CN111024186B - Microwave level meter step response time measuring device and method - Google Patents
Microwave level meter step response time measuring device and method Download PDFInfo
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- CN111024186B CN111024186B CN201911410366.5A CN201911410366A CN111024186B CN 111024186 B CN111024186 B CN 111024186B CN 201911410366 A CN201911410366 A CN 201911410366A CN 111024186 B CN111024186 B CN 111024186B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
- G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
- G01F23/28—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring the variations of parameters of electromagnetic or acoustic waves applied directly to the liquid or fluent solid material
- G01F23/284—Electromagnetic waves
Abstract
The invention discloses a microwave level meter step response time measuring device and a method, comprising a first simulation plate, a second simulation plate, an electric turntable, a measured microwave level meter and a data acquisition instrument; the positions of the first simulation plate and the second simulation plate are determined according to the beam angle of the measured microwave level meter; the measured microwave level meter is fixedly arranged on the electric turntable; the data acquisition instrument is connected with the measured microwave level meter through a data acquisition line; the data acquisition instrument is connected with a first lead and a second lead, the first lead is connected with a voltage regulator in series and then is connected with a first conductor bar, and the second lead is connected with a second conductor bar. The method can accurately determine the initial time and the termination time of the step response time, and realizes the calibration of the step response time of the microwave level meter.
Description
Technical Field
The invention relates to the field of microwave level meter step response time measurement, in particular to a microwave level meter step response time measuring device and method.
Background
The microwave level meter is a meter for detecting the level position of a material by using the reflection and propagation time of microwaves on the level of the material to be detected, and is similar to a radar, so the microwave level meter is also called as a radar level meter. The antenna emits microwave pulse to the material surface to be measured, and when the microwave pulse is transmitted to the material surface, the microwave is reflected on the material surface due to the difference between the dielectric rate of the material to be measured and air, and the echo is received by the antenna. The time of flight of the microwave pulse from transmission to reception is proportional to the distance from the antenna to the level of the material (fill level). In practical applications, it is also known as a microwave level gauge or a radar level gauge because it is common to measure liquid level.
The step response time is an important dynamic performance indicator of a microwave level gauge, and is defined as the time interval from the instant a step change occurs in an input variable to the instant the output variable first reaches a specified percentage of the difference between a final steady-state value and an initial steady-state value. The specified percentage is generally 90%.
At present, no device and method for measuring the step response time of the microwave level meter exist in China, and inconvenience is brought to product performance verification work. On the other hand, the measurement environment is different due to the difference in the physical properties of the measured parameters, and the method of generating a step is also different, so that the measuring apparatus and method cannot refer to the step response time of other instruments. For example, the measurement environment specified in the national measurement specification JJF 1049-1995 temperature sensor dynamic response calibration is a water flow or air flow environment with a stable flow field and a stable temperature field, the step quantity is temperature, and the step quantity during the step response time measurement of the microwave level meter is a level or an analog quantity of the level.
Disclosure of Invention
Aiming at the technical problems at present, the invention provides a device and a method for measuring the step response time of a microwave level meter, which realize the calibration of the step response time of the microwave level meter and provide guidance for the performance verification of the microwave level meter.
In order to achieve the purpose, the invention adopts the following technical scheme:
a microwave level meter step response time measuring device is characterized by comprising a first simulation plate, a second simulation plate, an electric turntable, a measured microwave level meter and a data acquisition instrument; the measured microwave level meter is fixedly arranged on the electric turntable; the data acquisition instrument is connected with the measured microwave level meter through a data acquisition line; the data acquisition instrument is connected with a first lead and a second lead, the first lead is connected with a voltage stabilizing source in series and then connected with a first conductor bar, and the second lead is connected with a second conductor bar; the first simulation plate and the second simulation plate are arranged on two sides of the measured microwave level meter, and the first simulation plate and the second simulation plate are arranged in a non-parallel mode; when the central line of the measured microwave level meter is perpendicular to the first simulation board, the first conductor bar is in contact conduction with the second conductor bar, and when the central line of the measured microwave level meter is perpendicular to the second simulation board, the first conductor bar and the second conductor bar are in a disconnected state.
