2022 Vol. 66, No. 5

Display Method:
Design and Performance Research of Preparation Device for Ultra-Wide Concentration Radioactive Reference Gas DT
ZHU Wenhui, LIU Chang, YUE Weihong, WU Zhanhua, QU Yantao
2022, 66(5): 3-7. doi: 10.12338/j.issn.2096-9015.2021.0664
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To meet the testing and calibration requirements of the flow-through tritium ionization chamber, radioactive reference gas DT with different activity concentrations should be prepared. With the aid of the tritium-containing heavy water moderator and resin purification system in the CANDU6 reactor of Third Qinshan Nuclear Power Co., Ltd., the moderator activity concentration was obtained by liquid scintillation counting measurement-electrolysis method, and the hydrogen isotope abundance of the electrolytic gas was analyzed by mass spectrometry, and with the implementation of the PVT exponential dilution method, a preparation device for ultra-wide concentration radioactive reference gas DT was developed. The device was designed with a catalytic-oxidation-liquid scintillation counting verification unit and an exhaust gas collection-reuse processing unit, while isotope infiltration and inner wall electroplating and other measures were adopted for sample preparation to reduce the adsorption-memory effect on the device wall. The device has the advantages of small size, wide activity concentration range, low adsorption effect of low concentration DT, low cross-contamination, and low uncertainty. The prepared radioactive reference gas DT has an activity concentration range from 4.0×104~1.0×1014 Bq/m3 at the standard state, which can meet the needs of different types and applications of flow-through tritium ionization chamber testing and calibration in China.
Research on Prediction of Stability of Torque Sensor Based on Neural Network
MENG Chen, JIANG Jile, GUO Bin, WU Kun, WU Shi
2022, 66(5): 8-14, 68. doi: 10.12338/j.issn.2096-9015.2021.0633
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In torque verification, the fluctuation of torque value over time is not a known common function, and it is vital to explore the trend of its change and fluctuation for torque verification and dissemination of value of quantity. To explore the fluctuation characteristic of the torque sensor, the influence of medium- and long-term stability on the change of torque value in torque measurement is investigated, and a neural network is used to train the detection data under given conditions to predict the torque value at other time points. The torque value data obtained under strictly controlled experimental conditions for the last 12 years were used for training and analysis, the accuracy and reliability of the model were demonstrated by cross-validation, the torque value of the next calibration cycle was predicted, and the probability that the torque value of the next cycle meets the long-term stability of 0.03 level was finally calculated to be greater than 71.8%.
Performance Study of BeO Optically Simulated Luminescent Dosimetry System for Hp(10) Measurement
ZHANG Xuan, LI Dehong, HUANG Jianwei, LIU Bo, LI Dongyang
2022, 66(5): 15-18, 60. doi: 10.12338/j.issn.2096-9015.2021.0656
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To grasp the metrological performance indicators of the BeO optically stimulated luminescent (OSL) dosimetry system and verify whether it meets the needs of personal dose monitoring, the OSL dosemeter containing BeO optically stimulated luminescent detectors was placed in and irradiated with X-ray and γ-ray reference radiation fields. Performance test research on nonlinear response, coefficient of variation, energy response, angular response, and repeatability were carried out for the personal dose equivalent Hp(10). The nonlinear response ranged from 0.92 to 1.05 in the dose range of 50 μSv to 1 Sv, and the coefficient of variation ranged from 0.55% to 4.8%. The energy response ranged from 0.71 to 1.01 in the energy range of 33 keV to 1.25 MeV. The angular response ranged from 0.97 to 1.22 in the range of 0° to ±75° angle of incidence. The irradiation dose of 1 mSv, 5 mSv and 10 mSv were repeated 8 times, and the corresponding dose repeatability were 0.99 - 1.00, 0.99 - 1.00 and 0.97 - 1.00, respectively. The results showed that the BeO OSL dosimetry system meets the requirements of the IEC 62387-2020 standard and can be used for personal dose monitoring.
