SU1716387A1 - Apparatus for measuring liquid bulk strength - Google Patents

Abstract

The device relates to a technique for determining the physical properties of materials and can be used, for example, to determine the bulk strength of substances in flowing form. The aim of the invention is to improve the measurement accuracy. An additional hermetic chamber formed by the surface of a mercury poured into an additional U-tube, and an unfilled volume of an additional U-tube with a crane, the opposite end of which is connected to a loading device, as well as an analog-digital converter, an indicator, an additional volume sensor, are inserted into the device. , control unit and measurement unit. The control unit contains the generator, the first delay element, the trigger, the first-third comparators, the first-sixth elements And, the first-third counters and the first-third digital-to-analog converters. The measurement unit contains the OR element, the fourth, the fifth and the sixth counters, the setpoint adjuster, the fourth – seventh digital-to-analogue converters, a voltage divider, the fourth and fifth comparators, the second delay element, the NOT element, and the seventh element I. 2 zp f-ly, 3 ill. (Ls

Description

The invention relates to a technique for determining the physical properties of materials and can be used, for example, to determine the bulk strength of substances in flowing form.

A known method for measuring the volumetric strength of a liquid and the device implementing it is that the liquid under investigation is stretched by increasing the volume, and the bulk strength is judged by the measured values of the tensile force at the moment of breaking the liquid. In this case, the stretching is carried out through an intermediate fluid that is chemically neutral with respect to the test fluid, mainly through mercury, by applying a force that increases with a constant velocity. In addition, the gas is stretched under identical conditions, and the tensile force at the moment of liquid rupture is determined by the intersection point of the measured dependencies. The buffer liquid is preliminarily evacuated. A device for measuring volumetric strength that implements the method comprises a hermetic variable-volume chamber with a locking element for the liquid to be tested, as well as a loading device and an indicator of the movement of the liquid under investigation. In addition, the device contains a cocyfli connected at one end to a hermetic chamber of variable volume, and the loading device is connected to the chamber through a buo

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The ferric fluid is equipped with a unit for providing an increase in force at a constant speed and a unit for fixing the change in the volume of the test liquid and the tensile force. A sealed chamber is formed by the surface of a mercury poured into a U-shaped tube and an empty volume of a U-shaped tube with a tap. The loading device is designed as a vacuum pump. The fixation unit of the change in the volume of the test liquid and the tensile force is applied in the form of electrical displacement sensors and pressure, the outputs of which are connected to a two-coordinate recording device.

However, the known method and device have not sufficiently high metrological characteristics. As follows from the description of the method and device, in their application it is necessary to use special graphs, which in itself is associated with a loss of accuracy both in the construction of graphs and in the use of them. In addition, for each study of a particular fluid, you must first conduct an experiment and construct the required graph. However, the use of graphs corresponding to the properties of one of the fluids in the study of another fluid is illegal and can lead to a significant error in the estimate. .

The purpose of the invention is to improve the measurement accuracy by taking into account the specific properties of the test liquid.

To achieve this goal, an additional sealed chamber, formed by the surface of a mercury poured into an additional U-shaped tube, and an unfilled volume of a U-shaped tube with a tap, the opposite end of which is connected to the loading device, is inserted into the device. Also, an analog-digital converter, an indicator, an additional volume sensor, a control unit and a measurement unit, the first input of which is directly connected to the first input of the control unit —and through the button is connected to the output of the source, eg the second and fourth inputs and the first-third outputs of the control unit are connected to the output of the volume sensor, the second output of the measuring unit, the output of the additional volume sensor, and the second to the fourth inputs of the measuring unit, respectively, the fifth input of the control unit and the first input of the analog-to-digital converter, the second input and the group of outputs of which are connected to the first output of the measuring unit and the group of indicator inputs, respectively.

