Panasonic compact light curtain SF4-AH80 is built into a highly flameproof enclosure conforming to the IEC 61946 (Type4). The light curtain can be safely used in any workplace throughout the world where flameproof performance is required. A single light curtain is sufficient for production lines with high working heights such as vehicle body spray-painting lines. The beam-axis alignment is easy since angle adjustment is possible with the enclosed rear mounting bracket. The beam-axis alignment indicators are distributed along the light curtains in four sections. As the indicators of the sections whose beam channels are aligned light up in red, the user can easily verify which beam channel axes have become aligned. Once all beam channels have become aligned, the indicators light up in green. A double-scanning method and retry processing are some of Panasonic Industrial Devices SUNX's unique new technologies that help to avoid momentary interference from extraneous light coming from nearby equipment. A reduction in operating errors resulting from extraneous light interference can mean less frequent machinery stoppage and reduced amount of time when a production line is not running. No interference prevention lines are required between different items of equipment, so that sensors can be installed with greater flexibility.