| Accuracy |
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The accuracy of rotary encoders is influenced
mainly by: |
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The directional
deviation of the radial grating. |
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The eccentricity of the
graduated disk to the bearing. |
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The radial deviation of the
bearing. |
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The error resulting from the
connection with the rotor couplings. On rotary encoders with
stator coupling this error lies within the system accuracy. |
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The interpolation deviation
during signal processing in the integrated or external
interpolation and digitizing electronics. |
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For incremental rotary encoders with line counts up
to 5000:
The extreme values of directional deviation at 20 °C ambient
temperature and slow speed (scanning frequency between 1 kHz and 2
kHz) lie within
| ± |
18°
mech. · 3600 |
[angular
seconds] |
 |
| Line count z |
| ± |
1 |
grating
periods. |
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| 20 |
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ROD rotary encoders with line counts of 6000 to
10000 have a system accuracy of ± 12 angular seconds. |
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Circular
graduations of
incremental rotary encoders |
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The accuracy of the absolute position values from absolute
rotary encoders is given in the specifications for each model.
For absolute rotary encoders with additional incremental signals,
the accuracy depends on the line count: |
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| Line count |
Accuracy |
| 512 |
± 60 angular
seconds |
| 2048 |
± 20 angular
seconds |
| 8192 |
± 10 angular
seconds |
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The above accuracy data refer to incremental
measuring signals at an ambient temperature of 20 °C (68 °F) and
at slow speed. |
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Circular
graduations of
absolute rotary encoders |
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