CPP50121 Diploma of Surveying · Plot 8 of 10 · CPPSSI5054

Grid Convergence γ — Zone 50

Easting E (m)393 000 m

Latitude (°S)32.0°S

Left: compass rose showing Grid North (blue) vs True North (red) — the angle between them is γ. Right: γ across Zone 50 for the selected latitude. γ = 0 at the CM (E = 500 000 m). West of CM → γ negative (Perth ≈ −0°52′). Relationship: True bearing = Grid bearing + γ.

Source: CPPSSI5054 Study Guide · γ ≈ (E−500000)·tan(φ)/(R·k₀)