The working principle of different types of spirit level tool (1)

Micro tilt level(spirit level tool)
(spirit level tool)A common level used to obtain horizontal line of sight by means of micro tilt screw. During operation, the instrument shall be roughly leveled with a circular level. Before each reading, the compliance level shall be tilted in the vertical plane with the help of a micro tilt screw until the compliance level bubble is accurately centered to make the line of sight level. Compared with ordinary level, the former tube level has small division value, high sensitivity, large magnification of telescope, strong brightness and solid instrument structure. In particular, the connection between telescope and tube level is firm. It is equipped with optical micrometer and precision level ruler to improve the reading accuracy. The telescope magnification of the micro tilt precision level produced in China is 40 times, the division value of the tube level is 10 ″ / 2mm, and the minimum reading of the optical micrometer is 0.05mm. The aiming part of the telescope, the tube level and the optical micrometer are installed in the heat shield.

Automatic Anping(spirit level tool)
A spirit level tool that obtains a horizontal line of sight by means of an automatic leveling compensator. Its main feature is that when the line of sight of the telescope tilts slightly, the compensator moves the telescope relatively under the action of gravity, so that the ruler reading at the line of sight level can be obtained automatically and quickly. The basic principle of compensation is: when the line of sight of the telescope is horizontal, the image point Z0 composed of object point P on the leveling rod at the same height as the main point of the objective lens shall fall on the crosshair intersection Z. When the telescope tilts a small angle to the horizontal line α After that, the crosshair intersection Z moves upward, but the image point Z0 is still in place, resulting in a reading difference z0z. When it is very small, it can be considered that the spacing of z0z is α× F '(f' is the focal length of the objective lens), at this time, a compensator can be installed at point K in the optical path to produce a bending angle of the light β， In satisfaction α× f′= β× Under the condition of S0 (S0 is the distance from the compensator to the center of the cross wire, i.e. KZ), the image Z0 falls on the Z point; Or make the crosshair automatically swing in the opposite direction to the instrument, and the crosshair intersection Z falls on point Z0.

If the light path adopts translation instead of light bending, as long as the translation amount is equal to z0z, the crosshair intersection Z falls on the image point Z0, which can also achieve the coincidence of Z0 and Z. According to the structure, the automatic leveling compensator can be divided into movable objective lens, movable crosshair and hanging prism. The compensation device has a "pendulum". When the line of sight of the telescope tilts slightly, the compensation element will swing. In order to stabilize the swing of the "pendulum" as soon as possible, an air damper or magnetic damper must be installed. Compared with the micro tilt level, this instrument has high efficiency and stable precision, especially in areas with windy and large temperature changes.