Method and device for determining straightness errors

The present invention refers to a method and a device for determining straightness errors designed to check the errors of large pieces, such as machine-tool frames. The method for determining straightness errors consists of dividing the length of the profile to be checked into equal segments and measuring the distances from the second end of each segment to the polar axis. According to the invention, the method uses a straight, ideal line as the polar axis. This line is created by extending the first of the equal segments that the profile to be checked was divided into, and consists of measuring the distances from the second end of each of the segments that the profile to be checked was divided into to the straight line formed by extending the previous segment. According to the invention, the device is equipped with a linear support (1) and a displacement transducer (2) which is mounted at the other end of the support (1) and can be adjusted along the support. An adjustable tracer (3) is mounted at the other end of the support (1) and can also be adjusted along it, and a fixed tracer (4) is positioned in the middle of the distance between the adjustable tracer (3) and the displacement transducer (2).