🔍 Key Concepts
• Quadrantal spheres as part of magnetic compass compensation equipment
• Difference between cardinal headings (N, E, S, W) and intercardinal headings (NE, SE, SW, NW)
• Types of compass errors: deviation, heeling error, and errors from vertical soft iron
đź’ Think About
• Ask yourself: when the compass is swung and adjusted, at which headings are the quadrantal spheres mainly used to correct errors?
• Which part of the compass correction setup is normally adjusted first, and which part is specifically for four directions spaced 90° apart?
• Consider what device or corrector is normally used to handle heeling error, and whether that is the same component as the quadrantal spheres.
âś… Before You Answer
• Be clear on the definition of quadrantal error and which headings it mostly affects.
• Separate in your mind: which corrector acts on fore‑and‑aft and athwartships soft iron, and which one deals with heeling.
• Verify which option mentions the group of headings that are 90° apart and would logically be linked to a "quadrantal" correction.