About Lesson
Temporary Adjustments of a Level
Temporary adjustments ensure the level is set up correctly before readings are taken. The adjustments include:
- Setting Up the Level: Place the level on a tripod and roughly level it using the legs.
- Levelling Up: Use the foot screws to precisely level the instrument.
- Three-Screw Method: Adjust two screws in the same direction to center the bubble, then rotate the telescope and adjust the third screw.
- Four-Screw Method: Similar to the three-screw method but with more adjustments for precision.
- Elimination of Parallax: Ensure the image formed by the objective lens lies on the plane of the cross-hairs to avoid parallax. This is achieved by focusing the eyepiece and the objective lens separately.