A company of Schneider Electric

The Spherosyn Advantage
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Linear encoders and scales manufactured by Newall are specifically engineered to meet the extreme demands of the machine shop environment, as proven by the more than 400,000 digital readout systems in place worldwide.

Environmental Protection
All variants of Newall linear encoders carry an Ingress Protection (IP) rating of 67 (IEC 529). The encoders are fully submersible and will continue to provide accurate and dependable readings under the harshest conditions. Unlike most glass-scale systems, no air purging is required. Dirt, swarf, cast iron dust, graphite dust and other common contaminates will not effect the performance of the linear encoder system.

Shock and Vibration
In comparison to other linear displacement technologies, Newall's linear encoders are tolerant to high degrees of vibration and shock.

• Shock and Impact (11ms IEC 69-2-6):
  Spherosyn™ technology = 1000m/s2 (100g)
• Vibration (55 - 2000Hz IEC 68-2-27):
  Spherosyn™ technology = 300m/s2 (30g)

Slew Rate
Newall linear encoders will not skip count even at high traverse rates. In its TTL output form, a slew rate of up to 65.6’ (20m)/second can be achieved, while the Absolute encoder version carries a slew rate of up to 196.85’ (60m)/second.

Reliability
Newall linear encoders require no regular cleaning or maintenance, unlike non-contact systems; the linear encoders have no general wear characteristics. There are no LEDs to burn out or glass scales to get scratched or broken. There are no roller bearings, leaf springs or other moving parts to wear out or fail.

Programmable Resolution
Reprogrammable without the need to disassemble the linear encoder from the machine. A connector pin is reserved for the programming function. This feature allows the user to alter the characteristics of the encoder. For example, a linear encoder may have been purchased with a two-micron resolution but subsequently determined that a one-micron is more suitable for the application. The linear encoder can be re-programmed to the desired resolution in the field with the use of a PC.

A Developer’s Kit is available that allows the user to set the linear encoder to virtually any line count, from the same scale and reader head.

Ease of Installation
Installation is simple and forgiving and can be accomplished in a fraction of the time as compared to other linear encoder systems. Even with scale lengths up to 36’ (11m), machined surfaces or backing bars are not needed. For more compact installations, scales less than 20” (508mm) in length need only be supported on one end of the scale. Unlike tape-based systems, they do not rely on a head-to-tape gap height that can vary due to pitch, roll and yaw of a machine’s traveling axis.

Thermal Expansion
The thermal behavior of the linear encoder is an essential criterion for the working accuracy of a machine tool. And thus it is common knowledge that the thermal behavior of the linear encoder should match that of the work piece.

Consequently, a 50°F (10°C) temperature rise can result in a thermal expansion error for glass scales in the order of 40μm over 39.37" (1m) of travel. In practice, it is rare that thermal stability will be achieved within the machine, work piece or linear encoder during normal operation due to rates of thermal behavior and environmental conditions. As a result, errors due to thermal effects are impossible to quantify and may be greater or lower than those theoretically calculated. Such errors are minimized by ensuring that the linear encoder is as matched as possible to both the machine and work piece.

*Spherosyn™ results measured by the Department of Physics University of Hull using strain gauge dilometery with temperature compensation.

Accuracy, Repeatability and Resolution
The laser measurement system used to calibrate all of Newall scales have been calibrated by accredited laboratories providing traceability to UK national standards. The procedures comply with the requirements of British Standard Specification BS5781/International Standard ISO10012-1. The National Physical Laboratory (NPL) calibrates the master standard, certificate number 08A014/9501. All Newall Calibration rigs are traceable back to this NPL standard. The calibration of the Newall scales and reader heads is conducted in a temperature controlled 69.8°F (21°C) environment.

How They Work
To learn more about Newall's Spherosyn™ Technology, click here. For an even more in-depth explanation, download the PDF document containing our linear encoder Technology Guide (975k).

Newall reserves to change specifications to the products without notification and the company accept no liability for claims from any changes.