CN104034349A - Absolute horizontal reference precision testing system and testing method - Google Patents

Abstract

The invention relates to an absolute horizontal reference precision test system and a test method, wherein the absolute horizontal reference precision test system comprises a two-dimensional electronic level meter, a plane reflector, a leveling base and a double-shaft autocollimator; the two-dimensional electronic level meter, the plane reflector and the leveling base are sequentially arranged together from top to bottom; the biaxial autocollimator is arranged above the plane reflector and is arranged in the same optical path with the plane reflector. The invention provides a high-automation, high-efficiency and high-precision absolute horizontal reference precision testing system and a testing method.

Description

Absolute horizontal benchmark accuracy test system and test method

technical field

The invention belongs to the technical field of precision optical testing, and relates to a horizontal reference precision testing system, in particular to an absolute horizontal reference precision testing system and a testing method.

Background technique

The horizontal reference device can provide an absolute horizontal reference. It is widely used in laboratory calibration, precision metrology, geodetic survey, shooting range survey, civil engineering and other fields. Accurate absolute horizontal reference is also the prerequisite for calibration measurement and project implementation. Absolute horizontal reference accuracy is the most important technical index of the horizontal reference device, and it is the standard to measure the performance of the horizontal reference device.

Due to the natural characteristics of mercury, it is often chosen as the most important raw material for making horizontal reference devices. This horizontal reference device has the advantages of simple structure, low cost and high reliability, and is most widely used. However, usually the purity of mercury is not high, it contains more impurities, and the phenomenon of uneven density will cause errors in the absolute level reference provided by the mercury liquid level. Therefore, it is necessary to test the accuracy of the absolute horizontal reference frequently, and the test process has high requirements on test equipment, methods and personnel.

The specific steps of the traditional test method are: place the horizontal reference device to be tested on the turntable, place a plane reflector above it, fix the plane reflector so that the normal line of the plane mirror is at an angle of 45° to the horizontal, and place it on the other side of the plane reflector. Set up the autocollimating theodolite. After the mercury liquid level stabilizes for half an hour, through the reflection of the plane mirror, use the autocollimation theodolite to carry out the aiming and self-collimation measurement of the horizontal reference device to be measured. Slowly turn the turntable 180°, wait for the mercury level to stabilize again for half an hour, and then perform the aiming and autocollimating measurement with the autocollimating theodolite. According to the measured values in the two radial directions, the absolute horizontal datum accuracy is obtained through calculation.

There are many disadvantages in the traditional test method: First, the installation of the plane reflector is cumbersome, and the normal line of the mirror surface should form an angle of 45° with the horizontal. If there is any deviation in this angle, it will affect the final test accuracy. Second, slowly turn the turntable 180°, the purpose is to make the mercury liquid surface rotate to the radial direction as a whole, but in fact the mercury liquid surface cannot completely rotate 180°, resulting in The measured value in the direction is not accurate enough; third, the tester will introduce aiming error through the visual aiming of the autocollimation theodolite; fourth, the self-collimation light needs to be refracted by the plane mirror, the number of reflections is too many, and the light return effect is poor ; Fifth, during the test, the mercury level needs to be stabilized twice, and the test time is too long.

It can be seen that using the traditional method to test the absolute horizontal reference accuracy of the horizontal reference device, the installation of instruments and equipment is cumbersome, many error sources are introduced during the test process, the test accuracy is not high, and the test time is too long and the efficiency is low.

In view of the above reasons, there is a great need for an absolute horizontal reference accuracy testing system.

Contents of the invention

In order to solve the above-mentioned technical problems existing in the background technology, the present invention provides a high-automation, high-efficiency and high-precision absolute horizontal reference accuracy testing system and testing method.

The technical solution of the present invention is: the present invention provides a kind of absolute horizontal reference accuracy test system, and its special feature is: described absolute horizontal reference accuracy test system comprises two-dimensional electronic level, plane mirror, leveling base and Two-axis autocollimator; the two-dimensional electronic level, plane reflector and leveling base are set together from top to bottom; the two-axis autocollimator is arranged above the plane reflector The mirrors are placed in the same optical path.

