SU1714547A1 - Electrical measuring instrument tester - Google Patents

Abstract

The invention relates to a measuring technique and can be used in the construction of automatic calibration systems. The purpose of the invention is to increase the reliability and accuracy of verification based on the dynamic properties of the instrument being checked. The installation contains a block 1 of opto-electronic converters, a block 4 of formation of pulses, a software block 7, a block 8 of displacement of opto-electronic converters, a source 9 of a reference signal, an exemplary 10 and an additional 11 dividers, a generator 13 of linearly varying voltage, an adder 12 signals, a comparator 14, two keys 15 and 16, an inverter 17 and a block 18 for indicating the results of verification. The installation ensures that the results of verification are independent of the dynamic properties of the device 19 being tested by applying linear-shaped signals to its input, the rate of change of which is chosen so that the calibration verification errors are commensurate with the random measurement errors of the device. In addition, the setup allows one to obtain quantitative characteristics of the results of verification, on the basis of which it is possible to analyze the distribution of measurement errors on the instrument scale. 3 il. (Ls

Description

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The invention relates to measuring instruments and can be used in the construction of calibration systems.

The purpose of the invention is to increase the reliability and accuracy of verification based on the dynamic properties of the instrument being checked.

Figure 1 shows the functional diagram of the installation; figure 2 - graphs, explaining the principle of operation of the installation; FIG. 3 is a block diagram of the operation of the program block.

The installation contains a block 1 of opto-electronic converters, including two opto-electronic converters 2 and 3, a block 4 of formation of pulses containing drivers 5 and 6 pulses, a program block 7, a block 8 of displacement of opto-electronic converters, a source 9 of a reference signal, an exemplary divider 10, an additional divider 11, a signal adder 12, a linearly varying voltage generator 13 (CLAY), a comparator 14, keys 15 and 16, an inverter 17, a calibration result indication block 18, and a testable device 19.

The marks on the scale of the device 19 and its pointer pointer are optically connected to the first 2 and second 3 opto-electronic converters of unit 1, respectively, whose outputs are connected to the inputs of drivers 5 and 6 of the pulses of block 4, respectively; the output of the driver 6 of the pulses unit 7, the second input of which is connected to the output of the pulse generator 5, the control input of the first key 15 and through the inverter 17c the input of the second key 16, the control input of which is connected to the output of the comparator 14, the first input to The additional divider 11 is costly connected to the output of the source 9 of the reference signal, as well as through the exemplary divider 10 to the first input of the adder 12, the output of which is connected to the terminals of the testable device, and the second input to the output of the generator 13 of linearly varying voltage the second input of the comparator 14 and the input of the key 15, the output of which is connected to the input of the calibration results indication block 18, the program block 7 by the first output connected to the input of the generator 13, to the control input of the exemplary divider 10 and the input of the block 8 opto-electronic transducers, the output of which is mechanically connected with the unit 1, the key output 16 connected to the indicator No standards.

The installation works as follows.

Before starting the verification, the program unit 7 is entered into the program block, which includes successive commands for switching the model divider

5 10. Commands; arriving at the model divider 10, successively set its states corresponding to each significant mark of the instrument 19 being turned, minus the absolute value of the allowable

10 errors A At the output of the additional divider 11, a signal is generated, the value of which is constant and equal to twice the permissible error of the device being checked.

15 The installation starts at the command of the operator and occurs in the following sequence. On command from program block 7 in accordance with the selected program, the signal from the output of the model

The 0 divider 10 is fed to the first input of the adder 12, the output of which is connected to the input terminals of the device being turned. At the same time, the movement unit 8 drives the optical-electronic unit 1.

5 transducers and moves it until the light beam of the transducer 3 hits the first significant scale mark. At this moment, a signal appears at the output of converter 3, which through

0, the pulse shaper 6 is fed to the input of the program block 7, which stops the operation of the motion block 8.

Thus, the opto-electronic converter unit 1 is installed

5 against the first significant mark of the instrument to be checked 19. The speed of movement of the block 1 between the significant marks of the scale should be set so that the completion of transients caused by the flow

0 to the input of the device signals of the stepped form from the model divider 10, occurred within the width of the scale mark.

After stopping block 1, several options are possible.

5 of the instrument with respect to a meaningful scale (Fig. 2a). The first case corresponds to the coincidence of the pointer with the mark, when the light beam, having reflected, hits the input of the converter 2, the signal of which through

0 shaper 5 is fed to the second input of the software block, which means that the device has the maximum permissible measurement error and is valid when checking this mark. Program

5, the block 7 switches the exemplary divider 10 and the motion block 8, which moves to the next significant scale mark.

The second case, when the signal at the second input of program block 7 is missing and

The unit produces on its third output a signal that turns on the CLINE 13 generator (the signal provides, for example, a supply voltage). After that, the signal at the output of the generator 13 (Fig. 26), as well as at the output of the adder 12, begins to increase linearly. At that moment, when a pulse appears at the output of the imaging unit 5, which corresponds to the coincidence of the instrument pointer with the scale mark, the key 15 is triggered and the voltage value at the output of the CLAY 13 is fixed in the display 18 of the results of calibration. It’s easy to estimate the instrument’s accuracy when checking the current significant scale mark. Thus, after the occurrence of the signal at the output of the pulse shaper 5, the result of the verification and adjustment of the setup to the next significant scale mark of the instrument 19 are ensured.

In the third case, when the pointer of the device does not reach the field of view of converter 2 and the voltage at the output of CLAY 13 begins to exceed the voltage of the additional divider 11, then a high level signal appears at the output of the comparator 14, which through the switch 16 turns on the signal No means that the instrument does not comply with metrological requirements, and the instrument rejects.

In the fourth case, when moving block 1, the signal from the instrument pointer first appears, and then from the scale mark, the instrument also rejects.

Thus, the proposed installation allows to increase the reliability of the results of verification, by excluding the possibility of recognizing electrical measuring instruments that do not meet the metrological requirements based on taking into account their dynamic properties. In addition, the proposed installation allows, in contrast to the well-known one, in which only the fact of the validity or unsuitability of the instrument being tested is recorded, to obtain quantitative characteristics of the results of verification, on the basis of which it is possible

analysis of the measurement error distribution on the instrument scale.

Claims (1)

Invention Formula Installation for automatic calibration electrical measuring instruments containing a reference signal source connected in series, an exemplary divider and an adder, in addition, an additional divider, whose input is connected to the output of the reference signal source, two keys, an inverter, and a series-connected optoelectronic converter unit and a dual channel pulse generator, the outputs of which are respectively connected to the inputs of the software unit, the first output of which is connected to the input of the displacement unit, and the second one - with the control input of the model divider, information inputs of the optical-electronic converter unit are connected via the optical channel, respectively, with scale marks and a pointer device, and the control input - with the output of the displacement unit, the input of the inverter is connected to the control input of the first key, and the output - with the information input of the second key, the output is summed. The ra is connected to the terminals to connect calibrated device, characterized in that, in order to increase the accuracy and reliability of the calibration, a linearly varying voltage generator, a comparator and a display unit are introduced into it verification results, the second input of the adder, the first input of the comparator and the input of the first key are connected to the generator output of a linearly varying voltage, the input of which is connected to the additional third output of the program block, the output of the additional divider is connected to the second input of the comparator, the output of which is connected to the control the input of the second key whose output is the output of the installation, the second output of the block of pulse formers is connected to the control input of the first key, the output of which is connected to the input of the block indicating the verification results. Q Ti and iy 2l Q 2