ISO 9001:2015
Modern means of measuring equipment
  • Eng

Optical incremental linear encoder RGH25F UHV

Renishaw plc (Graet Britain)

Encoder RGH25F UHV
Encoder RGH25F UHV

The reading head of the linear encoder RGH25F UHV is used with Renishaw´s RGS20-S scale tape, providing reliable feedback on the position in ultra-high vacuum conditions. It has proven itself over many years of operation, the RGH25F UHV head is used worldwide in semiconductor devices and scientific equipment, where exceptional reliability and the highest performance are required.

Compatibility with REF interfaces

In order to increase the efficiency and reliability of the service, the interfaces of the RGB and RGF series have been replaced by a REF interface that meets the requirements of the RoHS Directive and provides dynamic signal processing and resolution up to 5 nm! The reading head RGH25F UHV is manufactured in extremely clean conditions, using materials and glues with low gas evolution. The finished product is packed and sealed in a special bag in order to ensure proper cleanliness.

Scale tape that can be used in a vacuum

The RGS20-S scale tape features a high repeatability of measurement results and can be installed on substrates of most materials used commonly in the semiconductor industry and sectors where equipment for research activities is made. Such materials include, in particular, Invar, Zerodur, stainless steel and aluminum. After the ends of the scale are fixed to the substrate using the epoxy adhesive of the recommended type, the change in the state of the scale will correspond to the coefficient of thermal expansion of the substrate, and as a result, this system works as if the calibration was applied to the substrate itself.

Results of analysis of the composition of residual gases

The results of an independent analysis of the residual gases showed the suitability of the entire system as a whole for operation in a vacuum. The system can also be degassed at 120 degrees Celsius and then used in ultra-high vacuum conditions. Typical examples of the application of this system: feeding and moving semiconductor wafers and their verification, as well as conducting research.


Built-in LED
head position indicator
Measuring range, m: 50
Length, m: optical scale RGS20S from 0,1 to 50 (more than 50 m by special order)
optical scale RGS20PC from 1 to 50
Resolution of digital output signal RS422, nm: 5, 10, 20, 50 , 100, 200, 500, 1000, 5000
Resolution of analog output signal: 1 Vpp
Step of the scale, mkm: optical scale RGS20S 20
optical scale RGS20PC 20
Max speed, m/s: for digital output signal up to 5
for analog output signal up to 6
Clearance between reading head
and optical scale, mm:
0,8 0,1
System accuracy at 20 C, μm/m: 15 ( 3 with 2-point compensation)
Scale option: with self-adhesive base
Coefficient of thermal expansion, μm/m/: corresponds to the substrate material, the ends of the scale are fastened by clamps
Supply voltage, V: 5 5 % + 10 %
Current consumption (without load), mA: reading head 50
system 200
Material: optical scale RGS20S thin, flexible steel gilded strip with protective lacquer coating
optical scale RGS20PC thin, flexible steel gilded strip with protective polyester coating for increased resistance to the effects of aggressive chemicals
Cable: Flexible, braided, tinned copper, with single shielding, protected by PTFE insulation
Length of the cable, m: 1.5, 3, 5 (connector type D-sub (15-pin), not applicable in ultra-high vacuum, designed to connect to the REF-interface)
Dimensions of the reading head RGH24 (height × length × width), mm:: 10,5 × 36,0 × 13,5
Mass, g: reading head 9
interface 100
Mass of the cable, g/m: 23
Reference mark (zero): Magnetic actuator (one-way repeatability up to 1 resolution unit)
Limit switches: One switch
Temperature, : process from 0 to + 55
storage from 20 to + 70
degassing - 120 (only for reading head)
Degree of protection: reading head IP40
interface IP20
Maximum humidity
(without compensation), %:
process 80
storage 95
Process acceleration, m/s 2: 500
Impact (in non-operating state,
6 ms, half-sinusoidal impulse), m/s, 2:
Vibration (in operation mode, at, at 55-2000 Hz), m/s 2: not more than 100

Additional information