Further, the step response time measuring device of the microwave level meter is characterized in that: the first analog board and the second analog board are sized to individually cover a signal beam of the microwave level gauge under test.
Further, the step response time measuring device of the microwave level meter is characterized in that: the distance between the first simulation plate and the measured microwave level meter is not equal to the distance between the second simulation plate and the measured microwave level meter.
Further, the step response time measuring device of the microwave level meter is characterized in that: the center line of the measured microwave level meter passes through the rotation center of the electric turntable.
Further, the step response time measuring device of the microwave level meter is characterized in that: and the second conductor bar is fixedly arranged on the electric turntable.
Further, the step response time measuring device of the microwave level meter is characterized in that: the output voltage value of the voltage regulator is matched with the range of a first channel of the data acquisition instrument; the first lead and the second lead are connected to a first channel of a data acquisition instrument, and the data acquisition line is connected to a second channel of the data acquisition instrument; the time resolution of the data acquisition instrument is better than 1% of the step response time of the measured microwave level meter.
Further, the step response time measuring device of the microwave level meter is characterized in that: the output voltage of the voltage stabilizing source is 24V direct current voltage.
A step response time measuring method of a microwave level meter is characterized in that: the method comprises the following steps:
s1: fixedly mounting the measured microwave level meter on an electric turntable, wherein the central line of the measured microwave level meter passes through the rotation center of the electric turntable;
s2: adjusting the electric turntable and the first simulation board to enable the central line of the measured microwave level meter to be perpendicular to the first simulation board, and recording the distance between the antenna of the measured microwave level meter and the first simulation board as H1; rotating the electric turntable and adjusting the second simulation board to enable the central line of the measured microwave level meter to be perpendicular to the second simulation board, and recording the distance between the antenna of the measured microwave level meter and the second simulation board as H2; the difference between H1 and H2 is the analog level step quantity;
s3: rotating the electric turntable to make the central line of the measured microwave level meter perpendicular to the first simulating plate and the first conductor rod and the second conductor rod to be connected; the data acquisition instrument starts to acquire the output current value of the measured microwave level meter at a high speed;
s4: enabling the electric turntable to rapidly rotate to a position where the central line of the measured microwave level meter is vertical to the second simulation plate, wherein the time required for rotating the electric turntable to generate the simulation level step quantity is less than 10% of the step response time of the measured microwave level meter; in the process, the first conductor bar is disconnected from the second conductor bar, and the voltage signal acquired by the first channel is subjected to sudden change;
s5: after the data recorded by the data acquisition instrument is stable, ending the measurement; the initial time of the step response time of the measured microwave level meter is the voltage signal mutation time recorded by a first channel of the data acquisition instrument, the termination time is the instant time when a current signal recorded by a second channel of the data acquisition instrument reaches 90% of the difference between the final steady state value and the initial steady state value, and the time interval between the initial time and the termination time is the step response time of the measured microwave level meter;
s6: repeating the above operations S3, S4, and S5 for three consecutive measurements; the deviation between the three measured values and the average value of the three measured values is not more than 10 percent, otherwise, the operation is repeated until the requirement is met;
s7: the average value of the three measurements is the step response time of the measured microwave level meter.
Compared with the prior art, the invention has the beneficial effects that:
the method can accurately determine the initial time and the termination time of the step response time, and realizes the calibration of the step response time of the microwave level meter.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention.
FIG. 1 is a schematic view of an initial state of a step response time measuring apparatus of a microwave level gauge according to the present invention;
FIG. 2 is a schematic view of an end state of a step response time measuring apparatus of a microwave level gauge according to the present invention;
FIG. 3 is a schematic diagram illustrating the step response time determination of the step response time measuring device of the microwave level gauge of the present invention.
