Omron E3FB-TP21 is a through-beam photoelectric sensor set (transmitter and receiver) from the E3FB series, housed in a cylindrical M18 threaded brass body with a right-angle face. It's designed for opposed-mode sensing over a 20m range, detecting opaque objects as small as 7mm diameter. Output is PNP, selectable Light On or Dark On, with a 100mA load capacity. The M12 4-pin connector simplifies field replacement — pull the old sensor, plug in the new one. Runs on 10-30V DC and includes output short-circuit, output reverse polarity, and supply reverse polarity protection — so a miswire during commissioning won't kill the unit.
Sensing distance is 20 m. Response time is 0.5 msec. IP67 and IP69K ratings mean this sensor handles washdown environments — food processing, car washes, or outdoor installations with high-pressure spray. Brass body resists corrosion in wet or acidic atmospheres. The red LED emitter is visible through dirt or condensation, and the built-in indicator lights on the sensor body give instant alignment feedback — useful when adjusting a right-angle head in a tight bracket.