Differential leveling is the method of measuring which?

• A. The difference in elevation between two or more points using a graduated staff.
• B. The difference in horizontal distances between points.
• C. The change in elevation calculated from a single height.
• D. The slope of a line using a clinometer.

Answer: (A)

Differential leveling measures how much one point differs in elevation from another by reading vertical staff graduations through a level instrument. You set up the level, take a backsight reading on a staff at a known point to establish the instrument’s height, then take a fore sight reading on a staff at the next point. The difference between the fore sight and backsight readings (accounting for the instrument height) gives the elevation change between the two points. By moving along the line and repeating this process, you build elevations tied to a benchmark. This method focuses on vertical differences and does not measure horizontal distance, slope with a clinometer, or rely on a single height.