RU197046U1 - DEVICE FOR TESTING AND CALIBRATING LEVEL MEASUREMENT DEVICES - Google Patents

Abstract

The utility model relates to instrumentation, in particular to devices for testing and calibrating equipment for measuring liquid level, specifying the distance for reproducing a unit of length (level) during calibration and calibration of level measuring instruments by comparing readings between a standard means of measuring length (level) and a verifiable or calibrated means of level measurement. The task is to simplify the design while reducing the error of calibration and calibration. A device for checking and calibrating level measuring instruments in It includes the fixed part 1, the moving part 2 and the linear part 3. The fixed part 1 is made of two blocks 4 and 5. The movable part 6 is made in the form of a base with adjustable supports, on which the reflector 7 is mounted with the possibility of movement along the linear part 3. At the same time block 4 of the fixed part 1 is located in front of the reflector 7 in front of it and is made in the form of a vertically mounted metal frame 8 with an instrument compartment 9 for placing control devices (not shown in the drawing) and a fixed base 10. On a fixed base 10 the actuator 11, the reference level gauge 12 and the calibrated level gauge 13 are rigidly fixed. The second block 5 of the fixed part 1 is mounted behind the reflector 7. The linear part 3 is made in the form of linear guides 14, which are metal profiles (rails) for moving the movable part 6 along them, and connected on one side with the base 10 of the fixed part 1. The movable part 6 moves along the linear part 3 on the rollers placed in the supports 15. In this case, the movable part 6 is connected to the electric drive 11 using a metal cable 16. Reflector 7 rigidly connected with the movable base 6. The distance meter from the movable part 6 to the fixed part 4 is a reference level gauge 12 in the form of a laser range finder or laser interferometer, also mounted on the fixed part 1 - the base 10. The second block 5 of the fixed part 1, located behind the reflector 7 is made in the form of a vertically mounted fixed element and is rigidly connected with the second side of the linear part 3. The reference laser rangefinder 12 'is rigidly fixed to the fixed base 10, has a measuring range th up to 40 m and is used to measure distances with an accuracy of ± 1 mm. When using a 12 '' laser interferometer rigidly fixed on the base 10 as a reference level gauge, a laser range finder 17 with a measurement range is not additionally introduced into the device to determine the reference point of its measurements more than 0.2 m, which is also mounted on a fixed base 10. The laser range finder 17 and the laser interferometer 12 '' are used to measure distances with an accuracy of ± 0.3 mm. When checking and calibrating waveguide level gauges on the second th block 5 fixed part 1, installed for the reflector 7 and made in a fixed vertical element can be placed coil 18 to a tension level measuring means waveguides and a stopper 19 for fixing force of tension. 3 s.p. f-ly, 1 ill.

Description

The utility model relates to instrumentation, in particular to devices for testing and calibrating equipment for measuring liquid level, setting the distance for reproducing a unit of length (level) during calibration and calibration of level measuring instruments by comparing readings between the standard measuring instrument for length (level) and the calibrated or a calibrated level meter.

A known device for checking and calibrating level measuring instruments “Stand for checking level gauges”, described in the patent for utility model No. 140028, manufactured by LLC ElMetro-Engineering, Russia (see Appendix).

The well-known device (Figure 1) contains: a linear part 1 with a fixed base rigidly fixed on it 2, providing connection of the level gauges to be verified, and a movable part 3 with a base 4 rigidly fixed on it. The linear part 1 is presented in the form of metal profiles fixed on supports. On a fixed base 2 of the linear part 1, a calibrated level gauge 5 is firmly fixed; a reflector 6 is fixed on the base 4 of the movable part 3, and the level gauge 5 to be verified is mounted so that its horizontal axis is perpendicular to the plane of the reflector 6. The movable part 3 is designed to move the reflector 6 in the horizontal plane along the linear part 1 and is equipped with its fixation elements in a stationary state at given points. There is a distance meter from the moving part to the fixed one, presented in the form of a magnetic tape 7, which is laid on the linear part 1 of the stand, and the device 8 is a linear displacement transducer mounted on the moving part 3, designed to read the magnetic tape and representing a linear encoder. The stand is equipped with temperature sensors 9 and, if necessary, an air circulation system 10. In the fixed base 2 of the linear part of the stand, longitudinal grooves 11 can be made for mounting various level gauges 5 (not shown in the drawing). There is also a position sensor 12. In the movable part 3 of the stand, the reflector 6 is attached to the base 4 by means of a spherical hinge 13.

A disadvantage of the known device is that the magnetic tape 7 is laid on the linear part 1, which leads to the fact that the deviation from the straightness of the linear part is transmitted to the magnetic tape, thereby the magnetic tape requires alignment during use. Another drawback of the magnetic tape is that the stand must have temperature sensors 9 and an air circulation system 10 to take into account and reduce the linear temperature expansion that affects the readings of the distance meter. Another disadvantage of the known device is the presence of a spherical hinge 13, which leads to a decrease in the rigidity of the system compared to a rigid bolt fastening.

