Page 10 - Industrial Technology EXTRA 1st March 2021

The TONiC series is Renishaw’s high- tape scales. This type of scale is ‘mastered’ to the
performance incremental optical encoder system substrate and has a thickness of just 0.1 mm,
and features several scale options with different which enables the scale to expand and contract at
thermal characteristics. Used together with the Ti the same rate as the underlying machine axis.
interface, these encoders can achieve resolutions as Most of U-Precision's motion stages use large
fine as 1 nm in both linear and rotary applications, granite substrates that have a high thermal mass
while operating speeds remain as high as 3.6 m/s and a low coefficient of thermal expansion (CTE). In
at 0.1 µm resolution. TONiC encoder systems are this case, local air temperature changes that occur
quick and simple to install with wide set-up over short time intervals will not significantly affect
tolerances and calibration at the push of a button. the substrate dimensions, which offers better
Dynamic signal conditioning features increase the metrology.
stability of the output signal, while sub-divisional TONiC encoders are also available with ‘floating’
error (SDE) is lower than 30 nm. scales that freely expand independently of the
Increasing air temperature (due to motor heating mounting substrate, such as the RTLC and RELM
and other processes) can result in thermal series scales. The degree of thermal expansion in
expansion that changes the length of many these scales is determined by the CTE and
components, including encoder scales, inside temperature of the scale itself, so there is no need
manufacturing equipment. U-Precision uses mostly to factor in the expansion coefficient of the substrate
TONiC series encoder systems with RGSZ20S steel when performing thermal compensation.

March 2021 • INDUSTRIAL TECHNOLOGY EXTRA • p10