CN101451943B - Quartz crystal microbalance accuracy verification test system - Google Patents

Abstract

The invention relates to a quartz crystal microbalance accuracy test device, which includes an in-situ real-time weighing system in a degassing chamber, a cosine quantitative scattering system for degassed objects, and an angle coefficient inspection system; the in-situ real-time weighing system in the degassing chamber realizes degassing Real-time measurement of material mass change, the measured value can be traced back to the national mass measurement standard through the calibrated electronic balance; the outgassing cosine quantitative scattering system transfers the quantitative mass of the order of 10 ^-4 g to the surface of the quartz crystal microbalance through the quantitative scattering method The quantitative mass areal density of the order of 10 ^-7 g/cm ² realizes the quantitative loading of the quartz crystal microbalance, and its loading measurement accuracy can be traced back to the quality benchmark of the superior and the national metrology system; the angle coefficient inspection system is used for Verify the accuracy of the view coefficient of the scattering system to ensure the control of the entire mass transfer process. The accuracy test system of the present invention has high test accuracy, and the uncertainty is better than 40%. It adopts the real-time direct weighing of the outgassing object under vacuum, and realizes the accurate measurement of the outgassing rate.

Description

Quartz crystal microbalance accuracy verification test system

technical field

The invention relates to a quartz crystal microbalance accuracy verification test system, which belongs to the technical field of material outgassing pollution testing. the

Background technique

In the process of spacecraft production, the quartz crystal microbalance pollution test is the main means to determine the environmental pollution of spacecraft development. Quartz crystal microbalances have been applied to various stages of spacecraft development. Quartz crystal microbalances have been used to measure environmental pollution in the stages of spacecraft component development and testing, spacecraft assembly testing, spacecraft thermal testing and mechanical testing. Therefore, effective pollution control measures are proposed to ensure that the development of spacecraft meets the requirements of pollution control. the

However, there is currently a lack of verification and calibration test equipment and verification specifications for quartz crystal microbalances in China. The measurement accuracy of quartz crystal microbalances cannot be traced back to the national metrology verification system, which affects the reliability of the measurement results of quartz crystal microbalances. It can no longer meet the requirements of long life and high reliability of spacecraft. At present, there is no relevant domestic manufacturer to carry out research and development in this area. In foreign countries, Lockheed Palo Alto Research Laboratories of the United States has developed an accuracy analysis test device for commercial quartz crystal microbalances. It is based on the thermodynamic properties of water and uses the saturated vapor pressure parameters of water to obtain the evaporation of water in a certain environment. Velocity; obtains the velocity of mass reaching the surface of a quartz crystal microbalance based on the theory of scattering and transport in molecular vacuum. These quartz crystal microbalances are controlled at liquid nitrogen temperature. Water molecules that reach the surface of the balance are almost completely absorbed. The measurement accuracy of a quartz crystal microbalance is traced to the accuracy of the evaporation rate of water in a certain environment. Since the evaporation rate of water is affected by multiple factors in the environment, especially the instability of the thermal conductivity seriously affects the accuracy of the evaporation rate of water, the foreign accuracy analysis test device cannot achieve high accuracy, and the measurement is not accurate. The degree of certainty is greater than 80%. the

For this reason, it is very necessary to develop a high-accuracy quartz crystal microbalance accuracy verification test system. the

Contents of the invention

The object of the present invention is to provide a measurement accuracy test system of quartz crystal microbalance that has higher accuracy and can be traced back to the national quality measurement standard. the

The technical scheme of the present invention is as follows: Quartz crystal microbalance measurement accuracy test system, including the in-situ real-time weighing system of the degassing chamber, the cosine quantitative scattering system of the degassed object, and the angle coefficient inspection system; the in-situ real-time weighing system of the degassing chamber The real-time measurement of the mass change of the outgassing substance is realized, and the measured value can be traced back to the national quality measurement standard through the calibrated electronic balance; the cosine quantitative scattering system of the outgassing substance transfers the quantitative mass of the order of 10 ^-4 g to the quartz crystal trace through the quantitative scattering method The quantitative mass areal density of the order of 10 ^-7 g/cm ² on the surface of the balance realizes the quantitative loading of the quartz crystal microbalance, and the measurement accuracy of the loading amount can be traced back to the quality benchmark of the superior and the national metrology system; the angle coefficient inspection system , used to verify the accuracy of the view coefficient of the scattering system and ensure the control of the entire mass transfer process.

