How the books are made
Each run starts from invented ground levels in whole millimeters or hundredths of a foot. The readings come from those levels and from where the level is set up, so every reading fits on a real staff and every check balances on the key. Sights stay within 90 m (300 ft), the longest the WSDOT highway surveying manual allows. A misclosure is added only when a question asks for one, and it is always well inside or well outside the stated limit, never on the edge. The rods are drawn here, with every hair on a band edge or the middle of a band.
A worked example
In set HPC234 (intro surveying, meters), the first book starts on BM 1 at 62.000 m. The backsight of 2.600 gives an HI of 64.600 m. The intermediate sight of 2.536 on A puts A at 64.600 − 2.536 = 62.064 m, and the foresight of 3.172 puts TP 1 at 61.428 m. Two more setups bring the run to BM 2 at 59.187 m. The check: Σ BS = 5.281, Σ FS = 8.094, and 5.281 − 8.094 = −2.813, the same as 59.187 − 62.000. Open set HPC234
What each level asks
| Level | Books | Also |
|---|---|---|
| FFA / high school ag mechanics | Height of instrument books in feet, as in the FFA team activity | Rod reading to 0.01 ft, stadia distance, percent slope and slope class on the Oklahoma, North Georgia or South Georgia land judging card, closing a loop, a missing reading |
| College intro surveying | Height of instrument and rise and fall, with intermediate sights, in meters or feet | Misclosure against 12 mm × √K or 0.05 ft × √M, adjusting, profiles, stadia and gradient |
| Civil engineering diploma | Adds staff readings taken upside down (ceilings, soffits, beams) | Misclosure against 5 mm × √N, loop adjustment, smudged entries in reduced books |
Questions
What is the difference between the rise and fall method and the height of instrument method?
Both start from a benchmark. The height of instrument method adds the backsight to get the level of the line of sight, then takes every reading from it. The rise and fall method compares each reading with the one before it. Rise and fall takes longer, but its checks cover the intermediate sights too.
How do you do the arithmetic check in leveling?
Add up the backsights and the foresights, leaving out intermediate sights. Σ BS − Σ FS must equal the last reduced level minus the first. In a rise and fall book, Σ rise − Σ fall must match as well. The check proves the arithmetic, not the field work: only closing on a known benchmark does that.
How do you book an inverted staff reading?
When the staff is held upside down against a ceiling or the underside of a bridge, book the reading with a minus sign. The usual rules then work: RL = HI − (−1.250) = HI + 1.250, so the point comes out above the line of sight.
What is the allowable misclosure in leveling?
It depends on the specification. US third order leveling allows 12 mm × √K, with K in kilometers, or 0.05 ft × √M with M in miles. Some course workbooks use 5 mm × √N, where N is the number of setups. Each question here states its rule, and every misclosure is well inside or well outside it.
How do you distribute the misclosure?
If the misclosure is acceptable, give each setup an equal share with the opposite sign. The point after the third of five setups gets three fifths of the total correction. The closing benchmark gets all of it, so it lands on its known level.
How do you read a leveling rod and find the stadia distance?
Find the number just below the crosshair and count the bands up to the hair: 0.01 ft bands on an engineer's rod, 1 cm bands on a metric E staff. For distance, take the bottom stadia hair from the top one and multiply by 100: 1.240 − 0.910 = 0.330, so the staff is 33 m away.
Sources, checked October 25, 2026: NPTEL, Surveying (J. K. Ghosh, IIT Roorkee), lessons 13 and 14: reduction of levels, arithmetic checks, level nets and profile leveling; Transportation Information Center (Wisconsin), Basic Surveying Manual (PDF): level rods, booking readings, closing the circuit; Federal Geodetic Control Committee, Standards and Specifications for Geodetic Control Networks (September 1984, PDF); WSDOT Highway Surveying Manual M 22-97, chapter 10, Differential Leveling (January 2005, PDF); Soil Engineering Practical Workbook (Malaysian polytechnic, November 2021), 1.6.3 and 1.6.4; MADE EASY, Level field book (July 2024): inverted staff readings; Spectra Precision AL auto level user guide (PDF, 2024): stadia constant 100; Georgia FFA Agricultural Technical and Equipment ID CDE information sheet 2021-2022 (PDF) and 2024-2025 (PDF); Land Judging in Oklahoma, 4-H member's guide (PDF), slope classes p. 3 and land classes p. 6; Georgia FFA Land Judging Contest Guide, revised 2024 (PDF), slope categories pp. 6-7 and best land class p. 17.