Spire test is used for the adjustment of
- ALine of sight
- BHorizontal axisCorrect
- CVertical axis
- DAdjustment of altitude bubble
Solution
Concept
Spire test
Step-by-step solution
1. The spire test checks that the horizontal axis is perpendicular to the vertical axis. 2. It is the test (and adjustment) for the horizontal axis.
Explanation
Spire test is the test used to make the horizontal axis perpendicular to the vertical axis. The telescope is pointed at a high object (spire), depressed to a point on the ground and the readings are compared on both faces.
Shortcut
Spire test = horizontal axis.
Common mistake
Choosing the line of sight.
Correct answer: B) Horizontal axis