To achieve 2nd Order accuracy, what is the required vertical accuracy specification for 1 km of double-run leveling without a micrometer?

To achieve 2nd Order accuracy, what is the required vertical accuracy specification for 1 km of double-run leveling without a micrometer?

• A. 0.2 mm
• B. 1.5 mm
• C. 2.0 mm
• D. 0.8 mm

Answer: (D)

In leveling, the vertical accuracy for a job is described as how many millimeters of misclosure per kilometer of work. For second-order leveling, and when you don’t have a micrometer on the staff, the standard target is about 0.8 mm of vertical misclosure per kilometer of double-run leveling. The double-run setup—going from point to point and then back—helps cancel out much of the random and systematic error, so a slightly tighter per-kilometer tolerance is acceptable compared to a single direction. This is why 0.8 mm per kilometer is the appropriate specification for 1 km of double-run leveling without a micrometer. Values like 0.2 mm would be far too tight for this setup, while 1.5 mm or 2.0 mm would be looser than typical second-order requirements without high-precision instruments.

In leveling, the vertical accuracy for a job is described as how many millimeters of misclosure per kilometer of work. For second-order leveling, and when you don’t have a micrometer on the staff, the standard target is about 0.8 mm of vertical misclosure per kilometer of double-run leveling. The double-run setup—going from point to point and then back—helps cancel out much of the random and systematic error, so a slightly tighter per-kilometer tolerance is acceptable compared to a single direction. This is why 0.8 mm per kilometer is the appropriate specification for 1 km of double-run leveling without a micrometer. Values like 0.2 mm would be far too tight for this setup, while 1.5 mm or 2.0 mm would be looser than typical second-order requirements without high-precision instruments.