The control unit contains the generator, the first delay element, the trigger, the first-third comparators, the first - the sixth elements And, the first-third counters and the first-third. digital-to-analog converters, with the input of the first delay element connected to the first input of the block

0 and the zero inputs of the trigger and the first

-three counters, and its output is connected to a single trigger input, the output of which is connected to the first inputs of the fourth to sixth elements And, the first and second inputs

5 and the outputs of the first-third comparators are connected to the second, third and fifth, block inputs, outputs of the first-third digital-to-analog converters and the first inputs of the first-third elements

0 And, respectively, the second and third inputs of the first and third elements And are connected to the fourth input of the block and the generator output, respectively, the second inputs of the fourth and sixth elements And are connected to

5 output of the first element And the counting input of the first counter, with the output of the second element And the counting input of the second counter and the output of the third element l / l and the counting input of the third counter

0, respectively, the groups of outputs of the first and third counters and the outputs of the fourth and sixth elements And are connected to the groups of inputs of the first and third digital-to-analogue converters and the first and third outputs of the unit, respectively.

The measurement block contains the OR element, the fourth — the sixth counters, the gauge, the fourth — the seventh digital-to-analogue converters, divide the voltage,

0 fourth and fifth comparators, the second delay element, the element is NOT and the seventh element is AND, the first and second inputs and output of the element OR are connected to the first input of the block, the output of the second element

5 delays and zero inputs of the fourth to sixth counters, respectively. counting inputs and output groups of the fourth

- the sixth counters are connected to the second - fourth inputs of the block and the groups of inputs of the fourth - the sixth digital-to-analogue converters, respectively, the group of inputs of the seventh digital-to-analogue converter is connected to the group of outputs of the setter, and its output is connected to the first

5 to the fourth comparator input, the second input of which is connected to the output of the fourth digital-to-analog converter, and the output to the first input of the seventh element AND and the inputs of the NOT element and the second delay element, the input of the voltage divider connected to the output of the sixth digital-analog converter, and its output connected to the first input of the fifth comparator, the first input and output of which are connected to the output of the fifth digital-analog converter and the second input of the seventh And element, respectively, the outputs of the seventh And element and the element Do not form the first and second outputs of the block, respectively.

The invention differs from the prototype in that it compares the specific increments of the volumes of liquids in the test volume and in the control volume, in which the bulk strength has obviously already occurred, with identical stretching. This provides an automatic measurement of the specific increments of the volumes of the test and the volume of the control and their comparison. The coincidence, with a given accuracy of these specific increments, indicates a violation of the bulk strength of the test liquid. The value of tensile force, measured at the time of the breach of the volume strength of the liquid, and characterizes the measured value. In addition to a significant reduction in labor costs for measurement, achieved by automating the measurement process, its accuracy is significantly increased, since account- ing; specific properties are tested | liquid and there is no need to build and use graphs characterizing the specific increments of the test and control volumes. .. v

FIG. Figure 1 shows a block diagram of a device for measuring the volume reading of a liquid; in fig. 2 and 3 are structural diagrams of the control unit and the measurement unit included in its composition, respectively.

Device for measuring volumetric. The strength of the fluid (Fig. 1) contains a U-shaped tube 1 and an additional U-shaped tube 2, on one side which terminate in taps 3 and an additional tap 4, respectively. Directly beneath the additional valve 4 is the volume 5, which forms when the bulk strength of the fluid in the complementary U-shaped tube 2 is broken. Directly under the valve 3 in the tube 1 and under the volume of gas 5 in the additional tube 2 the test fluid 6 and 7 respectively. Below the test liquid, tube 7 and additional tube 2, mercury is located 8 and 9, respectively; The second ends of the tube 1 and the additional tube 2 are connected by a pipe 1.0. which through the throttle valve 11 and

ver 12 are connected to a vacuum pump 13. On sections of tube 1 and additional tube 2, within which the surface of mercury 8, 9 moves during the measurement, on the border with vacuum (on the side of the pipeline 10) volume sensors 14 and an additional sensor are placed

