测径器

例句：

1. 1. We need to use a ruler to measure the diameter of the pipe.
   我们需要使用直尺来测量管道的直径。
2. 2. The engineer used a caliper to measure the thickness of the metal sheet.
   工程师使用卡尺来测量金属板材的厚度。
3. 3. The carpenter measured the width of the door with a tape measure.
   木匠用卷尺测量门的宽度。