Method and device for measuring a folding angle of a sheet (6,25,26) in a folding machine, whereby a number of distances are measured in a plane (28) that crosses the sheet (6,25,26) and the element (4,24,7), whereby a distance profile (19) of the measured distances is determined, and whereby the folding angle (A) of the sheet (6,25,26) is determined as a function of the angle (B,B1,B2) between the sheet (6,25,26) and the element (4,24,7).
A method and device for determining the length (b) of at least one of two legs (13, 14), of a workpiece (12) bent toward each other at a bending angle (.beta.) requires location of the workpiece (12) in a defined position. The position of the bending angle vertex (S) and the position of the end (E) of the leg (13, 14) to be measured are determined. Based on the position of the bending angle vertex (S) and of the end (E), the length (b) is calculated as the distance between the bending angle vertex (S) and the end (E). The measuring apparatus includes a system serving to determine the position of the bending angle vertex (S), a unit serving to determine the position of the end (E) and an evaluation unit which, based on the position of the bending angle vertex (S) and of the end (E), calculates the length (b) as the distance between the bending angle vertex (S) and the end (E).