The RMS value of the surface shape accuracy of the above-mentioned plane reflector is not lower than λ/20.

The above-mentioned plane mirror is coated with a high-reflectivity film.

The above-mentioned plane reflector is a metal plane reflector or a glass plane reflector.

The above-mentioned leveling base is a base with three or four foot screw adjustment mechanisms.

A kind of test method based on the above-mentioned absolute horizontal benchmark precision test system, its special feature is: described method comprises the following steps:

1) Install a two-dimensional electronic level, a flat mirror and a leveling base;

2) Adjust the leveling base to make the mirror surface of the plane reflector absolutely level;

3) Adjust the biaxial autocollimator to make it completely self-collimated to the plane mirror;

4) Read the test values X and Y of the orthogonal two axes of the horizontal reference device to be measured by the biaxial autocollimator, and finally according to the formula Calculate the absolute horizontal reference accuracy of the horizontal reference device to be tested.

The concrete realization mode of above-mentioned step 1) is:

1.1) Choose a stable and vibration-isolated place to place the leveling base;

1.2) Place a plane reflector above the leveling base, and the mirror normal of the plane reflector is vertically upward;

1.3) Place the two-dimensional electronic level on the plane mirror so that the granite base of the two-dimensional electronic level is in contact with the mirror surface of the plane mirror.

The specific implementation of the above step 2) is: turn on the power supply of the two-dimensional electronic level, and after the display is stable, adjust the foot screw of the leveling base, and at the same time observe the change of the absolute inclination value of the two-dimensional electronic level, and constantly adjust the level. The mirror surface of the flat mirror is absolutely flat.

The specific implementation of above-mentioned step 3) is: take away the two-dimensional electronic level, set up a biaxial autocollimator above the mirror surface of the plane mirror, and the measuring head of the biaxial autocollimator is vertically facing the plane mirror downwards The mirror surface; keep the position of the leveling base and the plane mirror stable, adjust the biaxial autocollimator to make it completely self-collimating to the plane mirror, and reset the reading to zero.

The specific implementation of above-mentioned step 4) is:

Take away the leveling base and plane mirror, keep the position of the biaxial autocollimator stable, and place the horizontal reference device to be tested in the test optical path under the measuring head of the biaxial autocollimator; Half an hour after the mercury liquid level of the horizontal reference device is stable, the test values X and Y of the two orthogonal axes are read by the biaxial autocollimator, and finally according to the formula Calculate the absolute horizontal reference accuracy of the horizontal reference device to be tested.

The advantages of the present invention are:

1. High automation. The invention adopts a two-axis autocollimator with a built-in CCD device, which completely replaces human eye aiming, realizes automatic interpretation of the autocollimation image, and outputs the test value of the autocollimation deflection angle in real time. This makes the absolute level benchmark accuracy test fundamentally realizes high automation.

2. High efficiency. The present invention adopts another erection method of the plane reflector, and realizes rapid leveling of the mirror surface of the plane reflector through the leveling base and the two-dimensional electronic level, which is faster and more convenient than the traditional erection method. At the same time, the present invention also adopts a biaxial autocollimator. Once the biaxial autocollimator is completely self-collimated to the plane mirror, the horizontal reference device to be tested can be put into the test optical path, and the biaxial autocollimator The instrument directly outputs the test value, the level reference device to be tested does not need any adjustment, the mercury liquid level only needs to be stabilized once, and the operation process of rotating the mercury liquid level by 180° and requiring a second stabilization is cancelled. This makes the absolute horizontal benchmark accuracy test fundamentally achieve high efficiency.

