Photoelectric Sensor OMRON E3S-AT81/ E3S-AT11/ E3S-AT21/ E3S-AT31/ E3S-AT41/ E3S-AT16/ E3S-AT36/AT61/ E3S-AT71/ E3S-AT91 IP67

Mounting Type

IP67 groove sensor

Manufacturer Part Number

E3S Series

Brand Name

omron

Usage

SENSOR

active area

-

Description

Slot photoelectric sensor 0.1mm

Type

Photoelectric Sensor

Place of Origin

Japan

Series

-

Features

-

Theory

-

Output

NPN/PNP

Description

-

Viewing Angle

-

Response Time

-

Voltage - Supply

LED sensor

Wavelength

-

Dark Count Rate

In details:

Omron Corporation – E3S-AT Series Photoelectric Sensors (IP67)

4

The E3S-AT series is a heavy-duty rectangular photoelectric sensor line designed for industrial automation environments. All listed models feature:

• Protection rating: IP67 (dustproof and water-resistant)

• Rugged ABS/PBT housing

• Red LED light source

• Stable detection with built-in amplifier

• Light-ON / Dark-ON selectable (model dependent)

• Typical supply voltage: 12–24 VDC

• Industrial M12 or cable output versions

Below is a detailed explanation of each model.

1. E3S-AT11

Type: Through-beam (Receiver)
Function: Receives light from a paired emitter (typically E3S-AT61).
Sensing distance: Up to 15–20 m (when paired)
Output: NPN transistor
Application:

• Long distance detection

• Conveyor object counting

• Pallet detection

• Transparent or small object detection

Characteristics:

• Highest stability

• Excellent for dusty environments

• Requires separate emitter unit

2. E3S-AT61

Type: Through-beam (Emitter)
Function: Emits red LED beam toward AT11 receiver
Role: Must be paired with AT11
Application:

• Used in high-speed production lines

• Large object detection

• Long-range alignment systems

Characteristics:

• No output (light emitting only)

• Long detection range

• Best immunity to object color variation

3. E3S-AT21

Type: Retro-reflective
Sensing distance: Approx. 3–5 m (with reflector)
Output: NPN
Function: Detects object when beam between sensor and reflector is interrupted

Application:

• Carton detection

• Packaging lines

• Automated warehousing

Characteristics:

• Requires reflector

• Easier installation than through-beam

• Moderate range

4. E3S-AT31

Type: Diffuse reflective
Sensing distance: Approx. 100–300 mm
Output: NPN

Function: Detects object based on reflected light from object surface

Application:

• Small parts detection

• Component presence check

• Assembly station verification

Characteristics:

• No reflector needed

• Affected by object color

• Short-range precision sensing

5. E3S-AT41

Type: Diffuse reflective (Longer range version)
Sensing distance: Approx. 400–1000 mm
Output: NPN

Application:

• Box detection on conveyors

• Product presence detection

• General factory automation

Characteristics:

• Longer sensing distance than AT31

• More sensitive to reflectivity differences

6. E3S-AT16

Type: Through-beam (Receiver) – PNP version
Output: PNP
Function: Same optical principle as AT11 but with PNP output

Application:

• PLC systems using sourcing input logic

• European control panels

7. E3S-AT36

Type: Diffuse reflective – PNP version
Output: PNP
Sensing distance: ~300 mm

Application:

• Machine builders using PNP standard

• Packaging equipment

8. E3S-AT71

Type: Retro-reflective – PNP version
Output: PNP
Sensing distance: 3–5 m

Application:

• Carton detection

• Automated storage systems

9. E3S-AT91

Type: Background suppression diffuse
Sensing distance: ~100–500 mm

Function: Detects objects at a fixed distance while ignoring background

Application:

• Conveyor lines with background metal

• Precise positioning systems

• Robotics part confirmation

Advantages:

• Less affected by background reflection

• Stable detection in variable environments

Summary Comparison

Selection Guidance for Automation Systems

• Long distance, high reliability: AT11 + AT61

• General conveyor detection: AT21 or AT71

• Short range component sensing: AT31 / AT36

• Mid-range carton detection: AT41

• Precise background ignore: AT91