Omron E3T-ST31 5M Ultracompact Through-Beam Photoelectric Sensor
Omron E3T-ST31 5M is an ultracompact through-beam photoelectric sensor designed for sensing targets across a 2 m working distance. A red LED establishes the optical path between the emitter and receiver, while the built-in amplifier processes the change produced when a target interrupts the beam. Its NPN output supports compatible machine-control inputs, and Light-ON operation defines the specified switching logic. The sensor operates from 12 to 24 VDC and includes a 5 m pre-wired cable. Maximum current consumption is 30 mA, consisting of 10 mA for the emitter and 20 mA for the receiver. Within the E3T Series, the E3T-ST31 5M provides the extended-cable Light-ON version. Similar 2 m through-beam sensors can be reviewed across Omron Sensor Products.
| Brand | Omron |
| Product | Photoelectric Sensors |
| Model Number | E3T-ST31 5M |
Omron E3T-ST31 5M Photoelectric Sensor - Technical Specifications
| Specification | Value |
|---|---|
| Sensing Method | Through-beam |
| Shape | Square type |
| Sensing Distance | 2m |
| Power Supply Voltage | 12 to 24 VDC |
| Output Configuration | NPN |
| Connection Method | Pre-wired cable length 5m |
| Current Consumption | 30 mA max. (Emitter 10 mA max., Receiver 20 mA max.) |
| Light Source (Wavelength) | Red LED |
| Operation Mode | Light-ON |
| Response Time | 1 ms max. |
| Degree Of Protection | IP67 |
| Material | Polybutylene terephthalate |
| Material Lens | Denatured Polyarylate |
| Weight | 40g |
The Omron E3T-ST31 5M Photoelectric Sensor uses through-beam sensing across a 2 m distance with a red LED optical source and NPN output. The optical beam extends between the emitter and receiver, and interruption by a target produces the switching condition processed by the built-in amplifier. Light-ON operation provides the specified output logic, while response time is 1 ms maximum. The sensor operates from 12 to 24 VDC and includes a 5 m pre-wired cable. Maximum current consumption is 30 mA, divided between 10 mA maximum for the emitter and 20 mA maximum for the receiver. Its square ultracompact construction supports sensing positions where mounting space is limited and longer cable routing is required.
For an Omron ultracompact through-beam sensor requiring NPN output and an extended pre-wired connection, the applicable model is the E3T-ST31. The supplied specification lists IP67 protection along with PBT and denatured polyarylate materials. Its 2 m sensing range, Light-ON behavior, and 12 to 24 VDC supply support compact machine installations using separate emitter and receiver elements. Search terms such as Omron 2 m NPN sensor and Omron 5 m cable photoelectric sensor also match this configuration. For a related Dark-ON model with the same 2 m sensing distance, NPN output, and 5 m cable, see the E3T-ST32 5M. The primary functional difference is the specified switching logic.
