CN112461446A - Rapid dynamic vacuum calibration method for vacuum gauge - Google Patents
Rapid dynamic vacuum calibration method for vacuum gauge Download PDFInfo
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- CN112461446A CN112461446A CN202011322918.XA CN202011322918A CN112461446A CN 112461446 A CN112461446 A CN 112461446A CN 202011322918 A CN202011322918 A CN 202011322918A CN 112461446 A CN112461446 A CN 112461446A
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- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L27/00—Testing or calibrating of apparatus for measuring fluid pressure
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Abstract
The invention discloses a rapid dynamic vacuum calibration method for a vacuum gauge, which comprises the steps of firstly, extracting air pressure in a calibration device to a background pressure, and opening a calibrated vacuum gauge and a pressure gauge; then, any one of the obtained multiple calibration gases is filled into the pressure stabilizing chamber until the pressure reaches a pressure threshold value and is stable; secondly, collecting readings of the calibrated vacuum gauge for multiple times by adopting a two-stage expansion static detection method, collecting temperatures of a calibration chamber and a first expansion chamber, dividing airflow states in the two-stage expansion process, and establishing corresponding conductance models for the two expansion processes by adopting a Navier-Stokes equation and a Monte Carlo method respectively; and circularly pumping gas for calibration until all the calibration of various calibration gases is completed, and correcting the calibrated vacuum gauge by combining the temperature of the calibration chamber, the reading of the calibrated vacuum gauge and the corresponding conductance coefficient to reduce the error of the calibration result.
Description
Technical Field
The invention relates to the technical field of vacuum gauge calibration, in particular to a rapid dynamic vacuum calibration method for a vacuum gauge.
Background
The vacuum calibration method by the static expansion method is used as a commonly used method for statically calibrating a vacuum gauge, and the calibration process generally adopts a process mode of expanding gas from a small volume of a sampling chamber to a large volume of a calibration chamber to attenuate standard pressure so as to realize the calibration of the vacuum gauge. In the current static expansion process, the default is a constant temperature state, and the inspection result and the process cannot be mastered, so that the calibration error is large.
Disclosure of Invention
The invention aims to provide a rapid dynamic vacuum calibration method for a vacuum gauge, which reduces calibration errors.
In order to achieve the aim, the invention provides a method for quickly and dynamically calibrating vacuum of a vacuum gauge, which comprises the following steps:
extracting the air pressure in the calibrating device to the background pressure, and opening the calibrated vacuum gauge and the pressure gauge;
filling any one of the obtained multiple calibration gases into the pressure stabilizing chamber until the pressure reaches a pressure threshold and is stable;
collecting readings of the calibrated vacuum gauge for multiple times and collecting the temperature of a calibration chamber by adopting a two-stage expansion static detection method;
correcting the calibrated vacuum gauge in combination with the calibration chamber temperature and the calibrated vacuum gauge reading until all calibrations of the plurality of calibration gases are completed.
Wherein, after acquiring readings of the calibrated vacuum gauge a plurality of times and acquiring the temperature of the calibration chamber using a two-stage expansion static detection method, the method further comprises:
and dividing the airflow state in the secondary expansion process, and establishing corresponding conductance models for the two expansion processes by respectively adopting a Navier-Stokes equation and a Monte Carlo method.
Wherein, adopting a two-stage expansion static detection method, collecting the reading of the calibrated vacuum gauge for multiple times, and collecting the temperature of the calibration chamber comprises:
opening a second valve, enabling the gas in the pressure stabilizing chamber to flow through a first expansion chamber, and acquiring the reading of the calibrated vacuum gauge and the vacuum degrees of the pressure stabilizing chamber and the calibration chamber by using a data acquisition device;
and acquiring temperature values of the first expansion chamber and the calibration chamber at corresponding moments, and recording and storing the temperature values and the corresponding vacuum degrees.
