Maintenance Protocols Flashcards

How can a crew check the optical plummet on a rotating tribrach?

Answer: Mark the ground point, rotate the tribrach in 120° steps, and see if the crosshair stays on the mark

If the plummet line of sight is out of adjustment, it traces a circle around the mark as the tribrach rotates.

If the wrong prism constant is entered in the total station, what type of error results?

Answer: A systematic constant error in every measured distance

A wrong prism offset adds the same amount to each slope distance, creating a systematic bias.

Where are EDM instruments commonly checked for distance accuracy in the United States?

Answer: On an NGS calibration baseline (CBL)

NGS calibration baselines provide precisely known distances for checking EDM constant and scale errors.

What is the main purpose of a written maintenance log for each instrument?

Answer: To document calibrations, repairs, and checks so accuracy can be traced and defended

A maintenance log shows when an instrument was last checked or adjusted, which supports the quality of the survey data.

How should lithium-ion instrument batteries be stored for long periods?

Answer: Partially charged (about 40-60%) in a cool, dry place

Partial charge and cool storage slow lithium-ion aging and capacity loss.

While driving between sites, how should a total station be transported?

Answer: Inside its padded case, secured so it cannot slide or bounce

The fitted case protects against vibration and shock that can knock the instrument out of adjustment.

What does horizontal collimation error cause when observing the same point in both faces?

Answer: Horizontal readings that do not differ by exactly 180°

Collimation error makes the line of sight not perpendicular to the trunnion axis, so face-left and face-right horizontal readings are not exactly 180° apart.