The yellow flame detector for Siemens burner control boxes is used to monitor oil flames in the visible field. The QRB4 is used in conjunction with burner control boxes for intermittent oil burners. The QRB4 device and this data sheet are intended for original equipment manufacturers (OEMs) that integrate QRB4 devices into their products.

QRB4s are used to monitor yellow oil flames in conjunction with the LME7 (upon request), LME8 (upon request), LMO, LMV2, and LMV3 burner control boxes. It is designed for both front and side (90°) illumination.

The QRB4's maximum spectral sensitivity is approximately 540 nm, thus perfectly covering the maximum visible light radiation range of yellow oil flames. Since the QRB4 can also detect fractions of the radiation spectrum from other light sources (boiler room lighting, sunlight, etc.), the usual provisions regarding protection against external light apply.