Cast Bar Porosity Measurement

While I was wandering around in cyberspace the other day I came across an interesting curiosity. I found the abstract of a patent that was just recently granted for a method that I actually did employ to some degree around the mid 80's at Essex Magnet Wire. They described a process that is very similar to one that I came up with using one of the first low cost PC video boards I had ever seen, The Micron-Eye. This was a novel use of a memory chip that could be exposed to light thru a lens and electrically read thus creating a crude sensor much like the solid state video sensors of today. It was black and white of course and very much wider than it was tall but by making three exposures and moving the sample between each one, a composite digital image could be made that wasn't too bad. Look at the word they came up with to replace digital. Wow, what is binarizing anyway. My dictionary didn't know what to make of that.

Here's what I found that got me going.



October 22, 2009

Abstract: An impurity measuring device includes a table (T) on which a sample (S) is to be placed with its fracture surface (h) facing up, an illuminating means (7) for irradiating the fracture surface (h) with light (L) from a plurality of directions, an image sensing means for sensing an image of the fracture surface (h) irradiated with the light (L), continuous tone color image processing means for processing the sensed image into a continuous tone color image, and a binarizing means for binarizing the continuous tone color image through comparison between the result of the continuous tone color image processing and a threshold value. As the fracture surface (h) is irradiated with the light (L) from the plurality of directions, the image obtained by sensing the image of the fracture surface (h) is free from shading or optical irregularities caused by minute irregularities on the fracture surface (h). Therefore, impurities in the sample (S) can be accurately detected from the fracture surface (h) by subjecting the image to the continuous tone color image processing and binarization.


My image showed up porosity. In their case, they might have been seeing porosity too although they related it to impurities in the material. There were no pictures to go along with the abstract that I saw, but I would say they probably did the same thing I did and turned the picture into kind of a weather map of dark colors progressing to red for the areas with the most impurities. When I did mine, the colors showed up on the computer screen but we had no way to print them in color so all I have left is a couple of grey scale printouts from those days.

Here's what mine looked like.