Reference numbers in the figures: 1. a first simulation board; 2. a second simulation board; 3. an electric turntable; 4. a microwave level meter; 5. a first stub; 6. a voltage regulator source; 7. a first conductive line; 8. a second conductive line; 9. a data acquisition instrument; 10. a first channel; 11. a second channel; 12. a data acquisition line; 13. a second stub.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.
In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.
Referring to fig. 1 and 2, a microwave level meter step response time measuring device comprises a first analog board 1, a second analog board 2, an electric rotating disk 3, a measured microwave level meter 4 and a data acquisition instrument 9; the measured microwave level meter 4 is fixedly arranged on the electric turntable 3; the data acquisition instrument 9 is connected with the measured microwave level meter 4 through a data acquisition line 12; the data acquisition instrument 9 is connected with a first lead 7 and a second lead 8, the first lead 7 is connected with a voltage stabilizing source 6 in series and then connected with the first conductor bar 5, and the second lead 8 is connected with the second conductor bar 13; the first simulation plate 1 and the second simulation plate 2 are arranged on two sides of the measured microwave level meter 4, and the first simulation plate 1 and the second simulation plate 2 are arranged in a non-parallel mode; when the central line of the measured microwave level meter 4 is perpendicular to the first analog board 1, the first conductor bar 5 is in contact conduction with the second conductor bar 13, and when the central line of the measured microwave level meter 4 is perpendicular to the second analog board 2, the first conductor bar 5 and the second conductor bar 13 are in a disconnected state.
Further, the first analog board 1 and the second analog board 2 are sized to individually cover the signal beam of the microwave level gauge 4 under test.
Further, the distance between the first analog board 1 and the measured microwave level gauge 4 is not equal to the distance between the second analog board 2 and the measured microwave level gauge 4.
Further, the center line of the measured microwave level meter 4 passes through the rotation center of the electric turntable 3.
Further, the second conductor bar 13 is fixedly mounted on the electric turntable 3.
Further, the output voltage value of the voltage regulator 6 is matched with the measuring range of the first channel 10 of the data acquisition instrument 9; the first lead 7 and the second lead 8 are connected to a first channel 10 of the data acquisition instrument 9, and the data acquisition line 12 is connected to a second channel 11 of the data acquisition instrument 9; the time resolution of the data acquisition instrument 9 is better than 1% of the step response time of the measured microwave level meter 4.
Further, the output voltage of the voltage stabilizing source 6 is 24V direct current voltage, the output current of the measured microwave level meter is 4mA-20mA, and the beam angle is 14 degrees.
A step response time measuring method of a microwave level meter comprises the following steps:
s1: fixedly mounting the measured microwave level meter 4 and the second conductor bar 13 on the electric rotating disc 3, wherein the central line of the measured microwave level meter 4 passes through the rotating center of the electric rotating disc 3;
s2: adjusting the electric turntable 3 and the first simulation board 1 to enable the central line of the measured microwave level meter 4 to be perpendicular to the first simulation board 1, and recording the distance between the antenna of the measured microwave level meter 4 and the first simulation board 1 as H1; rotating the electric turntable 3 and adjusting the second simulation board 2 to make the center line of the measured microwave level meter 4 perpendicular to the second simulation board 2, and recording the distance between the antenna of the measured microwave level meter 4 and the second simulation board 2 as H2; the difference between H1 and H2 is the analog level step quantity;
s3: rotating the electric turntable 3 to enable the central line of the measured microwave level meter 4 to be vertical to the first simulation plate 1, and at the moment, the first conductor bar 5 is in contact conduction with the second conductor bar 13; the data acquisition instrument 9 starts to acquire the output current value of the measured microwave level meter 4 at a high speed;
s4: the electric rotating disc 3 is rapidly rotated to the position where the central line of the measured microwave level meter 4 is vertical to the second simulation plate 2, and the time required for rotating the electric rotating disc 3 to generate the simulation level step quantity is less than 10% of the step response time of the measured microwave level meter 4; in the process, the first conductor bar 5 is disconnected from the second conductor bar 13, and the voltage signal acquired by the first channel 10 changes abruptly, wherein the time when the voltage signal acquired by the first channel 10 changes abruptly is the time when the second conductor bar 13 just leaves the first conductor bar 5, that is, the time when the voltage signal changes abruptly;
s5: after the data recorded by the data acquisition instrument 9 is stable, ending the measurement; the initial time of the step response time of the measured microwave level meter 4 is the voltage signal mutation time recorded by the first channel 10 of the data acquisition instrument 9, the termination time is the instant time when the current signal recorded by the second channel 11 of the data acquisition instrument 9 reaches 90% of the difference between the final steady state value and the initial steady state value, and the time interval between the initial time and the termination time is the step response time of the measured microwave level meter 4;
as shown in fig. 3, the abscissa is time and the ordinate is signal value.