15 volume. The pressure in line 10 is automatically measured by a 16 gauge. In addition, the rate of change of this pressure and its value are monitored visually from the variometer 17 and the man-vacuum 18. The pressure in the receiver 12 is controlled by a pressure sensor 19. A crane 20 is used to restore the normal pressure in the pipeline 10. And the associated elements are used. The electronic elements of the device are reset using the button 21. The analog-to-digital converter 22 reads the tensile value forces at the time of violation of the bulk strength of the liquid. Indicator 23 highlights the measurement result. The control unit 24 controls the operation of the measurement unit 25, which generates a command pulse to the analog-to-digital converter 22 at the time of the breakdown of the bulk strength of the liquid.

The control unit 24 (Fig. 2) is included; generator 26. forming a series of rectangular pulses of stable frequency; the first delay element 27, which provides for the delay of the issuing of the permitting potential by the trigger 28: the trigger 28, which controls the output of pulses to the outputs of the block; the first, second and third comparators 29, 30 and 31, which compare the voltages at the inputs of the block with the voltages at the outputs of the corresponding digital-to-analog converters; the first, second and third elements And 32, 33 and 34, controlling the passage of the pulses of the generator 26 to the counting inputs of the block counters; the first second and third counters 35, 36 and 37, summing the pulses applied to the counting inputs; the first, second, and third digital-to-tax converters 38, 39, and 40, which form voltages proportional to the codes of the corresponding block counters; the fourth, fifth and sixth elements And 41. 42 and 43, emitting pulses, purely proportional to the increments of pressure and volume measured by sensors

16 pressure sensor, volume sensor 14 and additional volume sensor 15, to the output of control unit 24.

Measurement unit 25 (Fig. 3) contains: an OR 44 unit connecting the circuits along which the Emboss pulses of the block are transmitted; the fourth, fifth and sixth counters 45, 46 and 47, summing the input pulses of the block; unit 48, which stores the specified code for the increment of the tensile force, after which the next test of the safety of the bulk strength of the fluid is performed; the fourth - the seventh digital-to-analog converters 49-52, which form voltages proportional to the codes of the block counters and the setpoint adjuster 48, respectively; a voltage divider 53 decreasing the voltage of the sixth digital-to-analog converter 51 by a required amount to more accurately measure the moment of failure of the bulk liquid strength; the fourth comparator 54, which determines the required times of the next check of the safety of the bulk strength of the liquid; the fifth comparator 55, which determines the moment of violation of the bulk strength of the liquid; the second delay element 56 defining the time for the next analysis of the state of the test liquid; the HE element 571 forming a control voltage applied to the fourth input of the control unit 24 for stopping the operation of its elements for the duration of the analysis; the seventh element And 58, issuing the command to turn on the analog-digital converter 22 at the moment of breaking the bulk strength of the liquid.

The device (Fig. 1) works as follows.

At the stage of its preparation for operation, the valve 3 and the additional valve 4 are opened and the test liquid 6 and 7 are respectively poured into the U-shaped tube 1 and the additional U-shaped tube 2 so that its level is higher than the locking elements of the cranes 3 and 4. Close the additional valve 4, the throttle valve 11 and the valve of the discharge line 20, leave the valve open 3. The vacuum pump 13 creates a vacuum in the receiver, which is visually controlled with a manovacimeter 19. After the required vacuum has been created, open the throttle valve 11- s This rate of increase in the tensile force, controlled by the variometer 17, and the tensile force itself are measured with a man-vacuum meter 18. Visually monitor the speed of movement of the meniscus of mercury 9 and reveal the point in time when, at a constant rate of increase of the stretching force, the speed of movement mercury meniscus 9 increases dramatically. This indicates a violation of the volumetric strength of the fluid in the additional U-shaped tube 2, which can also be confirmed by the appearance of a fluid rupture under the additional valve 4. Opening the valve 20 and adjusting the position of the throttle valve 11 increases the pressure in the pipeline 10 to a value that excludes the possibility of bulk strength of liquid 7 in an additional U-shaped tube 2.