In the above system, the in-situ real-time weighing system of the degassing chamber includes a calibrated electronic balance, an electronic balance loading and unloading device, a degassing chamber, and a temperature control device for the degassing chamber. The calibrated electronic balance directly weighs the deflation chamber in real time, and the electronic balance loading and unloading device realizes the zero reset of the calibrated electronic balance to ensure the accuracy of weighing. The temperature control device of the deflation chamber performs non-contact temperature control on the deflation chamber, and the quality value of the deflation chamber is transferred to the quality value of the deflation object, thereby realizing the transfer of the quality value. the

In the above system, the outgassing cosine quantitative scattering system includes outgassing, a scattering device, and a deposition surface. The gas released by the outgasser passes through the scattering system and reaches the deposition surface. The degassing chamber in the in-situ real-time weighing system transmits the mass value of the degassing rate of the degassing material in the degassing chamber, and the scattering device converts the mass value into the mass surface density value on the deposition surface. The accuracy of mass areal density values can be traced upwards to national mass measurement benchmarks. the

In the above system, the angle factor inspection system includes a calibrated electronic balance, an electronic balance loading and unloading device, and a deposition amount inspection plate. The calibrated electronic balance directly weighs the deposition amount inspection plate in real time, and the electronic balance loading and unloading device realizes the reset of the calibrated electronic balance to ensure the accuracy of weighing. The deposition amount inspection plate accepts the deposition of the same mass area density as the deposition surface in the outgassing cosine quantitative scattering system, and this mass area density is weighed by the mass of the electronic balance, so as to realize accurate verification of the scattering system. By increasing the amount of outgassing, the deposition amount of the deposition amount inspection plate is greater than 10 ^-4 g, which meets the weighing range requirements of the calibrated electronic balance.

Among them, the electronic balance in the in-situ real-time weighing system of the degassing chamber and the electronic balance of the loading and unloading device have a weighing resolution of 10 ^-5 g.

Further, the cosine diffusion method adopted by the outgassing cosine quantitative scattering system can realize 1/1000 mass equalization. the

Compared with the prior art, the present invention has the following advantages:

(1) The mass transfer process of the present invention is fully controlled, and the in-situ real-time weighing system of the deflation chamber transfers the accuracy of the national quality standard to the accuracy of the deflation rate, and the deflated cosine quantitative scattering system and the view coefficient inspection system will The accuracy of the outgassing rate is transferred to the measurement of the quartz crystal microbalance. the

(2) The test accuracy of the present invention is high, and the uncertainty is better than 40%, and the real-time direct weighing of the outgassing object under vacuum is adopted to realize the accurate measurement of the outgassing rate. the

Description of drawings

Fig. 1 is a block diagram of the present invention;

Fig. 2 is the real-time weighing system block diagram of deflation chamber in situ of the present invention;

Fig. 3 is the block diagram of outgassing object cosine quantitative scattering system of the present invention;

Fig. 4 is a block diagram of the view coefficient inspection system of the present invention;

Fig. 5 is the test flow of the present invention. the

Detailed ways

As shown in Figure 1, the in-situ real-time weighing system 1 of the degassing chamber of the quartz crystal microbalance measurement accuracy test system provides the quantitative value of the degassing rate of the degassed substance for the cosine quantitative scattering system 2 of the degassed substance, and the quantitative value The accuracy can be traced back to the national mass measurement standard. The outgassing cosine quantitative scattering system 2 converts the 10 ^-4 g mass value into a 10 ^-7 g/cm ² mass surface density value, and provides it to the measured quartz crystal microbalance 4 , to realize the quantitative mass loading on the surface of the quartz crystal microbalance; the view coefficient inspection system 3 inspects the accuracy of converting the mass value into the mass surface density value in the outgassing cosine quantitative scattering system 2, and this accuracy can be traced back to the national quality measurement standard.

As shown in FIG. 2 , the in-situ real-time weighing system 1 of the deflation chamber of the present invention includes a calibrated electronic balance 11 , an electronic balance loading and unloading device 12 , a deflation chamber 13 , and a temperature control device 14 for the deflation chamber. The calibrated electronic balance 11 directly weighs the deflation chamber 13 in real time, and the electronic balance loading and unloading device 12 realizes the reset of the calibrated electronic balance 11 to ensure the accuracy of weighing. The deflation chamber temperature control device 14 performs non-contact temperature control on the deflation chamber 13 , and the mass value of the deflation chamber 13 is transferred to the mass value of the deflation object 21 , realizing the transfer of the mass value. the

As shown in FIG. 3 , the outgasser cosine quantitative scattering system 2 of the present invention includes an outgasser 21 , a scattering device 22 , and a deposition surface 23 . The gas released by the gasser 21 passes through the scattering device 22 and reaches the deposition surface 23 . The degassing chamber 13 in the in-situ real-time weighing system 1 transmits the mass value of the degassing rate of the degassed object 21 , and the scattering device 22 converts the mass value into the mass areal density value on the deposition surface 23 . The accuracy of mass areal density values is traceable back to national mass measurement benchmarks. the

As shown in FIG. 4 , the view factor inspection system 3 of the present invention includes a calibrated electronic balance 31 , an electronic balance loading and unloading device 32 , and a deposition amount inspection plate 33 . The calibrated electronic balance 31 directly weighs the deposition amount inspection plate 33 in real time, and the electronic balance loading and unloading device 32 realizes the reset of the calibrated electronic balance 31 to ensure the accuracy of weighing. The deposition amount inspection plate 33 accepts the deposition of the same mass areal density as the deposition surface 23 in the outgassing cosine quantitative scattering system 2 , and this mass areal density is weighed by the electronic balance 31 , so as to realize accurate verification of the scattering system. By increasing the outgassing amount, the deposition amount of the deposition amount inspection plate 33 is greater than 10 ⁻⁴ g, which meets the weighing range requirements of the calibrated electronic balance 31 .

