Instrument height (also called Height of Instrument or HI) is the elevation of the line of sight of a leveling instrument at a given setup location. It is calculated by adding the backsight rod reading to the known benchmark elevation. All foresight elevations are determined by subtracting rod readings from the HI.
Log grade shots, verify elevations, and generate inspector-ready field reports from your phone. No office work required.
Get started free →