An engineer’s level has a bubble level that has to be set manually. This means that human error could impact the results given by the equipment. This 19th century technology was used as recently as the 1970s.

The level is used in connection with a grade rod, which is basically a long measuring stick with large numbers that can be read through the eyepiece of the level from a distance. One person holds the rod as the other person looks through the eyepiece of the level to take readings.

When determining the grade of a point, a benchmark is used. A benchmark is a point with a known elevation. The elevation of the point being measured is determined by its difference from the known quantity.

The updated, automatic level has a pendulum inside. When the level reading gets close, the level will take over and set itself. So, any person could set the level and achieve the same setting. This level has a mirror to help set the level if the user has to use the level when the tripod is extended to a height above his or her head. The level also has crosshairs inside the eyepiece to assist the user in taking accurate readings.

This level is typically mounted on a collapsible tripod. The legs are extended or retracted as necessary to account for variations in terrain.

This laser level levels itself internally. A laser receiver is attached to the grade rod and is move up and down the rod until it reaches the reading point. The receiver has both visual and audible cues when it has reached the point.