| 摘要 |
A position measuring device for measuring the relative positions of two objects, wherein the two objects are machine components of a processing or working machine or a measuring machine for tools. The graduation of a scale connected to the first object is scanned by a scanning unit connected to the second object. The scale is arranged on a scale carrier so as to be slightly displaceable in a measuring direction. The scale carrier is connected with both ends thereof to fastening elements which, in turn, are rigidly connected to the first object. When the scale, the scale carrier and the workpiece have different thermal expansion, the scale carrier is connected at least at one end thereof to the fastening element with a translatory degree of freedom in measuring direction. The scale is biased at least at one end thereof by a spring element. The spring element is connected to the translatory movable end of the scale carrier. The spring constant of the spring element is selected so that when temperature changes occur the relative change in length of the scale is equal to the relative change in length of the workpiece.
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