When is it necessary to check the level of a spirit?

The spirit level is a tool that is used to measure if a surface islevel. It is also used to check for vertical motion of objects.

The spirit level is a metal strip with a series of rectangular hinge pins at each end. When the strip is placed against a surface, the pins will rest at the same level if the surface is level. If the surface is not level, the pins will be offset, indicating that the surface is not level.

The spirit level can be used to check for vertical movement of objects.