SU993180A1 - Device for automatic checking of electromeasuring instrument - Google Patents

Description

The invention relates to a measurement technique and can be used in the construction of a verification system. A known installation for the automatic calibration of electrical measuring instruments, comprising a reference signal source, an optical-electrical converter unit (OEP), an OEP movement unit, a pulse shaping unit, a software program, a device for calculating an error, and a magnetic signal recording device, the first and second inputs of which connected through a device with a pulse shaping unit, and its outputs are connected to an error calculator iJIn this setup, the calibration performance is improved, but Such a disadvantage, as the complexity of the hardware implementation is exacerbated. This is due to the introduction of a magnetic signal recording device into the device, which, in addition to its complexity, also leads to a drop in the reliability of the installation. The disadvantages associated with the use of ac sources of sinusoidal signals to calibrate ac devices remain. As a prototype, a device was selected for automatic calibration of electrical measuring instruments, containing a reference source of a constant signal with an exemplary divider tia output, an OED block with an OEP displacement block and a two-channel pulse shaper, both outputs of which are connected to the control inputs of the first key, a program block connected via the input to one of the outputs of the pulse driver and the first output to the model divider, a series-connected adder and an arithmetic unit, a frequency divider m Between the first key and the OEP transfer unit, which is made discrete, and a serially connected generator of exemplary frequency, the output of which is connected to the first key, the time interval generator and the second key, the second input of which is connected to the arithmetic unit, the third output of the software program and the second time generator output intervals are connected to the corresponding inputs of the adder, and the fourth output

the program block is connected to the second input of the arithmetic block C.2

The disadvantages of this device include a large calibration time and the complexity of this process. The long time and complexity of the verification process is due to the need for additional adjustment of the level of the signal applied to the calibrated instrument and computational operations to determine the errors.

The purpose of the invention is to increase the speed of the verification process.

This goal is achieved in that a device containing serially connected reference DC voltage source, an exemplary divider, a first electronic key, terminals for connecting a rotatable device, an optoelectronic converter unit, a pulse shaper, and also a time interval shaper, a block the generator, the frequency divider, the second electronic key, the moving unit, the three outputs of which are connected to the BTopoNiy electronic key, to the model divider and to the time interval generator in, the output of which is connected to the first electronic key, and the second to the generator output and to the second input of the second electronic key, the output of which is connected to the frequency divider and then through the displacement unit to the optoelectronic converter, in the optical electronic converter unit, the converters are mixed one relative to the other is parallel to the scale of the instrument at an angle determined by twice the value of the limiting absolute error of the instrument, and a pulse counter, a logical element OR, a trigger are added to it display, the third electronic key, three inputs of which are connected respectively to the output of the pulse counter, to the output of the frequency divider and the drive of the pulse former, and the output is connected to one input of the pulse counter, and to another input - the output of the preset unit, whose input is connected to the fourth output of the software unit, and its fifth output is connected to the setup input of the display trigger, whose information input is connected to the output of the OR logic element, whose two inputs are connected to the pulse shaper.

The drawing shows a block diagram of the proposed device.

The device includes a reference voltage source 1 constant voltage, an exemplary divider 2, electronic keys 3 - 5, shaper b time intervals, software

block 7, block 8 of the OEP, block 9 of the mixing of the OEP, frequency divider 10, generator 11 of exemplary frequency, dual channel driver 12 pulses, pulse counter 13, preset block 14, logic element OR 15, display trigger 16. Position 17 denotes a test instrument.

The reference DC voltage source 1 is connected via an exemplary divider 2 to the signal input of the first electronic switch 3, the control input of which is connected to the output of the G time slot generator. A turnable device 17 is connected to the output of the electronic key 3. The control inputs of the model divider 2 and the former (5 time intervals are connected respectively to the first and second outputs of the program block 7, the signal input of the former 6 is connected to the generator of the standard frequency. The unit 8 OEP serves to convert the luminous flux reflected from the significant marks and the pointer of the instrument 17 to electrical pulses. It contains, like the prototype, two optical-electronic conversions rigidly connected However, unlike the prototype, these transducers are displaced relative to each other parallel to the scale of the device by an angle Aoi., determined by the doubled absolute error of the device being tested. And both significant marks of the scale and the pointer of the device fall into the floor of these transforms. OEP unit 8 is provided with a discrete displacement unit 9, which, through a frequency divider 10 and a second electronic cell: 4, is connected to a generator 11 of exemplary frequency. The output of the frequency divider 10 is connected via a third electronic key 5 to the first input of the pulse counter 13, which is connected via a second input to the preset block 14. The output of the counter 13 is connected to a point connecting one of the inputs of the electronic switches 5, 4. One of the other inputs of the electronic switch 4 is connected to the third output of the program block 7, and the second input of the switch 5 to the first output of the driver 12 pulses, the inputs of which are connected to the outputs of the block 8 OEP, and the outputs through the logical element OR 15 to the counting input of the trigger 16 of the display. The control input of the preset unit 14 is connected to the fourth output, and the zero input of the trigger 16 of the display is connected to the fifth output of the program block 7,

