We must gauge the diameter of wire first. 我們必須先測量電線的直徑。
A unit of length equal to one thousandth(10-3) of an inch(0.0254 millimeter), used, for example, to specify the diameter of wire or the thickness of materials sold in sheets. 密耳長度單位,等於一英寸的千分之一(10-3)(0.