Modern optical theodolites are usually equipped with optical plumb bobs located on the alidade part or on the stand, which are used to center the theodolite over the top of the measured horizontal angle. ...

Autoreduction compensators last 10-15 years are used in many surveying and geodetic devices of new designs. They significantly improve the technology of surveying and measuring works, increase labor productivity and accuracy. ...

Visual axis of levels, common in practice, is set horizontally with a cylindrical level by bringing its bubble in the middle position. Setting the bubble in the zero point takes a lot of time, especially with a high sensitivity of the level, when leveling on unstable soils and in underground workings.