Wherein, after the temperature values at the corresponding moments of the first expansion chamber and the calibration chamber are collected and recorded and stored with the corresponding vacuum degrees, the method further comprises the following steps:
opening a third valve or a fourth valve, enabling the gas in the pressure stabilizing chamber to flow through a second expansion chamber, and acquiring the reading of the calibrated vacuum gauge and the vacuum degrees of the pressure stabilizing chamber and the calibration chamber by using the data acquisition device;
and acquiring temperature values of the second expansion chamber and the calibration chamber at corresponding moments, and recording and storing the temperature values and the corresponding vacuum degrees.
Wherein, until all of the plurality of calibration gases are calibrated, correcting the calibrated vacuum gauge in combination with the calibration chamber temperature and the calibrated vacuum gauge reading comprises:
drawing a corresponding curve according to the corresponding temperature value and the vacuum gauge degree in the collected two-stage expansion process, and correcting the vacuum gauge degree curve by combining the temperature curve.
Wherein, until all of the plurality of calibration gases are calibrated, after correcting the calibrated vacuum gauge in combination with the calibration chamber temperature and the calibrated vacuum gauge reading, the method further comprises:
and rechecking the corrected calibrated vacuum gauge, if the corrected calibrated vacuum gauge still has deviation, recalibrating, and if the rechecking is normal, packaging the corrected calibrated vacuum gauge.
The invention relates to a rapid dynamic vacuum calibration method of a vacuum gauge, which comprises the steps of firstly, extracting air pressure in a calibration device to a background pressure, and opening a calibrated vacuum gauge and a pressure gauge; then, any one of the obtained multiple calibration gases is filled into the pressure stabilizing chamber until the pressure reaches a pressure threshold value and is stable; secondly, collecting readings of the calibrated vacuum gauge for multiple times by adopting a two-stage expansion static detection method, collecting temperatures of a calibration chamber and a first expansion chamber, dividing airflow states in the two-stage expansion process, and establishing corresponding conductance models for the two expansion processes by adopting a Navier-Stokes equation and a Monte Carlo method respectively; and circularly pumping gas for calibration until all the calibration of various calibration gases is completed, and correcting the calibrated vacuum gauge by combining the temperature of the calibration chamber, the reading of the calibrated vacuum gauge and the corresponding conductance coefficient to reduce the error of the calibration result.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a schematic diagram illustrating steps of a method for fast dynamic vacuum calibration of a vacuum gauge according to the present invention.
Fig. 2 is a schematic structural diagram of a calibration apparatus provided in the present invention.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.
In the description of the present invention, it is to be understood that the meaning of "a plurality" is two or more unless specifically limited otherwise.
Referring to fig. 1, the present invention provides a method for fast and dynamic vacuum calibration of a vacuum gauge, comprising the following steps:
s101, extracting the air pressure in the calibrating device to the background pressure, and opening the calibrated vacuum gauge and the calibrated pressure gauge.
Specifically, before calibration, it is necessary to determine whether the current vacuum gauge needs to be calibrated, a known air pressure environment may be created artificially, the vacuum gauge is used for detection, if an error occurs, the current vacuum gauge is considered as a calibrated vacuum gauge, and if no error occurs, calibration is not needed.
And then connecting the calibrated vacuum gauge with a calibration chamber of a calibration device, wherein the structure of the calibration device is shown in fig. 2, extracting gas in the whole calibration device by using an air extraction system until the air pressure in the calibration device is reduced to the background air pressure, then opening the calibrated vacuum gauge and a pressure gauge connected with a pressure stabilizing chamber, and then zeroing the calibrated vacuum gauge and the pressure gauge after the air pressure in the calibration device is stabilized for a period of time, so that errors generated in subsequent measurement can be avoided.
And S102, filling any one of the acquired multiple calibration gases into the pressure stabilizing chamber until the air pressure threshold is reached and stabilized.
Specifically, any one of the acquired multiple calibration gases is filled into the pressure stabilizing chamber until the pressure reaches a pressure threshold and is stable, three inert gases are generally prepared for pressure measurement, the three inert gases do not affect the environment and the device, then one gas is sequentially filled into the pressure stabilizing chamber, when the pressure gauge detects that the pressure in the pressure stabilizing chamber reaches the set pressure threshold, the filling of the gas is stopped, the pressure is maintained for a period of time, and then the measurement is started, so that the stability of the airflow in the pressure stabilizing chamber can be ensured, and the pressure value is ensured to have no deviation.
