is approved and certified by a variety of third party agencies, including FM, ATEX, IECEx, TUV, and CSA. These approvals and certifications assure our customers that we carry only the highest quality of products and performance.

Uv/ir flame detector
1. UV/IR Dual-Sensor

Simultaneously detect UV and IR signatures for maximum accuracy and reliability

2. High-Speed Response

Detect flames with speeds as fast as 150 milliseconds

3. Heated Window

Eliminate any possible condensation or icing to ensure the detector to function properly

4. Low Power Requirements

Save energy costs while protecting the facility

5. Multiple Output Options (Relay Outputs, 0-20 mA, HART, Modbus RS-485)

Easily install in a variety of field applications and easily obtain critical safety information wherever needed with maximum flexibility and compatibility

Model Number


Spectral Response


UV: 0.185 - 0.260 micron

IR: 2.5 - 3.0 micron


UV:0.185 - 0.260 micron

IR: 4.4 - 4.6 micron

Detection Range

(At highest Sensitivity Setting for 1 sq. ft. / 0.1 sq. m pan fire)

215 ft. (65 m) n-Heptane
50 ft. (15 m) n-Heptane
50 ft. (15 m) Gasoline
37 ft. (11 m) Diesel Fuel
37 ft. (1 m) JP5
16 ft. (5 m) Hydrogen**
37 ft. (11 m) Kerosene
25 ft. (7.5 m Ethanol 95%
25 ft. (7.5 m Methanol
25 ft. (7.5 m IPA (Isopropyl Alcohol)
16 ft. (5 m) Methane*
16 ft. (5 m) LPG*
13 ft. (4 m) Polypropylene Pellets
16 ft. (5 m) Office Paper

*20” (0.5 m) high, 8” (0.2 m) with plume fire

**3600-L/LB only

Response Time

Typically 5 seconds. High speed 150 msec response to saturated signal

Adjustable Time Delay

Up to 30 seconds

Sensitive Range

1 sq. ft. (0.1 sq. m) n-heptane pan fire from 50 ft. (15 m)

Field of View

100o Horizontal, 95o Vertical

Built-in-Test (BIT)

Manual and Automatic

Temperature Range

Operating: -67oF to 167oF (-55oC to 75oC)

Operating Option: -67oF to 185oF (-55oC to 85oC)

Storage: -67oF to 187oF (-55oC to 85oC)


Up to 95% non-condensing (withstands up to 100% RH for short periods)

Heated Options

To eliminate condensation and icing on the window

Electrical Specifications

Operating Voltage: 24 VDC nominal (18-32 VDC)

Power Consumption:

Standby: Max. 90 mA (110 mA with heated window)

Alarm: Max. 130 mA (160 mA with heated window)

Cable Entries: 2 x ¾” - 14 NPT conduits or 2 x M25 x 1.5 mm ISO

Wiring: 12 - 22 AWG (2.5 mm2 - 0.3mm 2)

Electrical Input Protection: According to MIL-STD-1275B

Electromagnetic Compatibility: EMI/RFI protected to EN61326-3 and EN61000-6-3

Electrical Interface: The detector includes twelve (12) terminals with five (5) wiring options (factory set)



  • Alarm, Fault, and Auxiliary
  • SPST volt-free contacts rated 5A at 30 VDC or 250 VAC

4-20 mA (stepped)


  • Sink (source option) configuration
  • Fault: 0 + 1 mA
  • Warning: 16 mA +/- 5%
  • BIT Fault: 2 mA +/- 10%
  • Alarm: 20 mA +/- 5%
  • Normal: 4 mA +/- 10%
  • Resistance Loop: 100-600 ohms

HART Protocol: Optional HART communication on the 0-20 mA analog current (FSK) – used for maintenance, configuration changes and asset management, available in mA source output wiring options RS-485: RS-485 MODBUS compatible communication link that can be used in computer control installations

Mechanical Specifications

Materials/Enclosure Options: Heavy-duty copper free aluminum (less than 1%), red epoxy enamel finish (ATEX Approval only)

Stainless Steel 316L with electro polish finish (FM or ATEX Approval)

Mounting: Stainless Steel 316L with electro polish finish


Detector: 4” x 4.6” x 6.18” (101.6 x 117 x 157 mm)


Aluminum: 2.8 lb. (1.3 Kg)

Stainless Steel 316L: 6.1 lb. (2.8 Kg)

Tilt Mount: 2.2 lb. (1.0 Kg)

Environmental Standards: Meets MIL-STD-810C for Humidity, Salt & Fog, Vibration, Mechanical Shock , High Temp, Low Temp Water and Dust: IP66 and IP67 per En60529, NEMA 250 6P


Hazardous Area

  • ATEX & IECEx

    Ex II 2 GD
    Ex de IIB + H2 T5 (-55o to 75oC)
    Ex de IIB + H2 T4 (-55o to 85oC)
    Ex tD A21 IP66/X7 T 95oC
    Ex tD A21 IP66/X7 T 105oC

  • FM/CSA

    Class I Div. 1, Groups, B, C & D
    Class II/III Div. 1, Groups E, F & G

  • EN54-10 (LPCB)
  • FM-3260 (FM)
  • DNV Marine Approval


  • IEC61508 – SIL-2 (TUV)
  • PDO Approval: Petroleum Development Oman Certificate of Registration
  • ISO 9001:2008: Registered Quality System

Fire Simulator: 20/20-310

Tilt Mount: 3600-01

Weather Protector: 777163

Air Shield: 777650

Mini Laptop Kit: 777820

USB RS-485 Harness Kit: 79407

Laser Pointer (Detector Area Coverage): 777166

 Sentry IT Fire and Gas Detection Solutions

A brief introduction to the sales, design and manufacturing facilities for Sierra Monitor Corporation's Sentry IT fire and gas solutions.