Measurement of rotational movement of an element, e.g. a table, so that deviations from ideal circular motion can be calculated and used to compensate for the table's motion when it is used to support an object during processing

摘要

Device comprises a measurement body arranged coaxially around the element being measured. The measurement body (1) has two scales (11, 12) that are arranged circumferentially around the rotation axis (A) of the measurement body. The scales are suitable for sampling along two independent, axial and circumferential directions with one scale for sampling in a direction parallel to the rotation axis (A) and with at least three sampling sensors arranged around the circumference of each scale. Six difference components are determined and these can be used with a computer to correct eccentricities when the table is used to support an object during processing. An Independent claim is made for a method for measuring rotational movement of an element such as a round table.