RG2 optical linear encoder

Non-contact encoders featuring high-resolution readheads and Renishaw’s ubiquitous gold tape scale, available on reels for easy stock control.

Zero friction and zero mechanical hysteresis.

High performance and high reliability.

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RGH22 + RGH24The RG2 is an open, non-contact optical linear encoder system, eliminating friction and wear whilst permitting reliable high speed, high resolution operation. The unique 20 µm pitch optics ensure excellent signal stability in conditions considered unsuitable for most open optical linear encoders.

 

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RGH22 linear encoder RGH24 linear encoder RGH25 linear encoder RGH26 linear encoder

RGH22 optical linear encoder

 

 

RGH24 optical linear encoder

 

 

RGH25 optical linear encoder

 

 

RGH26 optical linear encoder

 

Options

Available with 20 µm analogue signal period or digital resolutions from 5 µm to 5 nm. All RG2 linear encoder systems incorporate a unique, integral set-up LED, which lights green when optimum installation has been achieved. Reference mark and/or limit switch outputs are available on all models of readhead. The reference mark provides a repeatable home or zero position, whilst the limit is used as an end of travel indicator. The RGH22 has a dual-limit option, which gives a unique output for each end of travel.

Technical

End lit optics + textAn infra-red LED emits light onto the angled scale facets where it is directed back into the readhead through a transparent phase grating. This produces sinusoidal interference fringes at the detection plane within the readhead. The optical scheme averages the contributions from many facets and effectively filters out signals not matching the scale period. This ensures signal stability even when the scale is contaminated or slightly damaged.

Thermal characteristics often play a significant role in determining overall measurement accuracy. The RGS20-S tape scale is rigidly restrained at its ends and is therefore forced to match the thermal behaviour of the substrate, removing the need to compensate for yet another coefficient of expansion.

Low short-term errors are assured by the unique optical design, typically giving less than ±0.15 µm cyclic error (or sub-divisional error). This is included within the linearity specification of ±0.75 µm in 60 mm or ±3 µm in any metre length.

RG2 readheads offer a durable scale with excellent metrology that can be cut to any length. RGS20-S gold plated tape scale is lacquer coated and requires none of the careful handling and cleaning most traditional scales need. A self-adhesive backing enables quick and easy installation with a range of applicators to suit the readhead type. To complete the installation, reference mark, limit switch actuators, and end clamps are simply glued into place.

 

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News

  • News article: Breakthrough mobile technology relies on Renishaw encoders [157kB] News article: Breakthrough mobile technology relies on Renishaw encoders

    A revolutionary mobile phone antenna has been developed by UK company Sarantel, based on the company's patented PowerHelix™ technology. When other conductors or the user’s hand or head are next to the antenna, performance is completely unaffected, unlike conventional antennas. The unique manufacturing process uses a special purpose machine from Finnish company Citam Assembly Automatics Oy, fitted with Renishaw linear encoders to give very high accuracy.

  • News article: MYDATA take a different approach to the design of large-board SMT machines [177kB] News article: MYDATA take a different approach to the design of large-board SMT machines

    MYDATA is one of the world’s leading developers and suppliers of pick and place machines for the electronic industry, set apart from other manufacturers by the flexibility and fast change-over their machines offer. Its new generation of large-board machines has broken new ground, with recently integrated Renishaw linear encoders being key to the performance.

  • News article: Renishaw scales facilitate micro-machining research [123kB] News article: Renishaw scales facilitate micro-machining research

    Special equipment has recently been installed at the University of Southampton by Ionoptika Ltd., for research into one of the most demanding of applications; micro-machining. Among the highly specialised suppliers involved is Renishaw, whose RG2 scale and RGH25 UHV readheads provide the crucial means of positioning for the nanometric movements required. People outside this discipline often find it hard to comprehend just how minute such work is – for example, Ionoptika’s full company logo can be etched 20 μm wide on a typical metallic screen mask.

3D models (step format)

Next steps

Contact us online if you require more information or you have a pricing query, or alternatively you may like to speak directly to your local Renishaw office.