empty weight of equipment

例句：

1. 1.The engineer calculated the empty weight of the new machine before installation.
   工程师在安装前计算了新机器的空重。
2. 2. The empty weight of the package is important for calculating shipping costs.
   包装的空重对于计算运费很重要。
3. 3.The empty weight of the container was too heavy, which made it difficult to load onto the ship.
   集装箱的空重太重，装载到船上很困难。