The Omron E3T-SR21 2M is a retroreflective photoelectric sensor from the E3T series, built for washdown environments with an IP67 rating and hygienic feature. It uses a red light beam and a reflector to detect opaque objects down to 27 mm diameter at distances from 30 mm to 200 mm. Output is NPN, light-on switching — the transistor sinks current (max 50 mA) when it sees the reflected light. Power it with 12-24 V DC. The 1 msec response keeps it fast enough for most packaging lines. Cable is 2 m, prewired with bare ends. The rectangular body is only 7 mm wide and 24 mm tall, with the optical axis exiting at a right angle — good for tight spaces where the reflector must mount off to the side.
Integration notes
Mounting: The 7 mm wide body clips onto a bracket or sits in a slot. The right-angle exit means the cable runs along the mounting surface, not straight out — plan cable routing accordingly. IP67 handles hose-down cleaning, but the connector end is bare wire, so use a sealed junction box or overmold it outdoors. The hygienic feature suggests the PBT housing and sealing are food-grade compatible, but the 2 m prewired cable limits flexibility if you need longer runs — use the bare ends to splice in a longer cable if required.