GN 2277

Bull´s eye levels

with mounting flange

GN 2277

Bull´s eye levels
Bull´s eye levels

GN 2277

Bull´s eye levels
Bull´s eye levels


Type 30: Angle minutes, bubble move by 2mm


  • Type A: Mounting flange, for bolting surface
  • Type B: Mounting flange, for inserting (collar)



anodized, natural colour ALN

anodized, black ALS

Spirit level element

Glass plastic body


coulourless-transparent K

Casting compound


Bull´s eye levels GN 2277 are used to check the horizontal position of jigs, machines, devices, appliances and instruments.

The spirit levels are aligned in relation to the reference surface so that the bubble is located inside the marking ring when the horizontal position of the contact surface is achieved.

  • Filling, green-transparent
  • Other sensitivities
  • Housing in brass or Stainless Steel

Definition of terms

A spirit level is hollow body filled with a fluid and a gas bubble which is used to check the horizontal position of an object. The position of the gas bubble in the fluid shows the angle and the direction at which the object is inclined in relation to the horizontal level.

The function

The hollow body containing the fluid and the gas bubble has a defined radius at its topic side, causing the gas bubble to float by its buoyancy always to the highest point.

The transparent upper section normally carries markings or a circle centric to the biddle position. If the gas bubble is centered precisely inside the merking and if the air level is properly adjusted, the object to be checked is in the horizontal position.


Types of spirit levels

Spirit levels are available as bull´s eye levels or screw-on levels.

Bull´s eye levels simultaneously measure the angle of inclination and the angular position, e.g. of a certain level, whereas screw-on levels indicate the angle of inclination in one dimension only along the axis of the level.


The sensitivity of spirit levels is given as angle of inclination, e.g. 30 angular minutes or 0.5 degrees. This is the angle of inclination by which the spirit level must be tilted to make the bubble move by 2 mm. A spirit level with a sensitivity of 6 angular minutes therefore has a higher sensitivity than a spirit level with a sensitivity of 30 angular minutes.


Angle of inclination and difference in altitude

Sensitivity is sometimes also given in millimetre per metre, i.e. as difference in altitude per unit of the length. See also the reference table opposite.

Difference in altitudeAngle w-
in milimetre per metrein angular minutesDegree, decimal

Installation example

Bull´s eye levels and levelling elements - in this example, levelling elements  GN 355 

and assmebly tool GN 355.1 - are ideal to use when a holding plate is to be brought into an exact horizontal position.

Even after the initial adjustment, the bull´s eye level remains in the unit so that the correct allignment can be checked and adjusted again.



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