An Abney level is a hand-held surveying tool used to measure slope and grade. The user looks through the sighting tube at a target while adjusting a built-in spirit level. Once the bubble is centered, they read the angle of slope directly from the scale arc. In highway and off-road trail construction, it helps engineers check grade changes to ensure proper water drainage.
Mechanic Glossary
Abney Level
A hand-held surveying instrument that combines a sighting tube, a spirit level, and a graduated arc to measure slope angles and elevations.
Frequently Asked Questions
Look through the sighting tube at a target, adjust the index arm until the level bubble is centered in the view, and read the angle on the scale.
Measuring bank slopes, checking ditches for proper runoff angles, and estimating road grades.
It was invented by William de Wiveleslie Abney in the 1870s for surveying and topographic mapping.