SU1620816A1 - Device for measuring areas of flat objects - Google Patents

Abstract

The invention relates to a measurement technique and can be used to measure the areas of flat figures, the areas of flat faces or sections of solids. The purpose of the invention is to improve the measurement accuracy and simplify the device. Drawing a measuring line consisting of alternating conductive strips, conducting a contour of a figure with an unknown area, leads to the appearance of a voltage unbalance at the input of a differential amplifier, which is converted to a frequency. As a result of interrogation of all lines of the measuring line, a frequency value proportional to the area of the measured figure is written into the register in the corresponding code. 1 hp f-ly, 2 ill.

Description

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The invention relates to a measurement technique and can be applied to measure the areas of flat figures (graphic, cartographic, etc.) of the areas of flat faces or sections of solids.

The aim of the invention is to improve the measurement accuracy and simplify the device by eliminating the influence on the measurement result of the physical properties of the object - transparency, electrical conductivity, thickness heterogeneity, as well as the elimination of moving elements of the device - drum, pulling rolls, requiring adjustment depending on the shape and thickness of the measurement object.

FIG. 1 shows a measuring ruler; in fig. 2 is a block diagram of a measuring device.

The device contains a reference signal conditioner 1, which includes a current stabilizer 2, connected via an equivalent resistor He with a resistance equal to the resistance of the unshortened line of the measuring line, measuring line 3 consisting of elements in the form of strips of material with high resistivity, switch 4 to the reference source the voltage E0, the current regulator 2, connected to the equivalent resistor Ne, is connected to one, and the output of the switch 4 to the other input of the comparison unit 5, which represents the differential amplifier, the output of the differential amplifier 5 is connected to the input of the processing unit consisting of a voltage-to-frequency converter 6, and the output of the latter is connected to one of the inputs of the coincidence circuit 7 (logic gate I), the other input of the circuit 7 is connected to the output of the clock generator 8, the output of the latter is also connected to the control input of the switch 4, the output of the coincidence circuit 7 is connected to the counting input of the counter 9, another input whose reset is connected to the zero bus of the switch 4, the outputs of the counter 9 are connected to the information onnymi input register 10, the other input of which is connected to Recording N-th output line of the switch 4, the register 10 outputs connected to the inputs of the decoder 1t, outputs go to the last indicator 12.

The measuring ruler consists of conductors with a low resistivity 13, conductors with a high resistivity 14, a transparent insulating substrate 15. contacts 16. For measuring the conductive contour of a flat figure with

an unknown area is applied to the ruler.

The device works as follows.

When drawing on the measuring line 3 of the conductive contour of a figure with an unknown area, the sections of the lines of the measuring line are short-circuited. This leads to the appearance of voltage imbalance at the input of the differential amplifier 5 at each switching step of the switch 4, which sequentially connects the lines of the measuring line 3 to the circuit connected to the reference source Ј0- Differential amplifier 5 amplifies the difference of the voltage drops across the Ne and the measuring lines line 3 (at each step of switching).

The voltage from the output of the differential amplifier 5 is fed to the input of the voltage to frequency converter 6.

On counter 9, after summing the values of the frequencies at each switching step, the result is

NNN

lFi K2 -2Di, K1 -K2 -lc -2Rxi

thirty

 Ki K2 lc Px

where Ka is the conversion factor of block 6, Ki is the gain of block 5; N is the number of lines of the measuring line 3;

RX - total line resistance

measuring ruler 3 bounded by a conductive circuit;

1C is the stabilization current of the toKa2 stabilizer.

The synchronization of the account with the operation of the switch is carried out using a synchronous generator 8 and a coincidence circuit. The reset of the meter 9 takes place on the zero bus switch 4.

At the N-th switching step of the switch 4, the readings of the counter 9 are written to the register 10 via the write bus. From the outputs of register 10 readings in the corresponding

the code is fed to the inputs of the decoder 11 and further to the indicator 12.

The area of a flat figure bounded by a conductive contour is

 -2li (h%) -Rx v; i 1

where h is the step of the measuring line 3;

li is the length of the shorted part of the i-th line of the measuring line 3;

p is the resistivity of the conductors of the lines of the measuring line 3;

Sc is the cross-sectional area of the conductors of the measuring line 3.

Claims (2)

1. A device for measuring areas of flat objects comprising a measuring ruler connected via a switch to a comparison unit, a reference voltage former connected to a second input of the comparison unit, and a processing unit with an indicator, characterized in that, in order to improve the accuracy and simplify the device , the measuring ruler is made in the form of alternating current. 0 five 0 coping strips, the processing unit is designed as a synchronous generator and serially connected voltage-to-frequency converter, a two-input coincidence circuit, a counter, a memory register and a decoder, the input of a voltage-to-frequency converter is connected to the output of the comparator unit, the output of the synchronous generator is connected to a control input the switch and the second input of the coincidence circuit, the zero input of the counter is connected to the zero output bus of the switch, the N-output bus of which is connected to the input Record of the memory register. 2. The device according to claim 1, characterized in that the reference voltage driver is in the form of a series-connected reference source, current stabilizer and resistor. eleven and