Division error
When using devices (e.g. dividing head ) to measure individual angles, the built-in pitch circles are always assumed to be free of errors. This requirement is not strictly true; even the best pitch circles are not completely free of errors. In general, it is not necessary to check the pitch circles for the angle determinations required in technology. For exact measurements, however, the pitch errors must be taken into account.
Item error
The individual division error of a division is the difference between the actual value and the nominal value of a division interval.
Sum division error
The total division error is the difference between the actual value and the nominal value of the series of division intervals formed by the same division. It is therefore equal to the sum of the individual division errors of the division intervals contained in the sequence.
Division jump
The division jump is the difference between two successive division intervals. It therefore corresponds to the difference between two successive individual division errors.
Group division error
The group error of a division or group division error is the difference between the actual value and the setpoint of a group of consecutive division intervals. It is equal to the sum of the individual division errors of the division intervals belonging to the group or the difference between the total division errors belonging to the delimiting graduation marks.
Total error of a division
The total error of a division is the largest group division error that exists for any group of consecutive division intervals. It is equal to the deflection width of the cumulative error curve.
literature
- Kurt Räntsch: Basics of technical angle measurement. 1st edition. Carl Hanser Verlag, Munich 1952.
- VDE / VDI 2605: Circular divisions and flat angles; Basic terms for angle dimensions, angle measurements, angle standards and their errors. January 1973.