Pepperl+Fuchs LA31/LK31/25/31/115 Thru-beam Sensor

Thru-beam Sensor

Pepperl+Fuchs  Thru-beam Sensor Series 31 is a range of cost-effective and, most importantly, reliable photoelectric sensors for standard applications in the fields of material handling and logistics, and for monitoring industrial doors, elevators, and automatic gates. The ultrasonic-welded plastic housing provides a high degree of protection, making these sensors ideal for tasks in harsh outdoor conditions.

These sensors are currently the most compact “wide range power supply sensors” that can work with any DC and AC voltage between 24 V and 240 V. In addition to the robust technology, the sensors offer numerous product details that help the user with assembly, connection and operation


  • Photoelectric sensor for detecting people, objects and vehicles
  • Large construction with small housing
  • Not sensitive to ambient light
  • Version for universal voltages
  • Relay output
  • Version with accessories in scope of delivery

Technical Data

System components
Emitter LA31/115
Receiver LK31/25/31/115
General specifications
Effective detection range 0 … 30 m
Threshold detection range 43 m
Light source LED
Light type modulated visible red light , 630 nm
Alignment aid LED yellow:
1. LED illuminates: Sufficient light signal received, emitter and receiver alignment is correct
2. LED flashes: Reaching switching point
3. LED off: Light beam is interrupted or the alignment is out
Diameter of the light spot approx. 800 mm at a distance of 30 m
Angle of divergence Emitter: 0.5 ° , Receiver: 1.5 °
Ambient light limit 50000 Lux
Accessories provided 2 x Mounting bracket OMH-RL31-01 and mounting materials
Functional safety related parameters
MTTFd 790 a
Mission Time (TM) 20 a
Diagnostic Coverage (DC) 0%
Indicators/operating means
Operation indicator LED green: power on
Function indicator LED yellow:
1. LED lit constantly: signal > 2 x switching point (function reserve)
2. LED flashes: signal between 1 x switching point and 2 x switching point
3. LED off: signal < switching point
Electrical specifications
Operating voltage 24 … 240 V AC
12 … 240 V DC
No-load supply current Emitter: ≤ 40 mA
Receiver: ≤ 3 mA
Power consumption Emitter: ≤ 1 VA
Receiver: ≤ 1 VA
Switching type light on
Signal output Relay, 1 alternator
Switching voltage max. 250 V AC/DC
Switching current max. 3 A
Switching power DC: max. 150 W AC: max. 750 VA
Switching frequency ≤ 20 Hz
Response time ≤ 25 ms
Product standard EN 60947-5-2
Compliance with standards and directives
Standard conformity
Standards EN 62103
Approvals and certificates
EAC conformity TR CU 020/2011
TR CU 004/2011
Protection class II , rated voltage ≤ 250 V AC with pollution degree 1-2 according to IEC 60664-1 Output circuit basis insulation of input circuit according to EN 50178, rated insulation voltage 240 V AC
CCC approval Certified by China Compulsory Certification (CCC)
Ambient conditions
Ambient temperature -25 … 55 °C (-13 … 131 °F)
Storage temperature -40 … 70 °C (-40 … 158 °F)
Mechanical specifications
Degree of protection IP67
Connection Emitter: 2 m fixed cable , 2-wire
Receiver: 2 m fixed cable , 5-wire
Housing Polycarbonate
Optical face PMMA
Mass Emitter: 116 g
Receiver: 131 g


Contact us : or visit to our E-Commerce

Download Datasheet: Pepperl+Fuchs LA31/LK31/25/31/115

Another Article:

Similar Posts