Levelling Calculations
Compute reduced levels using Height of Instrument and Rise & Fall methods, with automatic change-point handling and arithmetic checks.
Levelling Observations
Enter a known starting reduced level and the staff readings. Use BS for a backsight, FS for a foresight and IS for an intermediate sight. At a change point, enter the FS in one row and the BS in the following row using the same point name.
Starting Benchmark
Computation Settings
Staff readings must be non-negative. A row may contain only one observation type. Rows are processed in field-book order.
Staff Observations
| Obs. | Point | BS | IS | FS | Remark | Remove |
|---|---|---|---|---|---|---|
| 1 | ||||||
| 2 | ||||||
| 3 | ||||||
| 4 | ||||||
| 5 |
Recommended booking order for a change point: FS on the old setup, then BS on the same CP from the new setup. The calculator detects that transition and carries the RL forward correctly.
Levelling Method Reference
The calculator reports both standard methods from the same field observations and checks their arithmetic agreement.
RL = HI − staff reading
Fall = current reading − previous reading