Initial time: the moment when the voltage signal collected by the first channel 10 changes abruptly;
an initial value, i.e., an initial steady state value, i.e., a signal collected by the second channel 11 at H1;
the termination value, i.e. the final steady state value, i.e. the signal collected by the second channel 11 at H2;
a step value, the difference between the signal collected by the second channel 11 at H2 and the signal collected by the second channel 11 at H1;
and (3) termination time: the moment when the step value reached 90%.
S6: repeating the above operations S3, S4, and S5 for three consecutive measurements; the deviation between the three measured values and the average value of the three measured values is not more than 10 percent, otherwise, the operation is repeated until the requirement is met;
s7: the average of the three measurements is the step response time of the measured microwave level gauge 4.
In the embodiment, the measured microwave level meter 4 is powered by a 24V DC voltage regulator 6, 4mA-20mA current is output, the beam angle is 14 degrees, the included angle between the first analog board 1 and the second analog board 2 is 30 degrees, and the time required by the electric rotary disc 3 to rotate by 30 degrees is 0.013 s. The response time of the microwave level gauge was measured three times and averaged to 0.3 s.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.
Claims (6)
1. A microwave level meter step response time measuring device is characterized by comprising a first simulation plate (1), a second simulation plate (2), an electric rotating disc (3), a measured microwave level meter (4) and a data acquisition instrument (9);
the first analog plate (1) and the second analog plate (2) are sized to cover the signal beam of the microwave level meter (4) to be measured independently;
the distance between the first simulation plate (1) and the measured microwave level meter (4) is not equal to the distance between the second simulation plate (2) and the measured microwave level meter (4);
the measured microwave level meter (4) is fixedly arranged on the electric turntable (3); the data acquisition instrument (9) is connected with the measured microwave level meter (4) through a data acquisition line (12); the data acquisition instrument (9) is connected with a first conducting wire (7) and a second conducting wire (8), the first conducting wire (7) is connected with a voltage stabilizing source (6) in series and then is connected with the first conductor bar (5), and the second conducting wire (8) is connected with the second conductor bar (13); the first simulation plate (1) and the second simulation plate (2) are arranged on two sides of the measured microwave level meter (4), and the first simulation plate (1) and the second simulation plate (2) are arranged in a non-parallel mode; when the central line of the measured microwave level meter (4) is perpendicular to the first simulation board (1), the first conductor bar (5) is in contact conduction with the second conductor bar (13), and when the central line of the measured microwave level meter (4) is perpendicular to the second simulation board (2), the first conductor bar (5) and the second conductor bar (13) are in a disconnected state.
2. A step response time measuring device for a microwave level gauge as claimed in claim 1, wherein: the central line of the measured microwave level meter (4) passes through the rotation center of the electric turntable (3).