As shown in FIG. 5 , in the test flow of the present invention, it is first selected to perform the verification test of the view factor or the verification test of the accuracy of the quartz balance. According to the needs of the test, install the deposition amount inspection board or quartz crystal microbalance, then install the outgassing material, and weigh the initial value of the outgassing object, and at the same time weigh the deposition amount inspection board or record the initial value of the frequency of the quartz crystal microbalance , and then start the outgassing scattering test process. After the test is completed, weigh the outgasser again, and at the same time weigh the deposition amount inspection plate again or record the final value of the frequency of the quartz crystal microbalance. Determine the view factor and accuracy of the quartz crystal microbalance from weighing and recording results. the

Although the specific implementation of the present invention has been described and illustrated in detail above, it should be pointed out that we can carry out various changes and modifications to the above-mentioned embodiments, but these do not depart from the spirit of the present invention and the appended rights Request the range described. the

Claims (6)

1. Quartz crystal microbalance measurement accuracy test system, including the in-situ real-time weighing system (1) of the outgassing chamber, the cosine quantitative scattering system (2) of the outgassing object, and the view coefficient inspection system (3); among them, The in-situ real-time weighing system (1) of the degassing chamber (1) calibrated electronic balance (11), electronic balance loading and unloading device (12), degassing chamber (13), and degassing chamber temperature control device (14); The balance (11) directly weighs the deflation chamber (13) in real time, and the electronic balance loading and unloading device (12) realizes the reset of the electronic balance (11) to ensure the accuracy of weighing; the temperature control of the deflation chamber The device (14) performs non-contact temperature control on the deflation chamber (13), and the quality value of the deflation chamber (13) is transferred to the quality value of the deflation object (21), thereby realizing the transfer of the quality value; The outgasser cosine quantitative scattering system (2) includes an outgasser (21), a scattering device (12), and a deposition surface (13); the gas released by the outgasser (21) passes through the scattering system (22) and reaches the deposition surface (23); the deflation chamber (13) in the deflation chamber in-situ real-time weighing system (1) transmits the mass quantity value of the deflation rate of the deflation object (21), and the scattering device (12) transfers the mass value The value is converted into the mass areal density value on the deposition surface (23); the accuracy of the mass areal density value can be traced back to the national quality measurement benchmark; Described view factor inspection system (3) comprises electronic balance (31), electronic balance loading and unloading device (32), deposition amount inspection board (33) through calibration; Described electronic balance (31) directly real-time to deposition amount inspection board (33) carry out weighing, electronic balance loading and unloading device (32) realizes the accuracy of weighing through the reset of calibrated electronic balance (11) guarantee weighing; (2) The deposition of the same mass surface density of the deposition surface (23) in (2), which is weighed by the electronic balance (31), thereby realizing accurate verification of the scattering system; by increasing the amount of outgassing, the deposition amount checks the plate (33) The deposition amount is greater than 10 ⁻⁴ g, meeting the weighing range requirements of the calibrated electronic balance (31). 2. The system according to claim 1, characterized in that, the in-situ real-time weighing system (1) of the degassing chamber realizes the real-time measurement of the change of the degassed substance amount, and its measured value can be traced back to the country through a calibrated electronic balance. quality measurement benchmark. 3. system as claimed in claim 1, is characterized in that, described outgassing thing cosine quantitative scattering system (2) transfers the quantitative quality of 10 ⁻⁴ g order of magnitude to 10 on the quartz crystal microbalance surface by quantitative scattering method Quantitative mass areal density of ^-7 g/cm ² order has realized the quantitative loading of quartz crystal microbalance, and its loading measurement accuracy can be traced back to the quality benchmark of the superior and national metrology system. 4. system as claimed in claim 1, is characterized in that, described view coefficient checking system (3), is used for verifying the accuracy of scattering system view coefficient, guarantees the control of whole mass transfer process. 5. The system according to any one of claims 1-4, characterized in that: the electronic balance (11) and its loading and unloading device (12) in the in-situ real-time weighing system (1) of the deflation chamber The weighing resolution of the electronic balance is 10 ^-5 g. 6. The system according to any one of claims 1-4, characterized in that: the cosine diffusion method adopted by the outgassing cosine quantitative scattering system can realize 1/1000 mass equalization.

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