水準器

The primary tools used for leveling are a level and a level rod.

A level consists of a telescope for focusing on the object to be sighted and a spirit level and leveling screws for leveling the instrument. 

Automatic levels and electronic digital levels are generally used for accurate leveling. 

The automatic level fixed on the tripod, after being roughly leveled manually, uses a suspended compensator for automatic and precise leveling of the instrument.

An electronic digital level also performs automatic leveling and is designed to take readings electronically by sighting the bar codes provided on the level rod. 

A level rod is a graduated rod made of wood, fiberglass, or metal that comes in one or more pieces. 

The graduations start from zero at the bottom and are represented in feet or meters, depending on the region. 

The readings on the level rod are sighted and read through the level's telescope.

Sometimes, a sliding vernier scale placed on the rod or an optical micrometer mounted on the telescope helps take readings smaller than the rod's least count.