Glasses are heated in the process of production and made into various shapes. If there isn't enough Annealing treatment, invisible distortion may arise at inside of glasses. If the distortion still remains in the block, it would be break very easily even by a small damage. In extreme case, the glasses might deformed by curving spontaneously and crack might be caused due to heterogeneousness. By Distortion Tester you can find out distortion in insufficient Annealing Treatment products easily.
*Annealing : Process of heating glasses up to sufficient temperature, keep that temperature for curtain period, then cooling it very slowly. Purpose of this process is, get rid of residual stress, prevent decrease of hardness, machinability improvement, improving cold workability and adjustment of crystallized structure.
There is a scale 0° to 100° both right and left on the rotating frame. Position of 0° is normal state , and at the position of 90° most thick distortion color will appear.
At the time of inspection, at first you will find out the point of non-defective limit. Based on that point, you will use scales at rotary frame. If you can find out distortion color at lower point than the point where limit of non-defective product start to show coloring, you can judge that product has not enough Annealing Process.
If Annealing process is done enough, distortion will not show up. The more Annealing process were insufficient, the more distortion color were thick. Distortion color will differ a bit according to specimen.
By Microscope Type TS-9N, you can observe distortion on tiny samples clearly which would hard to find out by naked eyes by combining with high magnification Stereo Binocular.
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