Effective Selection and Application of Ethanol Characteristic Spectrum in Gasoline
LI Ke, LU Bing, DU Biao, LU Xiaoxin, LIU Zhe, LI Qingwu, ZHANG Zhengdong
2022, 66(5): 19-24. doi: 10.12338/j.issn.2096-9015.2021.0631
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Near-infrared spectroscopy rapid analysis is one of the main methods to detect the ethanol content in gasoline, and the selection of the spectrum is an important factor affecting the prediction accuracy of the rapid detection model. In this study, a rapid analysis method of near-infrared spectroscopy based on an effective characteristic spectrum was established to improve the accuracy of detection of ethanol content in gasoline. By comparing the near-infrared spectra of gasoline with different concentrations of ethanol content, the effective characteristic spectrum of ethanol molecules in gasoline was determined to be 4524.183~5044.869 cm−1 and 5985.961~7108.329 cm−1. The optimal pre-processing method for near-infrared spectroscopy was chosen, and modeling analysis was carried out using the full-spectrum and effective characteristic spectrum. The relevant parameters of the model established using the effective characteristic spectrum are as follows: the root-mean-square error of cross-validation (RMSECV) is 0.5849, the internal cross-validation correlation coefficient (${{R}}_{\text{CV}}^{\text{2}}$) is 0.9991, the root-mean-square error of prediction (RMSEP) is 0.6090, and the external verification correlation coefficient (${{R}}_{\text{P}}^{\text{2}}$) of the prediction set is 0.9989. Compared with the full-spectrum modeling analysis, the RMSECV was reduced by 30.27 %, and the RMSEP was reduced by 18.58%. In conclusion, the quantitative analysis model established by using the characteristic spectrum has higher accuracy and can meet the need for rapid analysis of ethanol content in gasoline.
Comparative Study on Total Radiant Flux Measurement of Near-UV LEDs
ZHAO Weiqiang, LIU Hui, YAN Jinyun, SU Ying
2022, 66(5): 25-28. doi: 10.12338/j.issn.2096-9015.2021.0635
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Total radiant flux is one of the technical indicators to characterize the radiation properties of near-UV LEDs, which can be derived by measuring the total spectral radiant flux (TSRF). In recent years, the National Institute of Metrology has carried out research on the measurement technology of TSRF, and established a standard device for measuring the TSRF ranging from 350 to 1100 nm. To verify the reliability of the uncertainty assessment in the near-UV region, the TSRF and total radiant flux values of near-UV LEDs were measured using a TSRF standard measurement device and a self-built horizontal goniospectroradiometer, respectively. The comparison shows that the values obtained by the two technical approaches are consistent within the uncertainty range. The uncertainty assessment of the TSRF standard measurement device in the near-UV region is reasonable and the values are reliable.
Research on Data Processing Method Based on Automatic Measurement System of Mass in Small Nominal Value
PENG Cheng, WANG Jian, WANG Xiaolei, WU Di, ZHONG Ruilin, HU Manhong
2022, 66(5): 29-36. doi: 10.12338/j.issn.2096-9015.2021.0648
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To improve measurement efficiency, calibration laboratories are gradually employing automatic measurement systems instead of manual measurements. At present, the data directly generated by the automatic measurement system focuses on the presentation of the measurement results but lacks the key information elements required by ISO-17025 for the original records and certificate reports. In the meantime, when carrying out mass measurements in small nominal values, it is easy to generate incomplete data due to measurement interruptions caused by falling weights. After the measurement, it is often necessary for inspectors to process data manually. Therefore, in the actual inspection work, the data analysis and processing of the automatic measurement system still require a lot of manpower. In this paper, combined with the features of mass measurements in small nominal value, a data analysis and processing method based on the automatic measurement system was proposed. Functions such as automatic segmentation and reorganization of data, identification of unqualified results, and processing of incomplete data were added. reduces the interference of human factors. The method realized automatic analysis of data, automatic generation of original records and certificate reports, reduced human factor interference, and further enhanced the efficiency of quality inspection and automatic data processing and analysis.
