What this sensor is and what it does
The Omron E3JK-DS30M2 is a diffuse-reflective photoelectric sensor that uses an Infrared LED (950nm) light source. It detects objects up to 300 mm away from a standard white paper target (100×100 mm). The relay output switches loads from 0 to 3 A, making it a direct replacement for older panel-wired sensors without needing a separate amplifier or solid-state interface. It runs on either 12 to 24 VDC or 24 to 240 VAC, so it drops into existing control circuits without a supply swap — handy for a line-down swap where the panel voltage isn't standardized. The operation mode is fixed to Dark-ON, meaning the output relay energizes when the received light drops below the threshold (object present). No Light-ON/Dark-ON selector here — if your application needs Light-ON, this isn't the part.
Sourcing and lifecycle reality
This part is in mature lifecycle stage. Confirm availability and pricing at quote time.
What the ratings mean for fit
The 300 mm sensing distance is measured against a white paper target. Real-world range drops with darker or less reflective surfaces — the differential distance is 20% max of the sensing distance, so expect some hysteresis. For a dark target (black rubber, matte plastic), the effective range may be half the rated value or less. The relay output handles 0 to 3 A resistive load. That's enough to drive a small contactor coil, a PLC input, or an indicator lamp directly. No transistor switching here — the relay gives you isolation but also a finite mechanical life; factor that into high-cycle applications. Emitter draws 15 mA DC max, receiver 20 mA DC max.