RU-2861605-C1 - METHOD FOR TRANSFERRING PLANE ANGLE UNIT TO LEVELS AT THEIR OPERATION SITES

RU2861605C1RU 2861605 C1RU2861605 C1RU 2861605C1RU-2861605-C1

Abstract

FIELD: geodesy. SUBSTANCE: invention relates to methods for verifying geodetic instruments. The essence of the method is that the angle between the sighting axis of the telescope of the level being verified and the horizontal plane is determined in accordance with the level verification procedure by sequentially measuring the displacement of the middle thread of the level reticle relative to the centre of the autocollimator scale, additionally, the sighting axis of the autocollimator is aimed at a mirror plumb reflecting surface, which, under the action of the gravity of a weight, forms a plane perpendicular to the horizontal plane; a line connecting the sighting axis of the autocollimator with the normal to the reflecting surface is obtained and the autocollimator readings are taken; the angle of inclination of the sighting axis of the level being verified is determined as the difference between the autocollimator readings obtained when aiming at the plumb reflecting surface and aiming at the image of the reticle of the telescope of the level being verified. EFFECT: increasing the accuracy of transferring the plane angle unit to levels. 1 cl, 1 dwg

Inventors

Konyukhov Mikhail Anatolevich
KLEJMENOV YURIJ ANATOLEVICH

Dates

Publication Date: 20260506
Application Date: 20250729

Claims (1)

A method for testing a level whereby the angle between the sighting axis of the telescope of the tested level and the horizon plane is determined in accordance with the level testing procedure by successive measurements of the displacement of the middle thread of the level reticle relative to the center of the autocollimator scale, characterized in that the sighting axis of the autocollimator is additionally aimed at a mirror-like vertical reflecting surface that forms, under the action of the gravity of the load, a plane perpendicular to the horizon plane; in this case, a line is obtained connecting the sighting axis of the autocollimator with the normal to the vertical reflecting surface and readings are taken from the autocollimator; in this case, the reticle of the telescope of the tested level is brought to the horizon plane using a built-in cylindrical level or compensator; the angle of inclination of the sighting axis of the tested level is determined as the difference between the autocollimator readings obtained when aiming at the vertical reflecting surface and when aiming at the image of the reticle of the telescope of the tested level.

Description

The proposed invention relates to the field of ensuring the uniformity of plane angle measurements and can be used to determine the metrological characteristics of levels during their verification at the places of operation, by the method of direct comparison with a digital autocollimator (a working standard of a plane angle) by determining the angle between the sighting axis of the telescope and the plane of the horizon. A method is known for transferring a unit of plane angle to levels, which consists in the fact that the angle between the sighting axis of the telescope of the level being tested and the plane of the horizon is determined by comparing the position of the image of the reticle of the telescope of the level being tested, formed in the field of view of a horizontal collimator with a built-in compensator, with the vertical scale of the reticle of the horizontal collimator of the collimator stand [1]. The disadvantages of this method are: the vertical scale of the reticle of the horizontal collimator does not ensure the measurement of the actual value of the angle between the sighting axis of the telescope of the level being tested and the horizon plane in accordance with the verification procedure [2], due to the fact that the angular distance between the lines of the vertical scale ensures the determination of the location of the image of the reticle of the telescope of the level being tested within the tolerance field of ±15'', and as a consequence, it is impossible to determine the value of the deviation of the reticle of the level being tested relative to the plane of the horizon, which is the horizontal reticle of the horizontal collimator installed in the plane of the horizon using an optical-mechanical compensator, and, consequently, it is impossible to calculate the standard deviation of the measurements of the elevations by the level being tested; the optical-mechanical compensator, with the help of which the collimator's sighting axis is set in the horizontal plane, has an optical scheme and design similar to the levels being tested, which in itself is an unstable system with an angle of deviation of the sighting axis from the horizontal plane; the limitations of its application in places where the levels being tested are used, since the device for its implementation is installed permanently on a concrete base in laboratory conditions. The closest in essence to the proposed invention is a method for transmitting a unit of plane angle to levels [2], and a device for implementing it [3], which consists in the fact that the angle of inclination of the sighting axis of the telescope of the tested level is measured by an autocollimator, the sighting axis of which is set parallel to the plane of the horizon with the help of an optical block with a pentaprism and a cuvette with liquid, the reflecting surface of which is used as a horizon standard. The total error of the known method can be represented in the following form [4]: where Δ AK is the error of the autocollimator, Δ PP is the error of the working angle of the pentaprism, Δ OP is the error caused by vibrations of the reflecting surface of the liquid from the horizon due to various disturbing factors (vibrations of the base, movement of air currents, etc.). Disadvantages of the known method include: to eliminate surface vibrations of the liquid, which are a source of additional error, special foundations are created in laboratory conditions on which the autocollimator and the verified level are mounted. The creation of such special foundations is economically impractical and practically impossible to implement in the locations where the levels are used, which limits the application of the known method in these conditions; the pentaprism used in the prototype method is the main source of additional error (Δ PP ), which contributes up to 63% (0.26") to the total error in transmitting a unit of plane angle. This leads to a decrease in the accuracy of transmission of the unit of plane angle and limited functionality of the known method. The objectives of the proposed invention are to increase the accuracy of transferring the unit of plane angle to levels, as well as to expand the scope of its application by removing the restriction on the use of the method in laboratory conditions [2], which will make it possible to transfer the unit of plane angle to verified levels in the places of their operation. The stated objective is achieved by the fact that the angle between the sighting axis of the telescope of the level being tested and the horizon plane is determined in accordance with the method of its testing by successive multiple measurements of the displacement of the middle thread of the level's reticle relative to the center of the autocollimator scale, characterized in that, in order to set the sighting axis of the autocollimator parallel to the horizon plane, a vertical reflecting surface is used, which, under the action of the gravi