变幅杆厚度
对于矩形变幅杆，指垂直于螺柱轴线方向的最小尺寸（即既非变幅杆长度也非变幅杆宽度的那个尺寸）。若未指明位置，则假定在变幅杆端面处测量。
示例：对于端面尺寸为 125 mm x 50 mm 的变幅杆，其宽度为 125 mm，厚度为 50 mm。
Horn thickness
For a rectangular horn, the smallest dimension transverse to the stud axis (i.e., that dimension which is neither the horn length nor horn width). If no location is specified, the thickness is assumed to be measured at the horn face.
Example: in a horn whose face dimensions are 125 mm x 50 mm, the width is 125 mm and the thickness is 50 mm.