Definition

Noun: A compact surveying instrument that combines a spirit level with a telescopic sight; it is used to measure vertical angles or the slope of a line from the observer to a target point.

Usage

The Abney level is used by surveyors, foresters, and engineers for measuring angles of elevation or depression in the field. * The forester used an Abney level to determine the height of the tree. * Accurate measurement of the hill's slope was obtained with an Abney level.

Advanced Usage

• To take an Abney level reading: This phrase describes the action of using the instrument.
  • The surveyor stopped to take an Abney level reading before proceeding along the traverse.

Variants and Related Words

• Clinometer: (Noun) Another name for an instrument that measures angles of slope, elevation, or depression. An Abney level is a specific type of clinometer.
• Inclinometer: (Noun) A general term for any device that measures angles of tilt or slope.

Synonyms

• Clinometer
• Inclinometer
• Slope gauge

Related Terms (Not Phrasal Verbs)

• Spirit level: The component within the Abney level that indicates when the instrument is horizontal.
• Sighting tube: The telescopic component used to align the instrument with the target.

Noun

1. a surveying instrument consisting of a spirit level and a sighting tube; used to measure the angle of inclination of a line from the observer to the target