Omron E3T-ST12 2M Photoelectric Sensor
Omron E3T-ST12 2M is an ultrathin through-beam photoelectric sensor designed for sensing opaque targets across a 1 m distance. A 650 nm red LED establishes the optical path between the emitter and receiver, while the NPN open-collector output transfers the switching state to compatible control circuitry. Dark-ON operation is specified, and operate or reset time is 1 ms max. The sensor operates from 12 to 24 VDC, consumes up to 30 mA across both sensing sides, and includes a 2 m pre-wired cable. The stated target capability includes opaque objects from 2 mm diameter. Within the E3T Series, the E3T-ST12 2M provides the Dark-ON NPN option. Related small-target through-beam sensors are available across Omron Industrial Products.

| Brand | Omron |
| Product | Photoelectric Sensors |
| Model Number | E3T-ST12 2M |
Omron E3T-ST12 2M Photoelectric Sensor – Technical Specifications
| Specification | Value |
|---|---|
| Sensing Method | Through-beam |
| Sensing Distance | 1 m |
| Standard Sensing Object | Opaque, 2-mm dia. min. |
| Light Source | Red LED (650 nm) |
| Power Supply Voltage | 12 to 24 VDC , ripple (p-p) 10% max. |
| Output Configuration | NPN |
| Connection Method | Pre-wired 2 M cable |
| Current Consumption | 30 mA max. (Emitter 10 mA max., Receiver 20 mA max.) |
| Control Output | Load power supply voltage: 26.4 VDC max. Load current: 50 mA max. (residual voltage: 2 V max. for load current of 10 to 50 mA, 1 V max. for load current of less than 10 mA) Open-collector output |
| Operation Mode | Dark-ON |
| Response Time | Operate or reset: 1 ms max. |
| Indicators | Operation indicator (orange), Stability indicator (green) |
| Ambient Illumination | Incandescent lamp: 5,000 lx max., Sunlight: 10,000 lx max. |
| Ambient Temperature Range | Operating: −25 to 55°C Storage: −40 to 70°C (with no icing or condensation) |
| Ambient Humidity Range | Operating: 35% to 85% Storage: 35% to 95% (with no condensation) |
| Insulation Resistance | 20 MΩ min. at 500 VDC |
| Dielectric Strength | AC1,000V, 50/60 Hz for 1 min. |
| Vibration Resistance | 10 to 2,000 Hz, 1.5-mm double amplitude or 300 m/s2 for 0.5 hours each in X, Y, and Z directions |
| Shock Resistance | 1,000 m/s2 3 times each in X, Y, and Z directions |
| Protection Circuits | Power supply and control output reverse polarity protection, Output short-circuit protection |
| Degree Of Protection | IEC 60529 IP67 |
| Material | PBT (polybutylene terephthalate), Denatured polyarylate |
| Weight | Approx. 40 g |
The Omron E3T-ST12 2M Photoelectric Sensor uses through-beam sensing across a 1 m distance for opaque targets. A 650 nm red LED establishes the optical path between the emitter and receiver, while the NPN open-collector output transfers the switching state from the receiving side to compatible control circuitry. Dark-ON operation defines the specified logic. The sensor operates from 12 to 24 VDC, with total current consumption of 30 mA max., consisting of 10 mA max. for the emitter and 20 mA max. for the receiver. Operate or reset time is 1 ms max., and a 2 m pre-wired cable provides connection. The stated minimum opaque target diameter is 2 mm.
For an Omron Dark ON through beam photoelectric sensor requiring NPN output and 1 m sensing, the corresponding model is the E3T-ST12. Output load current is specified at 50 mA max., with load supply voltage up to 26.4 VDC. Operating temperature extends from -25 to 55°C, while storage extends from -40 to 70°C without icing or condensation. Reverse-polarity and output short-circuit protection are listed. Its specification also suits searches for an Omron 2 mm target sensor and Omron 650 nm through beam sensor. For the related Light-ON NPN version with the same 1 m range, see E3T-ST11 2M.


