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A leveling rod is a surveying tool used to take elevation measurements for the purpose of profiling a section of terrain. There are a number of basic designs available, including versions for optical and digital sighting and record keeping. Surveying supply companies typically sell leveling rods and accessories like cases, replacement components, and other surveying tools. Engineers, surveyors, and members of other professions that need to perform surveys receive instruction in the use of a leveling rod as part of their education.
This tool is also known as a level staff, a reference to the original design, which was simply a tall staff with measurement markings. The surveyor could place the staff in a location with a landmark of known height, perform a sighting for reference, and then move the staff to take a series of sightings, looping back to the original site or another known reference for confirmation at the end. While older level staffs are still in use, modern designs are more flexible and tend to be easier to use.
It is common for a leveling rod to fold up, break down, or collapse into itself. This makes it much easier to handle and transport when it is not in use. The surveyor can take the leveling rod out at the site, assemble it, and lock the components in place to make sure they will not slide while taking measurements. In the case of an optical device, the surveyor has a small target to use as a marker on the rod while taking sightings. She works with a partner to move the target and record data.
Digital rods can take automatic readings. These have a number of advantages, including the ability to be used solo, instead of with a partner. They are also faster and can be more reliable. Operator errors are limited and the surveyor cannot mistranscribe a number or make a similar error because the rod stores the data automatically. It can also record data about the conditions and automatically make adjustments, if necessary, to address atmospheric conditions that might impact measurements.
When a surveyor selects a leveling rod, it can be helpful to test some models. While in training, surveyors usually have an opportunity to work with a variety of equipment and may develop a preference or get a recommendation from an instructor. Some manufacturers will also allow surveyors to use their equipment on a trial basis with a generous return policy.