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Digital inclinometer

An inclinometer (also inclinometer , gradient knife , Clinometer , Gefällsmesser , altimeter , inclinometer or clinometer ( English clinometer )) is a measuring instrument for measuring the slope or angle measurement in civil engineering , in the aerospace , shipping , military entity (Artillery) and also partially in Transportation. The heights of trees, structures, masts etc. can also be determined indirectly (calculation of the height from the measuring distance and vertical angle with the help of angle functions ).

The angle scale is usually divided into degrees and percent ( slope ), with more sophisticated devices also in further degrees (e.g. gon or mil ). If a ruler can be connected, the measuring table is in miniature .


Dragonfly inclinometer from the Eugene Dietzgen Company, Chicago

The simplest design consists of a pointer pointing downwards (vertical) under its own weight, which indicates the angle on a scale. To prevent vibrations, it may have damping. The horizontal is determined by a reference side of the measuring instrument. The accuracy of the slope meters is about a tenth of a degree in the top devices (e.g. from Meridian), and about 0.5 ° in the simpler ones.

In addition, an electrical inclinometer can be implemented in which a resistance track is mounted in a vessel that is filled with a conductive liquid such as mercury . If the container is inclined, the resistance track is immersed in the conductive liquid to different degrees.

Digital inclinometers work with the help of acceleration sensors , which measure the acceleration in the earth's gravity field, an electronic circuit for processing the measurement signal and a digital display. [Receipt?]

Mechanical devices with pendulum bodies

Slope knife

There is a fairly manageable number of manufacturers and types worldwide. These often look different and have either a rod-shaped or a circular pendulum body.

In another design, the inclinometer itself forms the pendulum body. It is a round profile with an imbalance so that the inclinometer rolls on an inclined plane and assumes a position of equilibrium depending on the slope. The special feature of this type is that it does not have any moving parts.

Mechanical devices without pendulum bodies

  • Dragonfly inclinometer with integrated telescope (various manufacturers, e.g. R. & A. Rost, Vienna ): The object to be measured is sighted through a telescope. A dragonfly is faded in via a mirror . You adjust the level until the air bubble is in the middle and read the value on a scale.
  • Dragonfly inclinometer without telescope: The principle is similar, you adjust a scale so that the air bubble in the dragonfly is in the middle and read off the value.
  • Theodolites

Electronic equipment

Digital inclinometer
  • Digital measuring devices. Digital inclinometers are often integrated in spirit levels.
  • Inclinometers integrated in digital laser range finders.
  • For staking out in construction, channel lasers are used in which an electronic inclinometer is combined with a laser .
  • Digital theodolites and total stations

Use of inclinometers in shipping

Rolling around the longitudinal axis (x)
Pounding around the transverse axis (y)

The inclination of a ship ( " heel "), by movements of the rudder are affected and sailing ships in addition by the Anholen and easing of sailing. Ships are tilted by cross wind. The more constant a ship's angle of inclination, the less energy it loses from rolling. The heavier and wider a ship, the longer its roll period (its reciprocal value is the roll frequency).

The more precisely the helmsman knows the amount of heel and the roll period, the more constant he can - through steering movements - keep the inclination of the ship. At a constant incline, the ship's fuel consumption is minimal; rolling costs energy. Ships can maximize their speed by minimizing taxiing. There are electronic inclinometers that calculate the rolling period to the second and display it continuously. The computer control system also regularly creates a trend diagram for heel and roll amplitude and gives an alarm if the ship tips over to one side.

Some ships have fin stabilizers . To control them, information on the angle of inclination or roll period is required.

Web links

Commons : inclinometer  - collection of images, videos, and audio files


  1. Yaw and pitch also cost energy; the longer a ship is, the less it yaws and pounds.
  2. VDR (Ed.): Deutsche Seeschifffahrt , September 2014, p. 24 ( online ; pdf, 9 MB)