CPP50121 Diploma of Surveying · Plot 7 of 10 · CPPSSI5054
Point Scale Factor k — MGA2020 Zone 50
393 000 m
Scale factor k vs easting across Zone 50 (CM = 117°E, E = 500 000 m). Minimum k₀ = 0.9996 at CM. Perth (E ≈ 393 000) has k ≈ 0.9999. Zone edges k ≈ 1.0010. Formula: k ≈ k₀ · [1 + (E−500000)² / (2·R²·k₀²)]
Source: CPPSSI5054 Study Guide · k₀ = 0.9996, R = 6 372 000 m