Directly at the stage of measuring the volumetric strength of a liquid, the discreteness of the increment of the tensile force in determining the bulk strength is set first of all. For this purpose, a code for the magnitude of the tensile force is entered into the setting unit 48 of the measurement unit 25, after reaching which the next analysis of the safety of the bulk strength of the liquid is carried out. Then add the test liquid through the valve 3 to the level above the locking element of this valve. The valve 3, the throttle valve 11, the valve 20 of the main line are closed, and the additional valve 4 is closed. Again, a vacuum pump 13 creates a vacuum in the receiver 12 controlled by a visual manovacumeter 19. Pressing the button 21 delivers the resolving potential to the first inputs of the unit 24 control and measurement unit 25, drive them to the initial state before measurement. After the required vacuum has been created, the throttle valve 11 is opened and the predetermined growth rate of the tensile force, controlled by the variometer 17, is set, and the tensile force itself is visually monitored by a manovacimeter 18. The volume sensor 14, the additional volume sensor 15 and the pressure sensor 16 generate voltages proportional to parameters controlled by them; and feed them to the corresponding inputs of the control unit 24. This unit, through its three outputs to the second, third and fourth inputs of the measurement unit 25, produces pulses, the number of which is proportional to the corresponding increment of the tensile force, the volume increment in the U-shaped tube 1 and the volume increment in the additional U-shaped tube 2. These pulses are summed up counters of measurement unit 25. The moment of the next analysis of the preservation of the volumetric strength of a liquid in a U-shaped tube begins after the increment of tensile force exceeds the value of the code recorded in the setting device 48. At the same time, the increments of volumes in tube 1 and in additional tube 2 are compared. 6 retained its volumetric strength, the volume increment measured by the volume sensor 14 will be known

less volume increments, measured by an additional volume sensor 15. The measurement unit will detect this and issue a control voltage to conduct the next analysis cycle.

Comparison of the increments of the volumes of liquids b and 7 continues until, after the next given sufficiently small increment of the tensile force, the increments of the volumes of the liquid in the tube 1 and the additional tube 2 are the same with the specified tolerance. Upon detecting such a situation, measurement unit 25 outputs a command pulse to the second input of the analog-to-digital converter 22. With this command, a tensile force is measured, at which the bulk strength of the fluid was broken. Indicator 23 highlights the measurement result ..

The operation of the control unit 24 (Fig. 2), when measured, begins with zeroing of the trigger 28 and the first, second and third counters 35 36. 37 by applying the enabling voltage to the first input of the block. After a period of time sufficient to bring the block elements back to their original state, and after removing the voltage from the first input of the block by allowing voltage from the output of the first element: 27 delay, trigger 28 returns to the unit state. The fourth, fifth, and sixth elements are opened by the resolving potential from its output. And 41, 42, 43. During the operation of the block, codes are formed in the first, second, and third counters 35, 36, 37, whose values are proportional to the output voltages pressure sensor 16, volume sensor 14, and additional volume sensor 15. For this purpose, the potentials from the outputs of these counters are controlled by the first, second, and third digital-analogs, respectively.

1 converters 38, 39, 40, at the outputs of which voltages are formed, proportional to the counter codes. These voltages are supplied to the second inputs of the first, second, and third comparators 29, 30, 31, the first inputs of which are supplied by the voltages of pressure sensor 16, volume sensor 14, and additional volume sensor 15. Therefore, if at the inputs of any of the comparator it turns out that the voltage of the corresponding digital-to-analog converter is less than the voltage of the sensor, then the output potential of the second inputs of either the first or second or third elements is imparted to the output of this comparator. And 32. 33, 34. On the first input, these elements are controlled by the potential from the fourth input.