S103, collecting the reading of the calibrated vacuum gauge for multiple times by adopting a two-stage expansion static detection method, and collecting the temperature of the calibration chamber.
Specifically, first, a first-order expansion was performed, as shown in FIG. 2, with the small black squares on V1a, Vlb, VL and VR representing Pt100 platinum resistance thermometers attached to the outer surface of the vessel, 1 each on V1a and V1b, and 5 each on VL and VR, evenly distributed; VL and VR are the volumes of the two-stage expansion calibration chamber, i.e. when valves 2-9 are closed. V1a, Vlb are the volumes of the first expansion chambers (first left expansion chamber and first right expansion chamber), respectively; however, during the first stage expansion, valves 2 and 3 must be opened (valve 1 closed), thus adding a portion of the conduit volume to VL and VR, and hence the volume of the calibration chamber during the first stage expansion is denoted as V' L and VIR. Closing the first valve, opening a second valve (opening a valve 2 or a valve 3), enabling gas in the pressure stabilizing chamber to flow through a first expansion chamber (V1a or V1b), sampling the gas flowing through the first expansion chamber, and acquiring the reading of the calibrated vacuum gauge and the vacuum degrees of the pressure stabilizing chamber and the calibration chamber by using a data acquisition device; and acquiring temperature values of the first expansion chamber and the calibration chamber at corresponding moments, and recording and storing the temperature values and the corresponding vacuum degrees. Taking the example of the expansion of gas from V1a to V1a + V' L (when valve 3 is open and the rest are closed), the first-stage expansion modification equation is as follows:
wherein in the formula
P0Is the initial pressure of the gas in V1a before the 1 st expansion; p1Is the pressure of the gas in V' L after the 1 st expansion; t is0Is the temperature of the gas in V1a before the 1 st expansion; t1 is the temperature of the gas in V' L after the 1 st expansion.
Opening a third valve (valve 4 or valve 5) or a fourth valve (valve 6 or valve 7), allowing the gas in the pressure maintaining chamber to flow through a second expansion chamber (V2a or V2b, namely a second left expansion chamber and a second right expansion chamber), and acquiring the reading of the calibrated vacuum gauge and the vacuum degrees of the pressure maintaining chamber and the calibration chamber by using the data acquisition device; and acquiring temperature values of the second expansion chamber and the calibration chamber at corresponding moments, and recording and storing the temperature values and the corresponding vacuum degrees. Gas expansion from V1a to V1a + V2a decaV' R (when valves 3 and 5 are open and the remainder are closed) and then from V2a to V2a + VL (when valves 3 and 5 are closed)Valves 4 and 5 alternately open and close), V2a first sample pressure P1(i.e., the pressure generated in V' R by the primary expansion) the secondary expansion correction equation is:
wherein k1 ═ V2a/V1 a; k2 ═ V' R/V1; p0The initial pressure of the gas in V1a before the first expansion; t is0Is the temperature of the gas in V1a before the first expansion; t is2Is the temperature of the gas in V2a (i.e., V' R) after the first stage expansion. The temperature of the gas in V2a is replaced by the temperature of the gas in V 'R because V2a, after sampling V' R, undergoes a second expansion towards VL (in which valves 4 and 5 are alternately opened and closed), which is a relatively short time interval of about 6 seconds. Such a substitution can greatly simplify the calculation.
After taking multiple readings of the calibrated vacuum gauge and taking calibration chamber temperatures using a two-stage expansion static detection method, the method further comprises:
and dividing the airflow state in the secondary expansion process, and establishing corresponding conductance models for the two expansion processes by respectively adopting a Navier-Stokes equation and a Monte Carlo method. In the dynamic vacuum calibration process, when the required calibration pressure is high, the gas flow state in the rapid expansion process can experience different states such as turbulence, transitional flow, viscous flow, transitional flow, molecular flow and the like, and correspondingly, the conductance value can also change significantly. Taking a section of continuous flow phase of turbulent flow and first transition flow state as a first expansion phase, taking a section of thin gas flow phase of viscous flow, second transition flow and molecular flow as a second expansion phase, and establishing a model only aiming at the two sections. And in consideration of the characteristics of the two sections, a Navier-Stokes equation is adopted to obtain a conductance relation model for the continuous flow stage, and a Monte Carlo method is adopted to obtain the conductance relation model for the thin gas flow stage. Thereby improving the accuracy of conductance. The formula for calculating conductance c (t) is:
where τ is the known time constant and V is the corresponding volume.
