Optical sensor for acquisition of rotational speeds

The laser sensor developed by ROTEC is used to detect rotational speeds according to the reflex method. Depending on the application, a ROTEC zebra disk or zebra band is scanned.

Technical drawing


  • Fiber optic cable available with textile or metal cladding
  • The target can be scanned from the front or via a deflection mirror at a 90° angle
  • Available with ROTEC zebra disc/zebra tape

Optical fiber with metal cladding
Item number: SELAS4

Optical fiber with textile cladding
Item number: SELAS5

Technical data

Sensor head

  • single piece

Sensor surface

  • laser beam face side or angled at 90°
  • via deflection mirror

Sensor length

  • 45 mm

Sensor type

  • laser probe with optical fiber, requires downstream ROTEC Laser Tachometer

Sensor housing

  • stainless steel
  • external thread M10x1
  • standard thread length 15 mm


  • integrated optical fiber, textile or metal jacketed (5 m)

Maximum gearwheel frequency

  • 65 kHz with downstream ROTEC Laser Tachometer

Requirements encoder wheel/shaft                                   

  • applied with ROTEC Zebra discs and tapes

Sensing gap

  • with typ. Line widths ≥ 1 mm: 30 to 80 mm
  • with min. line width of 0.25 mm: 20 mm

Temperature range

  • -10 °C to +50 °C