IR-S Infrared Flame Detector

Control Systems


IR-S type infrared flame detector is an excellent high-sensitivity type superior in "reliability of detection", "maintainability" and "economy".

It can support diversification of boiler fuel and low NOx (nitrogen oxide) operation. By detecting "average value" and "variation" of infrared intensity of burner flame light which is transmitted through a light guide (optical fiber) to an infrared sensor (semiconductor element), the detector can distinguish the flame and the infrared rays due to the red heat of the furnace wall and detect the flame fluctuation in the burner ignition zone.

The IR-S type infrared flame detector has low-brightness flame detection sensitivity and a wide dynamic range, so that it can be applied to various fuels such as gas, heavy oil, and coal.



High Sensitivity Design

High sensitivity to the intensity of flame enables stable detection of the burner flame. The flame is detected through the unlit zone.

Extended Detection Range

The sensor has 100 times dynamic range of a conventional product and allows stable detection from slow combustion to a high intensity flame. No sensitivity adjustment is required for the sensor at the site.

Easy Maintenance

A spherical lens is used to eliminate the need to clean the sensor window during boiler normal operation.

Long-life Sensor

Because a long-life infrared semiconductor sensor element is used, periodic replacement is not necessary.

Fewer Number of Panels

The detector unit is compact with a space-saving design which allows one panel to cover 40 corners.

System Configuration

Flame Detector Panel


Flame Detector Panel


Flame Detector Unit

Flame Detector Main Unit


Flame Detector Main Unit


Cross Sectional View of Sensor Head

For Fuel Oil Burner

The following example applies to a fuel oil burner.



Sensor Unit

The specifications of the sensor unit are as follows.

Environmental protection Explosion-proof (Exd II BT4), waterproof
Dimensions Entire Length As required
Guide Pipe 50A (40A)
Detection Wavelength 500 - 1,100nm
Allowable Temperature Detector Head Component Not exceeding 200℃
Cooling Air Temperature Not exceeding 60℃
Air Pressure In-furnace pressure +1.5kPa or greater
Air Flow At least 1.0Nm3/min per sensor
(fan capacity should be designed at 1.5Nm3/min per sensor to account for when withdrawn inspection takes place)

Flame Detector Panel

The specifications of the flame detector panel are as follows.

Type Closed indoor self-standing type, with access hatches on front and back
Dimensions 2,300mm (H) ×810mm (W) ×800mm (D)
  • Flame Detector Unit
  • Redundant Power Supply Units
  • Terminal Unit
Output Signals Flame on 1a
Low luminance level 1a
Power loss 1b
Contact capacity AC/DC 48V, 1.25A
Ambient Temperature 0 to 50℃


Retrofit or upgrade with a new type of flame detector system will not requires boiler side modifications. Many of existing facilities and parts will be reused.

Equipment Name Existing Methods of Flame Detection
UV Type IR Type
Sensor Unit Replaced Replaced
Flame Detector Panel Replaced Replaced
Sensor Cable Reused Replaced
Guide Pipe Reused Reused
Cooling-air Piping Reused Reused
Cooling Fan Reused Reused