And S104, correcting the calibrated vacuum gauge by combining the temperature of the calibration chamber and the reading of the calibrated vacuum gauge until all the calibration of the plurality of calibration gases is completed.
Specifically, a corresponding curve graph is drawn according to the corresponding temperature value and the vacuum gauge degree in the collected two-stage expansion process, and the vacuum gauge degree curve is corrected by combining the temperature curve. After the detection of one kind of gas is finished, the air exhaust system is reused for carrying out air exhaust operation on the calibration device, then one kind of gas is replaced for calibration until all the obtained calibration gas is used up, the calibration times of the calibrated vacuum gauge are increased, accidental errors are avoided, and the authenticity and the accuracy of a calibration result are increased.
And rechecking the corrected calibrated vacuum gauge, namely manually creating a known gas environment again, detecting the air pressure by using the calibrated vacuum gauge, recalibrating if the air pressure is still deviated, and packaging the corrected calibrated vacuum gauge if the rechecking is normal, so that the influence on the calibration effect, secondary or multiple calibrations and the efficiency and the result caused by temperature rise or collision is avoided.
The invention relates to a rapid dynamic vacuum calibration method of a vacuum gauge, which comprises the steps of firstly, extracting air pressure in a calibration device to a background pressure, and opening a calibrated vacuum gauge and a pressure gauge; then, any one of the obtained multiple calibration gases is filled into the pressure stabilizing chamber until the pressure reaches a pressure threshold value and is stable; secondly, collecting readings of the calibrated vacuum gauge for multiple times by adopting a two-stage expansion static detection method, collecting temperatures of a calibration chamber and a first expansion chamber, dividing airflow states in the two-stage expansion process, and establishing corresponding conductance models for the two expansion processes by adopting a Navier-Stokes equation and a Monte Carlo method respectively; and circularly pumping gas for calibration until all the calibration of various calibration gases is completed, and correcting the calibrated vacuum gauge by combining the temperature of the calibration chamber, the reading of the calibrated vacuum gauge and the corresponding conductance coefficient to reduce the error of the calibration result.
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (6)
1. A method for quickly and dynamically calibrating vacuum of a vacuum gauge is characterized by comprising the following steps:
extracting the air pressure in the calibrating device to the background pressure, and opening the calibrated vacuum gauge and the pressure gauge;
filling any one of the obtained multiple calibration gases into the pressure stabilizing chamber until the pressure reaches a pressure threshold and is stable;
collecting readings of the calibrated vacuum gauge for multiple times and collecting the temperature of a calibration chamber by adopting a two-stage expansion static detection method;
correcting the calibrated vacuum gauge in combination with the calibration chamber temperature and the calibrated vacuum gauge reading until all calibrations of the plurality of calibration gases are completed.
2. The method for rapid dynamic vacuum calibration of a vacuum gauge of claim 1, wherein after taking multiple readings of the calibrated vacuum gauge using a two-stage expansion static detection method and taking a calibration chamber temperature, the method further comprises:
and dividing the airflow state in the secondary expansion process, and establishing corresponding conductance models for the two expansion processes by respectively adopting a Navier-Stokes equation and a Monte Carlo method.
3. The method for rapid dynamic vacuum calibration of a vacuum gauge of claim 1, wherein the acquiring readings of the calibrated vacuum gauge a plurality of times and the acquiring a calibration chamber temperature using a two-stage expansion static detection method comprises:
opening a second valve, enabling the gas in the pressure stabilizing chamber to flow through a first expansion chamber, and acquiring the reading of the calibrated vacuum gauge and the vacuum degrees of the pressure stabilizing chamber and the calibration chamber by using a data acquisition device;
and acquiring temperature values of the first expansion chamber and the calibration chamber at corresponding moments, and recording and storing the temperature values and the corresponding vacuum degrees.