the block, and their third inputs are constantly fed with pulses from the output of the generator 26. With the permitting potentials, the first inputs of these elements (i.e., while monitoring the increments of the tensile force and the volume of liquids 6, 7) and the second inputs (tons that is, when the voltage of the voltage sensors at the outputs of the corresponding digital-to-analog converters is exceeded, the pulses from the output of the generator 26 are transmitted to the summing inputs of the first, second and third counters 35, 36, 37, matching their codes and voltages to the outputs of the corresponding digital-to-analog converters STUDIO to stresses on the sensor outputs. At the same time, these equalizing pulses, characterizing the voltage increments at the sensor outputs, are transmitted through the fourth, fifth and sixth elements And 41, 42, 43 to the first, second and third outputs of control unit 24.

The measurement unit operates as follows (Fig. 3).

When preparing the device for operation, the voltage from the button 21 through the first input of the measurement unit 25 is applied to the first input of the element OR 44, the second input of which supplies the output voltage of the second delay element 56 .: The fourth, fifth and sixth counters are brought to this voltage 45, 46, and 47. When pulses arrive at the second, third, and fourth inputs of the block, they are transmitted to the counting inputs of counters and summed by them. The potentials of the outputs of the counters and the setting device 48. control the fourth to the seventh digital-to-analog converters 49-52. The fourth comparator 54 compares the output voltages of the fourth and seventh digital-to-analog converters 49 and 52. If the voltage at the output of the fourth digital-to-analog converter 49 as a result of increasing the sum of the fourth counter 45 becomes greater than the voltage at the output of the seventh digital-analogue converter 52, this means that the increment grows the force-givting liquid has reached the value when a regular analysis of the safety of the bulk strength of the liquid is required. At the output of the fourth comparator 54, The potential that is applied to the inputs of the HE element 57, the second delay element 56 and the first input of the seventh element And 58. The HE element 57 inverts it and, in the form of a forbidding voltage, passes it through the second output of the block to the fourth input of the control unit 24, the analysis time of the passage of the generator pulses 26 through the first, second and third elements 32, 33, 34 to the block counters. The second delay element 56 delays the resetting of the counters of the measurement unit 25 for the time required for the analysis. The seventh element And 58 opens at the first entrance. If, at the same time, there is no permitting potential at its second inlet, then this means that a violation of the bulk strength of the liquid has not yet occurred. The control pulse to the first output of the block is not given. After a period of time determined by the parameters of the second delay element 56, the counters of the measurement unit 25 are reset. The voltage at the output of the fourth digital-to-analog converter 49 becomes lower than the voltage at the output of the seventh digital-analog converter 52. At the output of the fourth comparator 54, a forbidding potential appears, and therefore the resolution potential from the output of the HE element 57 is fed through the second output of the measurement unit 25 to the fourth control unit 24 input. A new cycle for estimating the increment of the liquid-exerting force and subsequent analysis begins.

If, by the time of the next analysis, the voltage at the output of the fifth digital-to-analog converter 50 exceeds the voltage reduced by a given value by the voltage divider 53 at the output of the sixth digital-analog converter 51, then this means a violation of the bulk strength of the liquid, since the specific volume the increment of the volume of the investigated liquid turned out to be with the required tolerance equal to the specific increment of the volume of the same liquid with a violation of the bulk strength. This will lead to the appearance of a resolving pressure. april at the output of the fifth comparator 55. It is transmitted to the second input of the seventh element And 58 and during the next analysis is output to the first output of the unit 25 of measurement. As previously noted, this control voltage includes an analog-to-digital converter 22, which measures the value of the force of a liquid at the moment its bulk strength is broken. Indicator 23 highlights the measured value.

Thus, the accuracy of measurement using the proposed device is increased due to the uselessness of using any graphs; by taking into account the specific features of the test liquid, used both as a test and as a reference. In addition, due to the substantial automation of the measurement process, it is possible to repeatedly

repeat the experiment and therefore. improve measurement accuracy. Certain possibilities of improving measurement accuracy are provided by the introduction.

voltage divider 53, by changing the division factor of which one can more accurately determine the moment of violation, the bulk strength of the liquid.

