3 m retroreflective with MSR for shiny targets
The Omron E3RA-RN21 is a retroreflective photoelectric sensor in the E3RA series, delivering a 3 m sensing distance with a minimum opaque object size of 75 mm diameter. The built-in Mirror Surface Rejection (MSR) means it ignores reflections off shiny packaging or polished machine surfaces — a common false-trigger source that standard retroreflective sensors pick up. Response time is 0.5 ms, fast enough to catch parts on a high-speed conveyor without the PLC missing an edge.
IP69K washdown — survives daily CIP
Rated IP67 and IP69K, the E3RA-RN21 withstands high-pressure hot-water washdown. The plastic body and right-angle M12 connector face keep sealing surfaces out of the direct spray path. Supply voltage is 10-30V DC, NPN output with selectable Light On or Dark On switching. Maximum load current is 100 mA, enough to drive a PLC input or small relay directly. The indicator light confirms target presence during setup without a separate test box.