QRA50M Siemens Sensor

Overview

The Siemens QRA50M is a high-durability, self-checking ultraviolet (UV) flame detector designed for the supervision of gas or oil flames. Engineered for continuous or high-demand operation, this sensor is a critical safety component used in conjunction with the LFE50 flame safeguard system. It features a robust design with a rotating shutter mechanism to ensure reliable flame detection and prevent hazards like simulated flame signals in industrial burner systems.

Features

• Self-checking mechanism with an integrated synchronous motor and rotating shutter for continuous testing of UV cell responsiveness
• High-sensitivity UV photo-cell designed to detect gas flames and yellow or blue burning oil flames
• Die-cast alloy detector head with a quartz-glass lens for high-pressure environments
• Integrated 3/8 inch tapping for cooling air connection to prevent soot buildup and manage heat
• Durable IP54-rated housing providing protection against dust and water splashes
• Frontal light entry design specifically for mounting on viewing tubes directed toward the combustion chamber

Specifications

• Model: QRA50M
• Detection Type: Ultraviolet (UV)
• Spectral Range: 190 to 240 nm
• Operating Mode: Continuous operation (Self-checking)
• Protection Rating: IP54
• Max Pressure: 500 mbar on quartz-glass lens
• Weight: Approximately 0.75 kg (1.65 lbs)
• Compatible Control: Siemens LFE50 flame safeguard
• Replacement Bulb: Siemens part number 4 502 4268 0

Applications

• Supervision of gas flames and yellow/blue burning oil flames in industrial burners
• Monitoring of burners operating without interruption for more than 24 hours
• Ignition spark proving in high-demand combustion systems
• Use in environments requiring robust, self-monitoring flame detection such as large boiler plants and thermal processing units