Method for calibrating equipment for detecting impurities in transparent material
AssigneeSemyre Photonic Systems AB
InventorGöran Åsemyr
Life of this patent
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Abstract
Equipment for detecting impurities in transparent material comprising a light source to illuminate the material, a camera to detect light transmitted through the material and signal-processing apparatus for processing and analysing signals from the camera representing the light transmission through the material. This type of equipment is calibrated by dark areas being displayed on a film of transparent material (22, 24, 26) and the actual sizes (30) of the areas being determined. The sizes of the dark areas are then determined using the detecting equipment (34) and in this way determined sizes are compared with actual sizes (36) for calibration of the detecting equipment (38).
Claims6
A method for calibrating equipment for detecting impurities in transparent material, said detecting equipment including a light source to illuminate the material, a camera to detect light transmitted through the material and a signal processing apparatus for processing and analyzing signals from the camera representing the light transmission through the material, said method comprising the steps of:
- (a) displaying dark areas on a film of transparent material with a predetermined size larger than sizes desired for the calibration;
- (b) subsequent to step (a), reducing the dark areas to the desired sizes for the calibration using a repro- or microfilm camera to form a calibration film;
- (c) determining the actual sizes of the reduced dark areas;
- (d) determining the size of the dark areas on the calibration film using the detecting equipment;
- and
- (e) comparing the sizes of the dark areas of step (d) and the actual sizes of the dark areas of step (c) for calibration of the detecting equipment.
Dependencies are inferred from the claim text.