Quality Inspection Flashcards

A closed traverse has a perimeter of 5,000 ft and a linear misclosure of 0.25 ft. What is its relative precision?

Answer: 1:20,000

Relative precision equals misclosure divided by perimeter: 0.25/5,000 = 1:20,000.

What should the interior angles of a closed six-sided traverse sum to?

Answer: 720°

The sum of interior angles is (n − 2) × 180°, so (6 − 2) × 180° = 720°.

The compass (Bowditch) rule distributes traverse misclosure in proportion to what?

Answer: The length of each course relative to the perimeter

The compass rule corrects latitudes and departures by each course length divided by the total traverse length.

Why are leveling closure tolerances usually expressed as a constant times the square root of the distance?

Answer: Random errors accumulate in proportion to the square root of the number of setups or distance

Random errors propagate as the square root of the number of observations, which is proportional to distance.

A steel tape used in hot weather without correction produces which type of error?

Answer: Systematic error

Thermal expansion affects every measurement in the same direction and can be computed and corrected.

What arithmetic check verifies a differential leveling field book page?

Answer: Sum of backsights minus sum of foresights equals the change in elevation

ΣBS − ΣFS must equal the ending elevation minus the starting elevation for the arithmetic to be correct.

What is the most effective way to detect a blunder in a field measurement?

Answer: Taking independent redundant measurements and comparing them

Blunders show up as disagreement between independent repeat measurements, not through adjustment.