Optical geometry measurement systems for reinforcing steel
The devices are used for automated geometric measurement in quality assurance and factory testing of hot and cold rolled reinforcing steel with two, three, four or six rows of ribs.Both high-grip and intended material can be measured.The measurement is carried out according to standards according to German, European and most international standards.
For the measurement, the samples must have a length of between 200 and 500 mm.The test bar is clamped horizontally in a three-jaw chuck and, depending on the measured variable, illuminated with high-contrast or transmitted light. The test object is optically captured from different angles by two to three high-resolution CMOS black and white cameras and displayed in a window on the computer monitor
A computer and an image processing unit digitize the respective image. The measuring principle is based on the search of black and white transitions, where the object boundaries are determined by means of a gradient method from the gray levels.
The instrument is calibrated by two certified calibration rods of different diameters. Calibration is automatic and can be repeated at any time. The rib measurement system determines the following measurements:
- Rod cross-section and diameter
- Rib height at the centre and at the quarter-points
- Centre distance of the ribs
- Head width and foot width of the ribs
- Inclination of the ribs to the rod axis
- Distance between rows of ribs
- Specific rib area in several Norms
- Height and width of longitudinal ribs