What ratio is the most common stadia interval in the United States?

Maximize your readiness for the CDC 3E551 Engineering Journeyman Exam. Use flashcards and multiple choice questions, complete with hints and explanations. Start your journey to success today!

Multiple Choice

What ratio is the most common stadia interval in the United States?

In stadia surveying, distance is obtained by multiplying the reading difference between the upper and lower stadia hairs by a constant called the stadia interval. In United States practice, that constant is 1:100, meaning each unit of staff difference yields about 100 units of horizontal distance (when staff readings are in feet, the distance comes out in feet). This 1:100 factor comes from the instrument’s optical setup and makes calculations simple and consistent across field work. Other ratios would reflect different instrument calibrations and are not the standard used, which is why 1:100 is the best answer.

In stadia surveying, distance is obtained by multiplying the reading difference between the upper and lower stadia hairs by a constant called the stadia interval. In United States practice, that constant is 1:100, meaning each unit of staff difference yields about 100 units of horizontal distance (when staff readings are in feet, the distance comes out in feet). This 1:100 factor comes from the instrument’s optical setup and makes calculations simple and consistent across field work. Other ratios would reflect different instrument calibrations and are not the standard used, which is why 1:100 is the best answer.

More practice questions