Level Loop Closure Checker
Enter the rise-and-fall readings and distances around a closed level loop to get the misclose, compare it against a project-selected C√K guideline grouping and see an advisory distance-proportional distribution — with the full working shown for every step.
Free advisory field tool — every result is computed in your browser from the inputs you provide and is advisory and unverified, not for survey deliverables. Where a published guideline applies, results only ever read “within guideline” or “exceeds guideline — review”. The full working is shown for every calculation so each step can be re-checked. Registered surveyor confirmation required before reliance.
Loop setups
Enter the observed rise (+) or fall (−) in metres and the levelled distance in kilometres for each setup, in order around the closed loop. The loop sum should come back to zero.
The 2, 6 and 12 mm√K options are project-selected guideline groupings from the ICSM Guideline for Control Surveys by Differential Levelling v2.2, Tables 3 and 4. Use only the grouping named by your project specification or controlling instruction. They are not universal survey orders, and this tool does not infer jurisdictional applicability.
Loop closure
Select the grouping named by the project specification, then enter at least two complete setups (and a positive C) to compute the loop misclose. Results, the C√K comparison and the full working appear here.
Choose only the C√K grouping specified for the project or controlling instruction. The options are guideline groupings, not universal survey orders, and this tool does not infer jurisdictional applicability.
Advisory output — confirm independently before reliance.
Safety & scope
SurveyMarkup helps prepare and review working information. Every professional decision remains with the registered surveyor, and original data and final outputs require qualified review.
Assistance only - professional review remains required.