In glass making, inclusion of alien substances invites serious troubles later on.If they are found in a produced glass mass, it is must important to trace where they came from.The detection is made by the following method.
The portion of the glass mass, where the undesirable object lies, is sampled and a ground thin slice is made from it.The slice, with a small hole drilled through the object, is affixed to a copper plate, which serves as the electrode for spark discharge through the hole to determine spectroscopically the constituents of the object.
In the author's experiment with his devised voltage regulator, the above method enabled the origin of intruded substances to be traced whether it was the refractories or the glass raw materials.
