What is an Arithmetic Check in differential leveling?

• A. A method of checking the total area surveyed
• B. A verification of the sums of backsights and foresights
• C. A calculation to verify the lengths of field measurements
• D. An assessment of the number of instruments used

Answer: (B)

An arithmetic check in differential leveling involves the verification of the sums of backsights and foresights. This process is crucial for ensuring that the leveling data collected is accurate and reliable. In differential leveling, backsights are readings taken from a level instrument to a known benchmark or point of elevation, while foresights are measurements taken to determine the height of the instrument relative to a point of interest.

By totaling the backsights and foresights, surveyors can confirm that their calculations are consistent with the expected differences in elevation. The sum of the backsights should equal the sum of the foresights plus the change in elevation from the benchmark, allowing surveyors to identify any discrepancies that could indicate errors in measurement or data entry. This arithmetic check is an essential part of data validation in the leveling process, ensuring that the elevations calculated from the various points surveyed are accurate and can be trusted for further analysis and application.