3. High precision. The present invention adopts another erection method of the plane reflector, realizes the precise leveling of the mirror surface of the plane reflector through the leveling base and the two-dimensional electronic level, eliminates the angle deviation of the plane reflector introduced by the traditional erection method, and The process of deflecting the self-collimated light by the plane reflector is canceled, and the light return effect is improved. At the same time, the present invention also adopts a dual-axis autocollimator, which eliminates the need for human eye alignment, eliminates alignment errors, and eliminates the need for diameter measurement, eliminating the autocollimation measurement error introduced by the incomplete rotation of the mercury liquid surface by 180° . This makes the absolute horizontal benchmark accuracy test fundamentally achieve high precision.

Description of drawings

Fig. 1 is the test schematic diagram of the absolute horizontal benchmark accuracy test system provided by the present invention;

in:

1-two-dimensional electronic level; 2-plane mirror; 3-leveling base; 4-two-axis autocollimator; 5-level reference device to be measured.

Detailed ways

The invention provides an absolute horizontal reference accuracy test system, which includes a two-dimensional electronic level, a plane reflector, a leveling base and a biaxial autocollimator; a plane reflector is placed under the biaxial autocollimator; A leveling base is placed under the plane mirror, and a two-dimensional electronic level is placed above the mirror surface; after the two-dimensional electronic level is taken away, adjust the two-axis autocollimator to completely self-collimate the plane mirror; remove the plane mirror and level Base, place the horizontal reference device to be tested under the biaxial autocollimator at the same position.

The present invention will be described in detail below in conjunction with the accompanying drawings.

Referring to Fig. 1, the present invention provides a kind of absolute level datum precision test system, the instrument equipment used in this absolute level datum precision test system comprises two-dimensional electronic level 1, plane mirror 2, leveling base 3, two-axis automatic A collimator 4 and a horizontal reference device 5 to be measured. The plane reflector in the absolute level reference accuracy testing system is placed on the leveling base, and a two-dimensional electronic level is placed above the mirror surface; after the plane reflector is leveled, the two-dimensional electronic level is The instrument is erected above the plane mirror; the measuring head of the dual-axis autocollimator is facing the mirror surface of the plane mirror; adjust the dual-axis autocollimator to completely self-align the plane mirror; remove the plane mirror and leveling base, Place the horizontal reference device to be tested in the test light path under the measuring head of the biaxial autocollimator at the same position.

The two-dimensional electronic level 1 has a display screen, which can measure the absolute inclination of the horizontal base surface, and simultaneously give out the inclination values in two orthogonal directions, and display them on the display screen in real time in the form of angles. The measurement accuracy of the two directions is 0.2″, the base is grade 0 granite base, and it is powered by dry batteries.

The diameter of the flat mirror 2 is not less than Φ200mm, the main material is glass or metal, and is coated with a high-reflectivity film, the reflectivity can reach 99%, and the RMS value of the surface shape accuracy is not lower than λ/20.

The leveling base 3 is a base with three or four foot screw adjustment mechanisms, the three foot screws are evenly distributed at 120°, the four foot screws are evenly distributed at 90°, and the load-bearing is not less than 30kg.

Dual-axis autocollimator 4 adopts CCD imaging device and visible laser light source, which can automatically collect autocollimation images, automatically interpret the autocollimation deflection angle, and at the same time give the test values of two orthogonal axes, with absolute measurement and clear There are two modes of relative measurement of zero, and the angle measurement accuracy of both axes is 0.1″.

The absolute level reference of the level reference device 5 to be measured is provided by the mercury level.

