Level / RL Calculator
A complete level book in the browser: reduced levels by the height-of-instrument or rise-and-fall method, the arithmetic checks worked out for you, closing error against the closing benchmark, and the correction distributed over the setups.
Leave a cell empty when there is no reading. A line with both a back sight and a fore sight is a change point. A negative staff reading is treated as an inverted staff, exactly as in a written level book.
Both methods, both checks. Height of instrument: HI = RL + BS, and every RL = HI − (IS or FS). Rise and fall: each reading is compared with the one before it on the same setup, giving a rise or a fall. The classic checks are printed with the result — ΣBS − ΣFS must equal the last RL minus the first, and in the rise-and-fall method it must also equal Σrise − Σfall. If any of those disagree the tool says so instead of quietly presenting the levels. Closing error is the computed RL of the last point minus its known RL, and the allowable figure is the familiar C√K millimetres with C and the route length K as you enter them — a common specification, but always check what your own project demands. The correction, when applied, is distributed in proportion to the number of setups, which is the usual practice for a simple line of levels.
What the Level / RL Calculator does, and how
What does the BTPL Level / RL Calculator do?
The BTPL Level / RL Calculator is a complete level book in the browser. It reduces staff readings to reduced levels by either the height-of-instrument or the rise-and-fall method, works out the arithmetic checks, computes the closing error against the closing benchmark, compares it with the allowable misclosure, and distributes the correction over the setups.
Does it handle inverted staff readings and the allowable misclosure?
The BTPL Level / RL Calculator supports inverted staff readings (for soffits and overheads) in both methods, and the allowable misclosure is worked out as C√K millimetres, with C set by you and the route length K taken from the distances entered in the level book.
Is my level book uploaded anywhere?
Nothing is uploaded: the BTPL Level / RL Calculator computes everything in your own browser, and the figures you enter are never sent to a server. It keeps working without an internet connection once the page has loaded.
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