SU1483294A1 - Pressure meter - Google Patents

Abstract

The invention relates to force-measuring technique and makes it possible to increase the accuracy of pressure measurements by reducing the conversion error. For this, along with piezoelectric element 1 with differential plates 2 and 3, connected via switch 4 to exciting generator 5, and indicator 9, the device for measuring pressure contains frequency divider 6, trigger 7 and processing unit 8. Due to the introduction of the frequency divider 6 and the trigger 7, switching of the piezoelectric plates over a fixed number of excitation pulses of the generator 5 is achieved, which reduces the error in converting pressure to pulse duration and thereby increasing the measurement accuracy. 1 hp f-ly, 2 ill.

Description

Phia.1

This invention relates to a force engineering technique and can be used to measure pressure and mechanical forces.

The aim of the invention is to improve the measurement accuracy by reducing the conversion error.

Figure 1 shows the functional diagram of the device for measuring JQ pressure; Fig. 2 is a schematic diagram of the implementation of the processing unit included in its composition.

The device (Fig. 1) contains a piezoelectric element 1 with differential plates 15 and 2 and 3 connected via switch 4 to the exciter generator 5, frequency divider 6, trigger 7,. the processing unit 8 and the indicator 9. The output of the exciting generator 5 through 20 frequency divider 6 is connected to the counting and trigger inputs 7. The direct and inverse outputs of the trigger 7 are connected to the control inputs of the switch 4 and the processing unit 8, the output of which is under-25 keys to the indicator 9.

The processing unit (Fig. 2) contains a high-frequency generator 10, the output of which is connected to the signal inputs of the switches 11 and 12, counters 13 JQ and 14, a driver 15 pulses, a comparison circuit 16 and a third switch 17. The control inputs of the first 11 and second 12 switches are connected to the corresponding inputs of the block 8 about-, 5 workings, the output of which is connected to the output of the third switch 17. The outputs of the first 11 and second 12 switches are connected to the inputs of counters 1,3 and 14, respectively, their reset inputs are connected to one of inputs of block 8 processing cher A shaper 15 pulses, the outputs of the counters 13 and 14 are connected to the corresponding inputs of the comparison circuit 16, the output 45 of which is connected to the control input - the house of the third switch 17, the signal input of which is connected to the output of the generator 10,

A device for measuring pressure -Q works as follows

In the initial state, the first control input of the switch 4 acts a positive impulse, providing a connection, exciting generator 5, through the switch 4, to the differential lining 2 of the piezoelectric element 1 and the excitation of the differential lining 2 of the piezoelectric element, Pulses

The excitation of this area with its resonance frequency is fed to the input of the 6 frequency divider, the output of which is the counting field of the set number of pulses. The signal arrives at the counting input of the trigger 7, which causes the switch 4 to activate and the excitation generator 5 to switch to another differential lining of the piezoelectric element 1. At the same time, a positive pulse from the direct output of the trigger 7 is fed to the first control input 8. of the processing, where its duration is measured. Similarly, when the differential plate 3 of the piezoelectric element 1 is excited, a pulse from the inverse output of the trigger 7 is fed to the second control input of the processing unit 8, where the durations of the mentioned pulses are compared, and the comparison result determined by the measured pressure value is fed to the indicator 9 .

A comparison of the durations of the excitation periods of the differential plates 2 and 3 of the piezoelectric element 1 takes place in the processing unit 8 (Fig. 2) as follows. The high-frequency generator 10 generates pulses arriving at the inputs of the switches 11.1 and 17. Switch I transmits pulses to the counter 13 during the excitation period of the plate 2 of the piezoelectric element 1, and the switch 12 transmits pulses to the counter 14 during the period of excitation of the plate 3 of the piezoelectric element 1, Thus, the switch 17 transmits on indicator 9 a number of pulses proportional to the difference between the mentioned periods.

Due to the fact that the switching / plates of the piezoelectric element is carried out on a fixed number of excitation pulses, the conversion error is reduced and thus the measurement accuracy is improved.

Claims (2)

1. A pressure measuring device containing a piezoelectric element with two differential plates on one metallized end, an indicator and an excitation generator connected to the differential plates through a switch, characterized in that, in order to improve measurement accuracy by reducing the conversion error, equipped with a frequency divider, a trigger and a processing unit, with the output of the driver through a frequency divider connected to the counting trigger input, direct and inverse outputs of the trigger trigger cheny to the control inputs of the switch and the processing unit, whose output is connected to the indicator. 2. The device according to claim 1, wherein the processing unit comprises a high-frequency generator, three switches, two counters, a comparison circuit and a pulse shaper, the high-frequency generator output being connected to the signal inputs of the switches, - the first inputs of the first and second switches are connected to the corresponding inputs of the processing unit, the output of which is connected to the output of the third switch, the outputs of the first and second switches are connected to the inputs of the corresponding counters, the reset inputs of which are connected S to one of the inputs of the processing unit through the pulse shaper, the outputs of the counters are connected to the corresponding inputs of the comparison circuit, the output of which is connected to the control input of the third switch. P 15 Ae /five x u v