Safety light curtain for hand detection in guarded zones
The Omron F3SJ-A1740P25-TS is a Type 4 safety light curtain from the F3SJ-A series, designed for hand protection with a 25mm detection capability. Its 1740mm protective height and 20mm beam pitch (87 beams total) create a detection plane that catches fingers and hands reaching into a hazard zone — meeting the finger-protection class per IEC 61496-1. The operating range spans 0.2m to 7.0m, which covers most machine guarding distances from press openings to conveyor in-feed points.
What the ratings mean for fit
The 25mm detection capability is the key selection parameter: it resolves objects that size or larger, meaning it protects hands but not individual fingers (that would require a 14mm beam pitch). The 1740mm protective height covers a tall opening — think a press bed or a robot cell access — without stacking multiple curtains. The 20mm beam pitch gives 87 beams across that height, so there are no blind gaps large enough for a hand to slip through undetected. IP65 ingress protection means the emitter and receiver housings are dust-tight and protected against low-pressure water jets from any direction. This is sufficient for most dry machining environments and light washdown areas, but not for high-pressure or immersion cleaning (that would need IP67 or IP69K). The 24VDC supply is standard for safety circuits; the -10°C to 55°C operating temperature covers indoor factory conditions but not freezer or outdoor direct-sun applications.
Built-in blanking and muting
This model includes blanking and muting functions as standard features. Blanking lets you disable specific beams to allow fixed obstructions (like a machine frame or workpiece fixture) to pass through the detection zone without triggering a stop. Muting temporarily suspends the light curtain during a non-hazardous portion of the machine cycle — for example, when a part is being loaded through the curtain but the machine is in a safe state. Both features are configured through the controller, not hard-wired, which simplifies integration.