Claims (3)

Invention Formula 0 1. A device for measuring the volumetric strength of a liquid, containing a sealed chamber located between the valve and the surface of the mercury located at one end of the U-shaped tube to the other 5 the end of which is connected via a volume sensor; a loading device in the form of a series-connected pipeline, a throttle valve, a receiver and a vacuum pump, to the output of which an additional pipeline with a crane is connected, as well as a variometer, a pressure gauge and a pressure sensor connected to the other end of the U-shaped tube , and an additional mano vacuum gauge associated with the receiver, which is so that, in order to improve the measurement accuracy, an additional U-shaped tube is inserted into it, at one end of which is placed additional airtight chamber between the 0 by the surface of the pipe and an additional valve, the other end of the additional U-tube is connected via an additional volume sensor to the loading device, as well as analog-digital 5 converter, indicator, control unit and measurement unit, the first input of which is directly connected to the first input of the control unit and through the button is connected to the voltage source, the second 0 - the fourth inputs and the first - the third outputs of the control unit are connected respectively to the output of the volume sensor, the first output of the measuring unit, the output of the additional volume sensor and the second through four inputs of the measuring unit, the fifth input of the control unit is connected to the output of the pressure sensor and the first analog input - a digital converter, the second input and the group of outputs of which are connected respectively to the second output of the measuring unit and the group of inputs of the indicator. 2. Device pop. 1, characterized in that the control unit comprises a generator, a first delay element, a trigger, 5, the first to the third comparators, the first to the sixth And elements, the first to the third counters and the first to the third digital-to-analog converters, the input of the first delay element being connected to the first input of the block and the connecting terminals of the trigger and the first -three counters, and the output of the delay element is connected to a single trigger input, the output of which is connected to the first inputs of the fourth to sixth elements  And, the first and second inputs and outputs of the first - the third comparators are connected to the second, third and fifth inputs of the unit; the outputs of the first - third digital-to-analog converters and the first inputs of the first - third elements And, respectively, the second and third inputs of the first - third elements And are connected respectively to the fourth input of the unit and the generator output, the first inputs of the fourth - sixth elements And are connected respectively to the outputs of the first - third element The groups of outputs of the first and third meters are connected respectively to the groups of inputs of the first and third digital-to-analog converters, and the outputs of the fourth and sixth elements AND are associated with the first and third outputs of the unit, respectively. The outputs of the first and third elements are connected respectively to counting inputs of the first - third counters. 3. The device according to claim 1, that is, the measuring unit contains the element OR, the fourth — the sixth counters, the setting knob, the fourth — the seventh digital-analog converters, the divider, etc., the fourth and fifth comparators. the second delay element, the NOT element, and the seventh AND element, latching the first and second inputs and the output of the OR element, are respectively connected to the first input of the block, the output of the second delay element, and the zero inputs of the fourth to sixth counters, respectively, counting inputs and output groups of the fourth to sixth counters are connected to the second - fourth inputs of the block and groups of inputs of the fourth - sixth digital-analog converters, respectively, a group of inputs, the seventh digital-analog converter is connected to the output group in the setpoint, and the output of the seventh digital-to-analog converter is connected to the first input of the fourth comparator, the second input of which is connected to the output of the fourth digital-to-analog converter, and the output of the fourth comparator is connected to the first input of the seventh And element and the inputs of the NOT and the second delay element; the voltage divider is connected to the output of the sixth digital-analogue converter; its output is connected to the first input of the fifth comparator, the second input and output of which are connected respectively to the output ohm fifth DAC s second input of the seventh AND gate, respectively, the outputs of the seventh AND gates and NOT element form a first unit and a second outputs, respectively. S-so "9 Fig.Z