4. The method for fast dynamic vacuum calibration of a vacuum gauge according to claim 3, wherein after the temperature values at the corresponding time of the first expansion chamber and the calibration chamber are collected and recorded and stored with the corresponding vacuum degree, the method further comprises:
opening a third valve or a fourth valve, enabling the gas in the pressure stabilizing chamber to flow through a second expansion chamber, and acquiring the reading of the calibrated vacuum gauge and the vacuum degrees of the pressure stabilizing chamber and the calibration chamber by using the data acquisition device;
and acquiring temperature values of the second expansion chamber and the calibration chamber at corresponding moments, and recording and storing the temperature values and the corresponding vacuum degrees.
5. The method of claim 4, wherein the step of correcting the calibrated vacuum gauge in combination with the calibration chamber temperature and the calibrated vacuum gauge reading until all of the plurality of calibration gases are calibrated comprises:
drawing a corresponding curve according to the corresponding temperature value and the vacuum gauge degree in the collected two-stage expansion process, and correcting the vacuum gauge degree curve by combining the temperature curve.
6. The method for fast dynamic vacuum calibration of a vacuum gauge of claim 1, wherein after correcting said calibrated vacuum gauge in combination with said calibration chamber temperature and said calibrated vacuum gauge reading until all calibrations of a plurality of said calibration gases are completed, said method further comprises:
and rechecking the corrected calibrated vacuum gauge, if the corrected calibrated vacuum gauge still has deviation, recalibrating, and if the rechecking is normal, packaging the corrected calibrated vacuum gauge.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114674489A (en) * | 2022-03-25 | 2022-06-28 | 中国工程物理研究院材料研究所 | Multifunctional high-vacuum measurement comparison and calibration device and calibration method thereof |
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| DE3025929A1 (en) * | 1979-08-02 | 1981-02-19 | Balzers Hochvakuum | DEVICE FOR CALIBRATING VACUUM METERS |
| CN106500910A (en) * | 2016-12-02 | 2017-03-15 | 山东中检高科检测技术有限公司 | A kind of vacuometer dynamic contrast calibrating installation |
| CN107991020A (en) * | 2017-11-29 | 2018-05-04 | 兰州空间技术物理研究所 | A kind of new Calibration System of Mass Spectrometers for Partial Pressure and method |
| CN111141450A (en) * | 2019-12-26 | 2020-05-12 | 兰州空间技术物理研究所 | Vacuum gauge dynamic characteristic calibration device based on optical interference method |
| CN111220326A (en) * | 2019-12-27 | 2020-06-02 | 兰州空间技术物理研究所 | Calibration device and method for calibrating vacuum gauge by using vacuum leak hole |
-
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- 2020-11-23 CN CN202011322918.XA patent/CN112461446B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3025929A1 (en) * | 1979-08-02 | 1981-02-19 | Balzers Hochvakuum | DEVICE FOR CALIBRATING VACUUM METERS |
| CN106500910A (en) * | 2016-12-02 | 2017-03-15 | 山东中检高科检测技术有限公司 | A kind of vacuometer dynamic contrast calibrating installation |
| CN107991020A (en) * | 2017-11-29 | 2018-05-04 | 兰州空间技术物理研究所 | A kind of new Calibration System of Mass Spectrometers for Partial Pressure and method |
| CN111141450A (en) * | 2019-12-26 | 2020-05-12 | 兰州空间技术物理研究所 | Vacuum gauge dynamic characteristic calibration device based on optical interference method |
| CN111220326A (en) * | 2019-12-27 | 2020-06-02 | 兰州空间技术物理研究所 | Calibration device and method for calibrating vacuum gauge by using vacuum leak hole |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114674489A (en) * | 2022-03-25 | 2022-06-28 | 中国工程物理研究院材料研究所 | Multifunctional high-vacuum measurement comparison and calibration device and calibration method thereof |
| CN114674489B (en) * | 2022-03-25 | 2023-05-12 | 中国工程物理研究院材料研究所 | Multifunctional high-vacuum measurement comparison calibration device and calibration method thereof |
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