The closest in technical essence to the claimed one is a stand for verification and calibration of level measuring instruments "Metrological stand for verification, calibration of level meters and level alarms" described in patent for invention 2 690 701 manufactured by Teknou JSC, Russia (see Appendix) and selected as a prototype.

The known device comprises: a linear part with elements for connecting verifiable level switches and a moving part, a reflector and means for moving the reflector in a horizontal plane along the stationary linear part of the stand, a cabinet with a metal shield is rigidly fixed on the linear part for connecting a level indicator or level gauge, movable parts, the movement of which is carried out by means of a precision stepper drive using a reinforced toothed polyurethane belt, on which a reflector is repaired, to measure the distance from a fixed metal shield to a movable reflector, the stand contains a high-precision laser interferometer or laser range finder, a measuring unit is introduced into the stand to control temperature, humidity and ambient pressure. To use the laser interferometer, a reference sensor is installed on the precision guide rails of the linear part to determine the reference point. To carry out measurements using a laser interferometer, a linear retroreflector is mounted on the moving part of the carrier frame. The laser interferometer or laser range finder is located behind the reflector and is rigidly fixed to the floor by means of a pedestal that is not connected with the main frame of the stand. To work with contact cable (capacitive) level gauges, the stand contains a tension system, including an electric winch with a tension sensor mounted on a pedestal.

The disadvantage of the prototype is the complexity of the design, due to the following structural elements:

the presence of a reference sensor for determining the reference point;

the need to fasten the laser interferometer through an optically adjustable platform to the floor by means of a separate stand that is not connected with the main frame of the stand;

installing a reference laser interferometer or laser range finder behind a reflective surface;

the execution of the fixed part in the form of a continuous metal shield;

the presence of precision trolleys and a precision stepper drive with a reinforced toothed belt for moving the moving part along the guides.

In this case, the installation of the reference sensor leads to the fact that the measurement system is not connected with a fixed base, which entails the appearance of an additional error. The laser interferometer or laser range finder in the prototype is rigidly fixed to the floor behind the reflector, is not connected with the linear part of the stand, which also leads to an additional error in the positioning of the system in stationary conditions of unrelated elements. In addition, the placement of the reference laser interferometer and the laser range finder behind the reflective surface leads to the need to recalculate the readings of the reference devices, which also leads to the appearance of an additional systematic measurement error.

The objective is to simplify the design while reducing the error of verification and calibration.

The problem is solved in that in a device for checking and calibrating level measuring instruments, including a fixed part with an instrument compartment, made of two blocks, one of which is located in front of the reflector and on which the calibrated level gauge is mounted, and the second block of the fixed part is installed behind the reflector, an electric drive for moving the movable part, made in the form of a base with adjustable supports, on which a reflector mounted opposite the calibrated level gauge is mounted with the possibility of movement the linear part in the form of linear guides made directly from the side with the fixed part, made of metal profiles to move the moving part along them, the distance meter from the moving part to the fixed part, which is a reference level gauge, also mounted on the fixed part, according to the utility model the fixed part, located in front of the reflector, is made in the form of a vertically mounted metal frame with an instrument compartment and with a calibrated level gauge attached to it, and base on which are rigidly fixed drive, a reference transmitter, and the second block of the fixed part located behind the reflector, is rigidly connected with the second side of the linear part and formed in a fixed vertical member, wherein the actuator is coupled to the movable portion via the cable.

In this case, a laser range finder can be used as a reference level meter.

Also, a laser interferometer can be used as a reference level meter, and then a laser interferometer reference point element can be introduced into the device, which is a laser range finder with a measurement range of up to 0.2 m, rigidly fixed to the fixed base of the first block of the fixed part.

In addition, during the verification and calibration of waveguide level gauges on the second block of the fixed part, installed behind the reflector and made in the form of a vertically stationary element, a coil for tensioning the waveguides of level measuring instruments and a stopper can be placed to fix their tension.

The execution of the fixed part of the device from the first block placed in front of the reflector, made in the form of a metal frame with a calibrated device rigidly fixed on it, and a fixed base on which the electric drive and the reference level gauge are rigidly fixed in conjunction with hard fixing of the second block of the fixed part with the second side linear parts, makes it possible with a simpler design to avoid additional error due to unstable positioning of the elements of the measuring system.

The technical result is a simplification of the design while increasing the accuracy of verification and calibration.

The inventive device has a novelty in comparison with the prototype, differing from it by such significant features as the execution of the block of the fixed part, placed in front of the reflector, in the form of a vertically mounted metal frame with an instrument compartment and a verified level gauge attached to it, and a fixed base, rigid mounting on this basis an electric drive, a reference level gauge, the implementation of the second block of the fixed part located behind the reflector, rigidly connected with the second side of the linear part and its implementation in the form of a stationary vertical element on which a coil is placed for tensioning the waveguides of the level measuring instruments and a stopper for fixing the efforts of their tension, connecting the electric drive to the moving part using a cable, ensuring the achievement of a given result.

The inventive device can be used for metrological purposes for verification or calibration of level measuring instruments, and therefore meets the criterion of "industrial applicability".

The utility model is illustrated in the drawing, which shows a diagram of the device.

