ISO 9001:2008
Modern means of measuring equipment

Series RF251

Рифтэк (Belarus)

Linear absolute encoders series RF251
Linear absolute encoders series RF251

Absolute linear encoders are designed for measuring and controlling the movement, size, beat, location and surface profile, deformation of technological objects.
RF251 series encoders are designed for operation under severe conditions (wide temperature range, IP57 protection level).
Are used for high-precision contact measurement:
  • size of the object;
  • thickness of the object;
  • object movement;
  • beats;
  • deviations from flatness;
  • surface deformations.
How it works
Principle of photoelectric scanning of a special scale, connected with the measuring tip of the sensor, is based on the operation of the sensors. The radiation from the LED 1 is collimated by the lens 2 and is directed to the scale 3. The image of the section of the scale 3 is read by the CMOS ruler 4 and analyzed by a signal processor that calculates its position.
Compared to incremental encoders, absolute sensors have several advantages: the absolute position of the measuring tip is determined immediately after the power is turned on and eliminates the need to search for a reference mark; the probability of accumulation or loss of counting pulses during shocks, vibrations and reverse is excluded.


Model RF251-3 RF251-25 RF256-15 RF256-35 RF256-55
Range of control, mm: 3 25 15 35 55
Deviation (Т=20 °С), mkm: ± 2 ± 3
Increment, mkm: 0.1 or 0,5 or 1 or 5 or 10
Output interface:
  • digital
  • RS422 (RS485 and SSI or RS232) and (EncD5 or EncD10 - emulation of quadrature signals of incremental converters)
  • analog
  • нет 0 … 20 mA (load 500 Om) or 0 … 10 V
    External sync input: no opto-isolated
    Logical outputs: no two outputs, NPN: 100 мА max; 40 В max
    Process indicator: no two-color LED
    Supply voltage, V: 12 (without analog output) 15 (with analog output)
    Max. power consumption, W: 0,75
    Protection class: IP57 IP50
    Process temperature, °С: -40 … +50 -10 … +50
    Mass (without cable), g: 110 110 150 180

    Additional information

    See also: