Siemens QRI Series Infrared Flame Detectors

Siemens QRI Series infrared flame detectors monitor gas, oil and other infrared-emitting flames in industrial combustion systems. Equipped with an infrared-sensitive photoresistor, an integrated flame signal amplifier and DC 0–5 V signal output, they work with compatible Siemens LMV5 burner controls. Frontal and lateral sensing versions are available for continuous or intermittent flame supervision in industrial boilers and heating equipment.

Product Description

Siemens QRI Series Infrared Flame Detectors for Industrial Burners

Siemens QRI Series infrared flame detectors are designed to supervise gas, oil and other flames that produce infrared radiation. Working with compatible Siemens LMV5 burner control systems, they provide flame monitoring for industrial combustion equipment.

Key Features

  • Infrared-sensitive photoresistor with an approximate spectral response of 1–3 µm
  • Built-in flame signal amplifier
  • Frontal and lateral flame sensing configurations
  • Designed for compatible Siemens LMV5 burner controllers
  • Supports continuous and intermittent burner operation
  • Analog flame signal output of DC 0–5 V
  • Impact-resistant black plastic housing with a dust-tight lens
  • IP54 enclosure protection

Infrared Flame Detection Principle

The QRI detector incorporates an infrared-sensitive photoresistor that responds to variations in infrared radiation emitted by combustion flames.

An integrated electronic circuit converts these changes into an electrical flame signal for the connected burner controller. Electronic filtering helps suppress steady background radiation and interference caused by mains-frequency harmonics.

Available Siemens QRI Models

  • QRI2A2.B180B: Infrared flame detector with frontal illumination
  • QRI2B2.B180B: Infrared flame detector with lateral illumination
  • QRI2B2.B180B1: Lateral illumination detector supplied with a straight flange and mounting clamp

Industrial Applications

Siemens QRI infrared flame detectors are suitable for gas and oil burner flame supervision in industrial boilers, industrial heating systems and other combustion installations using compatible Siemens LMV5 controls.

The detector must be installed and operated according to Siemens technical and safety instructions, including verification of the selected burner control version.

Installation and Safety Considerations

Position the detector behind the burner's baffle plate to reduce interference from hot surfaces and unrelated infrared radiation sources. Installation, wiring, commissioning and safety testing must be performed by qualified personnel.

Specifications

Siemens QRI Series Infrared Flame Detector Technical Specifications

ManufacturerSiemens
Product FamilyQRI Series
Detector ClassificationInfrared Flame Detector
Sensing TechnologyInfrared-sensitive Photoresistor
Spectral Sensitivity BandApprox. 1–3 µm
Operating Supply VoltageDC 14 V ±5%
Test VoltageDC 21 V ±5%
Analog Flame Signal VoltageDC 0–5 V
Power Consumption< 0.5 W
Ingress ProtectionIP54
Electrical Safety ClassClass II
Integrated Connection Cable Length1.8 m
Maximum Cable Extension100 m
Ambient Operating Temperature-20 to +60°C
Short-duration Temperature LimitUp to +75°C (maximum 1 minute)
Relative Humidity< 95% RH
Maximum Installation Altitude2,000 m above sea level
Vibration ResistanceMax. 1 g / 10–500 Hz
Approximate Weight with 1.8 m Cable0.175 kg
Mounting OrientationOptional
Compatible Burner ControllersSiemens LMV5 Series

Siemens QRI Detector Model Comparison

Detector Model Flame Viewing Direction Cable Length Included Accessories
QRI2A2.B180B Frontal 180 cm None included
QRI2B2.B180B Lateral 180 cm None included
QRI2B2.B180B1 Lateral 180 cm Straight flange and clamp

Technical Note: Confirm the complete detector model, LMV5 compatibility, flame viewing direction, cable requirements and applicable Siemens installation instructions before ordering or commissioning.