A device for checking and calibrating level measuring instruments includes a fixed part 1, a movable part 2 and a linear part 3. The fixed part 1 is made of two blocks 4 and 5. The movable part 2 includes a base 6 with adjustable supports, on which it is mounted with the possibility of movement the reflector 7 along the linear part 3. In this case, the block 4 of the fixed part 1 is located in front of the reflector 7 opposite it and is made in the form of a vertically mounted metal frame 8 with an instrument compartment 9 for accommodating control devices (not shown in the drawing rendered) and the fixed base 10. On the fixed base 10, the electric actuator 11, the reference level gauge 12 and the calibrated level gauge 13 are rigidly fixed. The second block 5 of the fixed part 1 is installed behind the reflector 7. The linear part 3 is made in the form of linear guides 14, which are metal profiles ( rails) for moving the movable base 6 along them, and is connected on one side with the base 10 of the fixed part 1. The movable part 2 moves along the linear part 3 on the rollers placed in the supports 15. In this case, the movable part 2 is connected on with an electric drive 11 using a metal cable 16. The reflector 7 is rigidly connected with the movable base 6.

The distance meter from the moving part 2 to the fixed part 4 is a reference level gauge 12 in the form of a laser rangefinder or a laser interferometer, also mounted on the fixed part 1 - the base 10. The second block 5 of the fixed part 1, placed behind the reflector 7, is made in the form of a vertically mounted fixed element 5 'and is rigidly connected with the second side of the linear part 3.

The reference laser rangefinder 12 'is rigidly mounted on a fixed base 10, has a measurement range of up to 40 m and is used to measure distances with an accuracy of ± 1 mm.

When using a 12 '' laser interferometer rigidly mounted on the base 10 as a reference level gauge, a laser range finder 17 with a measurement range of not more than 0.2 m, which is also mounted on a fixed base 10, is additionally introduced into the device to determine the reference point of its measurements. rangefinder 17 and laser interferometer 12 '' are used for distance measurements with an accuracy of ± 0.3 mm.

When checking and calibrating the waveguide level gauges on the second block 5 of the fixed part 1, installed behind the reflector 7 and made in the form of a stationary vertical element 5 ', a coil 18 for tensioning the waveguides of the level measuring instruments and a stopper 19 for fixing the tension force can be placed.

A device for checking and calibrating level measuring instruments works as follows.

On a fixed base 10 of the fixed part 1 is fixed calibrated or calibrated means 13 level measurement. Moving the movable part 2 along the linear part 3 is performed using an electric drive 11 and a metal cable 16. The reflector 7 simulates the position of the level, the distance from the reflecting surface 7 is measured by a laser range finder 12 '. For high-precision measurements of the position of the reflecting surface, a laser range finder 17 and a laser interferometer 12 ″ with a reflecting element 20 are used. Moving the movable part 2 can occur in manual and automatic mode. For the manual movement of the movable part 2, it is necessary to disconnect the cable 16 from the movable part 2. To verify the level measuring means 13 with flexible waveguides, the waveguides are pulled using a coil 18 and a stopper 19 located behind the reflector 7 on the fixed block 5 of the fixed part 1. The readings are compared by direct comparison length measuring instruments 12 ', or 12' 'and 17 with indications of the level measuring means to be verified 13.

Compared with the prototype, the inventive device for checking level measuring instruments is simpler in design and quite accurate due to the rigid connection of the fixed part 1, linear part 3, movable part 2, as well as the installation of measuring instruments for length 12 'or 12' 'and 17 on the fixed part 1 in front of the reflector 7.

Claims (4)

1. Device for checking and calibrating level measuring instruments, including a fixed part with an instrument compartment, made of two blocks, one of which is located in front of the reflector and on which the calibrated level gauge is mounted, and the second block of the fixed part is installed behind the reflector, an electric drive for moving the moving part made in the form of a base with adjustable supports, on which a reflector is mounted with the ability to move, mounted opposite the calibrated level gauge, rigidly connected on one side with the other part is a linear part in the form of linear guides made of metal profiles for moving the moving part along them, a distance meter from the moving part to the fixed one, which is a reference level gauge also mounted on the fixed part, characterized in that the block of the fixed part is placed in front of the reflector , made in the form of a vertically mounted metal frame with an instrument compartment and with a verifiable level gauge fixed to it, and a fixed base on which e an electric drive, a reference level gauge, and a second block of the fixed part located behind the reflector, is rigidly connected to the second side of the linear part and is made in the form of a stationary vertical element, while the electric drive is connected to the movable part by a cable. 2. The device according to claim 1, characterized in that a laser range finder is used as a reference level gauge therein. 3. The device according to claim 1, characterized in that a laser interferometer is used as a reference level gauge therein, while an element for determining the reference point of the laser interferometer, which is a laser range finder with a measurement range of up to 0.2 m, is rigidly inserted on the fixed base of the first block of the fixed part. 4. The device according to claim 1, characterized in that during calibration and calibration of the waveguide level gauges, a coil for tensioning the waveguides of the level measuring devices and a stopper for fixing the tensioning force are placed in it on the stationary vertical element of the second side of the fixed part.

Images