3. A step response time measuring device for a microwave level gauge as claimed in claim 2, wherein: the second conductor bar (13) is fixedly arranged on the electric turntable (3).
4. A step response time measuring device for a microwave level gauge as claimed in claim 1, wherein: the output voltage value of the voltage regulator (6) is matched with the measuring range of a first channel (10) of the data acquisition instrument (9); the first lead (7) and the second lead (8) are connected to a first channel (10) of a data acquisition instrument (9), and the data acquisition line (12) is connected to a second channel (11) of the data acquisition instrument (9); the time resolution of the data acquisition instrument (9) is better than 1% of the step response time of the measured microwave level meter (4).
5. A step response time measuring device for a microwave level gauge as claimed in claim 4, wherein: the output voltage of the voltage stabilizing source (6) is 24V direct current voltage.
6. A measuring method of a step response time measuring device of a microwave level gauge according to claim 1, characterized in that: the method comprises the following steps:
s1: fixedly mounting a measured microwave level meter (4) on an electric turntable (3), wherein the central line of the measured microwave level meter (4) passes through the rotation center of the electric turntable (3);
s2: adjusting the electric turntable (3) and the first simulation board (1) to enable the central line of the measured microwave level meter (4) to be perpendicular to the first simulation board (1), and recording the distance between the antenna of the measured microwave level meter (4) and the first simulation board (1) as H1; rotating the electric turntable (3) and adjusting the second simulation plate (2) to enable the central line of the measured microwave level meter (4) to be perpendicular to the second simulation plate (2), wherein the distance between the antenna of the measured microwave level meter (4) and the second simulation plate (2) is recorded as H2; the difference between H1 and H2 is the analog level step quantity;
s3: rotating the electric turntable (3) to enable the central line of the measured microwave level meter (4) to be vertical to the first simulation plate (1), and enabling the first conductor bar (5) to be in contact conduction with the second conductor bar (13) at the moment; the data acquisition instrument (9) starts to acquire the output current value of the measured microwave level meter (4) at a high speed;
s4: the electric rotating disc (3) is rapidly rotated to the position where the central line of the measured microwave level meter (4) is vertical to the second simulation plate (2), and the time required for rotating the electric rotating disc (3) to generate the simulation level step quantity is less than 10% of the step response time of the measured microwave level meter (4); in the process, the first conductor bar (5) is disconnected from the second conductor bar (13), and the voltage signal collected by the first channel (10) changes suddenly;
s5: after the data recorded by the data acquisition instrument (9) is stable, ending the measurement; the initial time of the step response time of the measured microwave level meter (4) is the voltage signal mutation time recorded by a first channel (10) of the data acquisition instrument (9), the termination time is the instant time when the current signal recorded by a second channel (11) of the data acquisition instrument (9) reaches 90% of the difference between the final steady state value and the initial steady state value, and the time interval between the initial time and the termination time is the step response time of the measured microwave level meter (4);
s6: repeating the above operations S3, S4, and S5 for three consecutive measurements; the deviation between the three measured values and the average value of the three measured values is not more than 10 percent, otherwise, the operation is repeated until the requirement is met;
s7: the average value of the three measurements is the step response time of the measured microwave level meter (4).
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| DE102008048582A1 (en) * | 2008-09-23 | 2010-03-25 | Endress + Hauser Gmbh + Co. Kg | Microwave level gauge |
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| US10802111B2 (en) * | 2017-02-06 | 2020-10-13 | Magnetrol International, Inc. | Through air radar level transmitter with measurement of first moving echo |
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| CN101281052A (en) * | 2007-04-02 | 2008-10-08 | 周建明 | High precision low-power consumption radar liquid level instrument system |
| US10068467B1 (en) * | 2011-08-31 | 2018-09-04 | E. Strode Pennebaker, III | System and method for field monitoring of stationary assets |
| WO2018158578A1 (en) * | 2017-03-01 | 2018-09-07 | University Of St Andrews | Classification method and device |
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