RGH25F linear encoder system

The open, non-contact and ultra-compact RGH25F readhead uses Renishaw's unique flexible 20 µm RGS20-S tape scale and offers resolutions to 5 nm. The low profile RGH25F features external interpolation through the REF interface, which offers automatic gain control, offset control, and diagnostic capabilities.

The RoHS compliant REF interface replaces the RGB series, bringing high-end SiGNUM™ performance and resolutions to 5 nm. Please note that the RGH25 readhead and RGB interface are now obsolete and have been replaced by the RGH25F and REF.

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RGH25F system features and benefits

• The ultra-compact, low mass readhead is ideal for space critical applications
• Non-contact design offers high speed, reliable operation with zero friction and zero wear
• Integral set-up LED on the interface enables easy readhead installation
• Filtering optics guarantee excellent signal stability in conditions unsuitable for most open, optical encoders
• Self-tuning adaptive electronics ensure high accuracy and long-term reliability
• Automatic gain control (AGC), automatic offset control (AOC) and automatic balance control (ABC) minimize cyclic error (<±50 nm)
• The reference mark provides a repeatable home position whilst the limit offers end of axis travel indication
• UHV compatible versions also available

Compare the RGH25F with alternative optical linear readheads.

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RGS20-S 20 µm pitch tape scale

20 µm RGS20-S is manufactured from a thin flexible steel strip, which is gold plated to give high reflectivity and corrosion resistance. It may be mounted, using adhesive backing tape, to most engineering materials, including metals, ceramics, and composites.

• Scale is supplied on a reel and can be cut to suit any axis length up to 70 m
• RGS-S scale matches the thermal behaviour of the substrate it is affixed to, simplifying thermal compensation
• Patented applicator tool enables fast and accurate scale installation
• Lacquer coated scale is easy to clean and resistant to handling
• 'Cut-to-measure' convenience ensures minimum waste and efficient inventory management
• ±3 µm/m linearity enables high accuracy with simple compensation

Technical specifications

Additional resources

Accessories and external interpolation options

For further information and product options, visit the encoder product configurator.