What the component does
The scale places a length reference close to the measured motion. Incremental and absolute patterns support different startup and referencing methods.
Linear Position Measurement
Measure carriage travel relative to a reference scale instead of relying solely on screw or motor rotation.
Where the component works
Reader travels along a fixed scale
- Scale fixed along the travel axis
- Moving carriage
- Readhead beside the scale
This arrangement fixes the scale and moves the reader; some machines use the reverse arrangement.
Match the pattern to the readout
- Periodic incremental divisions
- Illustrative absolute coding track
- Reference and track registration
These are simplified pattern examples, not production encoding artwork or a universal absolute-code format.
How the system works together
Transmissive readers place illumination and detection across the scale; reflective readers use the returned light. Coating and readhead geometry must suit the chosen path.
What an unsuitable choice changes
Thermal expansion, mounting stress and an offset between the scale axis and measurement line can cause errors beyond the graduation itself.
Components for this application
Incremental Linear Encoder Scales
Periodic scale tracks with reference marks for homing.
Absolute Linear Encoder Scales
Position-coded scales matched to a specified decoder.
Glass Linear Scales
Choose between incremental and absolute glass scale configurations.
Other relevant products and configurations
Transmissive Glass Encoder Scales
Glass scales for a readhead with optical access to both sides.
Reflective Glass Encoder Scales
Reflective patterns for compatible readheads on one side of the scale.
Chrome Amplitude Gratings
Custom periodic glass patterns for a compatible optical readhead design.
Principles and selection details
System context
A patterned scale is mounted along the measurement axis and read as the carriage moves. Incremental scales provide repeated intervals; absolute scales carry a position code. Typical integration tasks include stage travel measurement, machine-axis feedback and coordinate measurement.
Selection considerations
The physical pitch is not necessarily the reported system resolution because interpolation may subdivide each period. Total travel accuracy also depends on cumulative pitch error, glass expansion, mounting stress and alignment of the measuring axis.
Machine axes, microscopes and measuring stages
A scale can be used to close a positioning loop or independently measure carriage travel. Keep active length separate from overall glass length, and place the measuring reference near the motion of interest where the mechanical design permits.
Related applications
Planning your project
Glass linear scales provide periodic or absolute position references along a measuring axis.
State overall glass length, active travel, pitch, reference position and mounting datum separately.
Is scale pitch the smallest displayed increment?
Interpolation may produce a smaller output increment. Physical pitch, reported increment and full-travel accuracy are different specifications.