The proposed device implements, firstly, a method of calibrating electrical measuring instruments, based on the use of calibrating square-shaped signals with an adjustable duty cycle 4, and, secondly, a method of tolerantly estimating errors in verifiable marks of the scale 5, providing a significant increase in efficiency checking The principle of the device is as follows. Before starting the verification, the program unit 7 enters the program of operation of the device, which includes a set of commands for the restructuring of the model divider 2, the imaging unit 6 times and intervals, and the counter 13 pulses using the preset unit 14. An angle is established between the opto-electronic converters of the block 8. In the verification mode, the key 4 is first opened and the pulses from the generator 11 of the exemplary frequency are transmitted through the frequency divider 10 to the OEP displacement block 9. The division factor of the frequency divider 10 is selected based on the allowable movement speed of the 8 SEM block. The displacement unit 9 drives the OEP block 8. At the time of combining the first OEP (moving ahead with a calibrated mark, the first output of the pulse former 12 generates a signal that opens the electronic key 5, and from that moment the pulses from the output of the frequency divider 10 arrive at the counter 13. By the preset block 14, the counter 13 is preset to the initial state p N f, where 0 is the counter size, N is the number of pulses necessary for mixing the OEP block 8 by an angle, i.e. 4g-K, where the reciprocal of the discreteness of the output divider 10 frequencies. The value of N is determined in advance and enters with into the counter 13 through the preset block 14 from the software block 7. After the number of pulses Ы arrives at the counter 13, a signal is formed at its output by which the electronic keys 4 and 5 are closed. Moving the OEP block 8 stops, the transducers are installed symmetrically (at an angle uoi / 2) relative to the point being checked. After this, program block 7 receives commands on an exemplary divider 2 and shaper of time slots and specify their states defined by a check mark. At the output of the electronic key 3, rectangular pulses of a certain amplitude and duration are formed, corresponding to the calibrated value of the value measured by the device 17 in a check mark. . The pointer of the device 17 occupies a certain position on the scale of the device. If it falls in the DoC interval between two converters, then the device is in the class of trinity. If the pointer takes a position outside the interval Aoi. limited by the transducers, the instrument also meets the accuracy class. To automatically determine these conditions, the logical element OR 15 and the trigger 16 of the display are used. This is done as follows. At the first stage, the installation program is installed. In order to check the next mark, trigger 16 is blocked by applying a program block signal to its zero input and does not respond to pulses from the OR 15 gate. In the second stage, the inhibit signal is removed from the zero input of trigger 16 and it passes into account mode. If the pointer of the device 17 at this stage is set in the interval, then from the output of the imaging unit 12 through the logic element OR 15 only one pulse arrives at the trigger 16, and it will occupy a single state. If the pointer of the device 17 does not fall in the interval Dw1. then either no pulses will be formed at the output of the imaging unit 12 (the pointer is set to the allowable interval), or two pulses will be generated the pointer is set to the right of the allowed range). In any of these cases, trigger 16 will be in zero coning. According to the state of the trigger 16, it is possible to judge the conformity of the instrument being checked to the accuracy class in each of the calibrated scale marks. Thus, in the proposed device, the calibration time is significantly reduced. So, if in the prototype it is necessary (with the same tolerance control method) to change the parameters of the input signal of the instrument being checked twice in each calibrated mark, then one tuning is sufficient. In addition, the verification process is simplified in it, which leads to the simple operation of its hardware implementation. Thus, the exclusion of operations of additional adjustment of the parameters of the signal leads to a definite control. the shaper of the time integrals and the program block. In addition, in the proposed device, there is no need to use a residually complex arithmetic lock.

Claims (1)

Claim A device for automatic calibration of electrical measuring instruments, containing a dc reference source connected in series, a first electronic key divider, terminals for connecting the device to be verified and an optoelectronic converter unit, a pulse shaper, as well as a time interval shaper, a movement unit, a generator, a frequency divider , the second electronic key, a software unit, the three outputs of which are connected to the second electronic key, to the model divider and to the forms to a time interval adjuster, the output of which is connected to the first electronic key, and the second input to the generator output and to the second input of the second electronic key, the output of which is connected to the frequency divider and then through the displacement unit to the optoelectronic converter, which differs from I mean that, in order to improve performance, in the block of optoelectronic converters of the transforming device parallel to the scale of the device by an angle determined by the double value of the maximum absolute error of the device, and in it a pulse counter, an OR logic element, an indication trigger, a third electronic key are introduced, the three inputs of which are connected respectively to the output of the pulse counter, to the output of the frequency divider and to the output of the pulse shaper, and the output is connected to the first input of the pulse counter, to the other input of which the output is connected preset unit, the input of which is connected to the fourth output of the program unit, and its fifth output is connected to the installation input of the indication trigger, the information input of which is logically connected to the output of the OR, the two inputs of which are connected to a pulse shaper.