Install the test equipment according to Fig. 1, the working principle is: choose a stable and vibration-isolated place to place the leveling base 3, place the plane mirror 2 above the leveling base 3, and the mirror normal of the plane mirror 2 is vertically upward; The two-dimensional electronic level 1 is placed on the plane mirror 2, so that the granite base of the two-dimensional electronic level 1 is in contact with the mirror surface of the plane mirror 2; turn on the power of the two-dimensional electronic level 1, and adjust the leveling after the display is stable. The foot screw of the base 3, and at the same time observe the change of the absolute inclination value of the two-dimensional electronic level 1, constantly adjust the mirror surface of the plane mirror 2 to be absolutely flat; A biaxial autocollimator 4 is erected above, and the measuring head of the biaxial autocollimator 4 faces the mirror surface of the plane reflector 2 vertically downward; keep the positions of the leveling base 3 and the plane reflector 2 stable, Adjust the biaxial autocollimator 4 to make it completely self-collimated to the plane mirror 2, and clear the reading; remove the leveling base 3 and the plane mirror 2, and keep the position of the biaxial autocollimator 4 stable Unchanged, the horizontal reference device 5 to be tested is placed in the test optical path below the measuring head of the biaxial autocollimator 4; after the mercury liquid level of the horizontal reference device 5 to be measured is stable for half an hour, the two-axis autocollimator Instrument 4 reads the test values X and Y of the orthogonal two axes, and finally according to the formula Calculate the absolute horizontal reference accuracy of the horizontal reference device 5 to be measured.

Claims (10)

1. an abswolute level reference precision test macro, is characterized in that: described abswolute level reference precision test macro comprises Two-dimensional electron level meter, plane mirror, leveling pedestal and twin shaft autocollimator; Described Two-dimensional electron level meter, plane mirror and leveling pedestal set gradually together from top to bottom; Described twin shaft autocollimator is arranged on the top of plane mirror and is placed in same light path with plane mirror.

2. abswolute level reference precision test macro according to claim 1, is characterized in that: the surface figure accuracy RMS value of described plane mirror is not less than λ/20.

3. abswolute level reference precision test macro according to claim 2, is characterized in that: described plane mirror is coated with high reflection film.

4. abswolute level reference precision test macro according to claim 3, is characterized in that: described plane mirror is metal flat reflector or glass planar catoptron.

5. abswolute level reference precision test macro according to claim 4, is characterized in that: described leveling pedestal is the pedestal with three or four foot screw governor motions.

6. the method for testing based on abswolute level reference precision test macro as claimed in claim 5, is characterized in that: said method comprising the steps of:

1) Two-dimensional electron level meter, plane mirror and leveling pedestal are installed;

2) regulate leveling pedestal that the minute surface of plane mirror is definitely flattened;

3) regulate twin shaft autocollimator to make it to the complete autocollimatic of plane mirror;

4) by twin shaft autocollimator, read axial test value X and the Y of quadrature two of level reference apparatus to be measured, finally according to formula calculate the abswolute level reference precision of level reference apparatus to be measured.

7. method of testing according to claim 6, is characterized in that: specific implementation described step 1) is:

1.1) select the place of steady vibration isolation to settle leveling pedestal;

1.2) above leveling pedestal, lay plane mirror, the minute surface normal of plane mirror straight up;

1.3) Two-dimensional electron level meter is placed on plane mirror, the grouan base of Two-dimensional electron level meter is contacted with the minute surface of plane mirror.

8. method of testing according to claim 7, it is characterized in that: specific implementation described step 2) is: the power supply of opening Two-dimensional electron level meter, after registration is stable, regulate the foot screw of leveling pedestal, and observe the absolute inclination magnitude variations of Two-dimensional electron level meter simultaneously, constantly regulate the minute surface of plane mirror is definitely flattened.

9. method of testing according to claim 8, it is characterized in that: specific implementation described step 3) is: take Two-dimensional electron level meter away, above the minute surface of plane mirror, set up twin shaft autocollimator, the measuring head of twin shaft autocollimator is straight down over against the minute surface of plane mirror; Keep the position stability of leveling pedestal and plane mirror constant, regulate twin shaft autocollimator to make it to the complete autocollimatic of plane mirror, and by registration zero clearing.

10. method of testing according to claim 9, is characterized in that: specific implementation described step 4) is:

Take leveling pedestal and plane mirror away, keep the position stability of twin shaft autocollimator constant, level reference apparatus to be measured is placed in the optical system for testing of measuring head below of twin shaft autocollimator; Until the mercury liquid level stabilizing of level reference apparatus to be measured, after half an hour, by twin shaft autocollimator, read quadrature two axial test value X and Y, finally according to formula calculate the abswolute level reference precision of level reference apparatus to be measured.