Compact OEM distance sensor module

The RF51M is an OEM laser module to integrate laser distance measurement capabilities into existing measurement equipment.
It combines the laser distance measurement module of the LDM51A with an own interface board in a compact aluminum frame. The OEM laser module RF51A measures contactless the distance between itself and nearly every surface and material. Up to a distance of 100 m no additional reflectors are required for measuring. The maximum distance exceeds the range of 200 m. Due to the high measuring frequency of 100 Hz also fast movements of the target can be captured.


The OEM laser module RF51A operates with a modulated visible laser with low beam divergence. Newly developed algorithms and most modern technologies of the opto-electronic signal processing allow a save, highly precise and fast distance measurements that can be applied in almost all areas of machinery and plant engineering.
Other application examples are level measurement, detection of geometric dimensions like length, width or thickness and position measurement.
Due to the compact dimensions of the aluminum frame the RF51M can easily be integrated into existing sensor systems. With its 5 V power supply and the UART interface the RF51A is ready to be connected to microcontrollers or single-board computers.

  • Plant automation and process technology
  • Positioning applications in transportation and logistic
  • Distance measurement in mining, building, forestry and material-handling technology
  • Machine-observation and -positioning in metal industry e.g. rolling-mills, de-coiler
  • Long term observation of buildings and technical installations, e.g. churches, tide gates, docks
  • Position and height detection in crane applications
  • Level measurement in silos and heaps on materials like sand, earth, feed, cereals, cement
  • Thickness, length and width detection
  • Volume and area calculation
  • Diameter of steel coils
  • Distance measurement on hot glowing steel with temperatures over 1300 °C


  • OEM laser module
  • Contactless laser distance measurement on nearly every type of surface
  • Reliable operation in outdoor applications under high common light influence
  • Measuring even on extremely bad reflecting targets (coal, rubber, rust)
  • Riskless usage due to eye-safe visible laser beam (Laser class 2, EN 60825-1:2007)
  • 3 programmable digital output lines
  • Freely programmable and scalable analogue interface (4 mA ... 20 mA)

Technical Data

General measurement range 0.15 m ... 200 m
Typical measurement ranges
On special reflective target (Oralite 5200)
Reflecting foil (3M 3279)
Natural surfaces, 80% remission
Natural surfaces, 6% remission

50 m ... 200 m

0.15 m ... 100 m
0.15 m ... 100 m

0.15 m ... 85 m
Accuracy, absolute (1 σ) ≤ ± 3.9 mm
Repeatability, max. (standard deviation) ± 0.6 mm
Resolution 0.1 mm
Measurement period, min. 10 ms
Laser class Laser class 2, EN 60825-1:2014
Laser Wavelength 655 nm
Laser beam divergence < 0.2 mrad
Interfaces RS232, CMOS level 3.3 V
Digital switching output lines 3 x High-Side-Switch, CMOS level 3.3 V
Analog Interface 4 mA ... 20 mA
Trigger line 1 x Trigger IN / OUT, CMOS level 3.3 V
Connector 1x 16-pin male connector, FH12-10S-0.5SH(55)
Power supply 5 VDC ± 0.5 V
Power consumption < 2.5 W
Operating temperature -10 °C ... 50 °C
Dimensions 50 mm x 35 mm x 27 mm (l x w x h)
Weight 70 g
MTBF 35,435 hours (MIL HDBK 217 F)



Mr. Daniel Strandt

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