How do you adjust a leveling circuit with multiple loops?

Multi-loop leveling adjustment: calculate misclosure for each loop (sum of rises minus falls). If misclosure exceeds allowable (typically 12 mm x sqrt(k) for ordinary leveling, k in km), re-level that section. For acceptable misclosures, adjust using least squares or approximate methods. Distribute misclosure proportionally to number of setups or distance. For complex networks, observation equations relate measured height differences to unknown elevations at stations. Normal equations solved by matrix methods. Adjusted elevations satisfy all observations optimally. Software like STAR*NET automates network adjustments.