摘要 |
The present invention provides an apparatus for measuring the straightness, the deviation from the straightness or bending of the surface of a ferromagnetic bar, such as a (part of a) railroad rail, comprising: a first end part, a second end part at a distance from the first end part, wherein the first and the second end parts are placed over the rail for measuring, a magnetic sensor that can be moved between the first and the second end part, and compensation means to compensate for remanent magnetic in the ferromagnetic material of the bar. |