A SIMPLE INSTRUMENT FOR MEASURING EDGE ANGLES USING A LIGHT SECTIONING METHOD

A simple instrument for measuring edge angles is proposed, in which a light sectioning method is introduced. It has the advantage of simplic ity, and consequently provides easy operation and an inexpensive instr ument. A specimen is tilted in parallel planar laser beams. V-shaped l ines are drawn by the laser beams on both sides of the specimen and ar e observed through a microscope. The tilt angle of the specimen can al so be measured by the parallel planar laser beams. The edge angle can be calculated from the observed apex angle of the V-shaped lines and t he tilt angle of the specimen. Measurement error factors are analysed and the measurement result is compensated. The measurement error of th e instrument is estimated to be about 0.08 degrees an average and 0.12 degrees in variance after compensation. Although the instrument is ca pable of measuring the edge angles of many kinds of object, it is most suitable for measuring the edge angles of knives. The accuracy of thi s novel instrument may be sufficient for the quality control of knives .