Equipment Operation Flashcards

How is the two-peg test used?

Answer: To determine whether a level's line of sight is horizontal when the bubble is centered

The two-peg test compares elevation differences from a midpoint setup and an offset setup to detect collimation error in a level.

A total station's EDM requires temperature and pressure input. Why?

Answer: The atmosphere changes the speed of light, so a ppm correction is applied to distances

Temperature and pressure change the refractive index of air, and the instrument applies a ppm scale correction to distances.

What does the dual-axis compensator in a total station correct?

Answer: Small residual tilts of the vertical axis that affect horizontal and vertical angles

The compensator senses small remaining tilt of the vertical axis and corrects angle readings for it.

How is parallax eliminated before taking readings through a telescope?

Answer: By focusing the eyepiece on the crosshairs first, then focusing the objective on the target

Focusing the crosshairs with the eyepiece and then the target with the objective makes the image and crosshairs lie in the same plane.

In reflectorless mode, which situation is most likely to cause a wrong distance?

Answer: Aiming at the edge of a building where the laser footprint hits two surfaces

When the beam footprint falls partly on a near surface and partly on a far one, the returned distance can be a mix or come from the wrong surface.

Which practice best protects a total station during transport between setups?

Answer: Removing it from the tripod and carrying it in its case, especially in a vehicle

Transporting the instrument in its case prevents shock and vibration damage, especially in vehicles or rough terrain.

When a tripod is set on hot asphalt, what is a common problem?

Answer: The tripod feet can slowly sink, causing the instrument to drift off level

Soft or heated surfaces let tripod legs settle, so level and centering should be checked during observations.