Performance Evaluation of Wearable ECG Monitoring Devices
ZHOU Feng, DING Xiang, ZHANG Lei
2022, 66(5): 37-40. doi: 10.12338/j.issn.2096-9015.2021.0536
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At present, there is a lack of specific metrology technology regulations for wearable ECG monitoring devices. In this paper, the performance evaluation method of wearable ECG monitoring devices is studied based on the standards and metrology technology methods of relevant traditional ECG medical devices. Six types of wearable ECG monitoring and measuring devices from different manufacturers were measured by using wearable ECG simulators to explore the performance evaluation method of such devices. The results showed that through the above-mentioned means, the accuracy of the main performance parameters of the wearable ECG monitoring device can be evaluated to a certain extent through the above ways, and the traceability of some parameters can be realized.
Error Analysis of Angle Measurement by Laser Gyro Goniometer
2022, 66(5): 41-48, 68. doi: 10.12338/j.issn.2096-9015.2021.0599
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With the gradual maturity of the laser gyro manufacturing process and the breakthrough of lock-in and other major issues, the laser gyro goniometer has become a high-precision and high-sensitivity multi-parameter goniometer. This paper carries out a comprehensive test for its metrological performance for the first time and analyzes the main error sources of the laser gyro goniometer in detail, including three main error sources such as the installation error of the laser gyro, the turntable unlevel error, and the unstable error of the rotating speed. The simulation and estimation of the error introduced by each factor are analyzed. The random error of the laser gyro goniometer is also analyzed by using the classical Allan variance method. The results show that the uncertainty of comprehensive angle measurement is 0.4 ", and the angle measurement error is better than ± 0.5″.
Study and Analysis of Yoke Loss of Single Sheet Tester for Magnetic Properties Measurement of Electrical Steel
CHEN Chuan, SONG Wentao, ZHOU Xinhua
2022, 66(5): 49-54. doi: 10.12338/j.issn.2096-9015.2021.0575
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Single sheet tester is conventional equipment for measuring the magnetic properties of electrical steel, the measurement methods have been well defined by the national standard GB/T 13789-2008 (IDT IEC 60404-3:2002) “Methods of measurement of the magnetic properties of magnetic sheet and strip by means of a single sheet tester”. With the development of new high-grade products with domain refinement, thin gauge, and low losses, the requirements for the performance of measurement equipment continue to increase, and the additional losses generated by the yoke of the single sheet tester during actual measurement is a problem that cannot be ignored. The current national standards only point out that the yoke should be made with low and constant losses, but no specific treatment is required for the additional losses generated by the yoke. This paper studied the measuring method of the loss generated by the yoke of a single sheet tester and analyzed its effect on the measuring result of the magnetic properties of electrical steel based on the data of yoke loss for different points of magnetic polarization, the method of deducting the yoke loss is given accordingly.
Comparison of Air Kerma Values of X-Ray at 60 ~ 250 kV Therapeutic Level in China
ZHAO Rui, WU Jinjie, WEN Yuqin, SONG Fei, HAN Lu, YAN Yongqiang, LV Yazhu
2022, 66(5): 55-60. doi: 10.12338/j.issn.2096-9015.2021.0585
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Radiotherapy level ionization chamber dosimeter is the main measuring instrument for radiotherapy in hospitals, and it is also the national compulsory verification measuring instrument. The accuracy of its dose measurement is the key carrying out precision radiotherapy. To ensure the accuracy and unity of the quantity value, from 2019 to 2020, National Institute of metrology, China, as the leading laboratory, organized the national comparison of the 60 ~ 250 kV X-ray air kerma. A total of 11 laboratories participated in the comparison, and all reference laboratories established 60 kV, 100 kV, 135 kV, 180 kV, and 250 kV reference radiation. The calibration factor and measurement uncertainty under different radiation were obtained by calibrating two transfer standard ionization chambers in the radiation field using the petal comparison method. The comparison results show that the normalized deviation of each reference laboratory is less than 1, and the comparison results are satisfactory.
Comparative Analysis of the Measurement Capability of VOR Parameter
NIE Meining, ZHANG Yongmei, JIANG Wei, LI Xin, ZHANG Zilong, TIAN Fei, HE Zhao
2022, 66(5): 61-68. doi: 10.12338/j.issn.2096-9015.2021.0613
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Very high frequency omnidirectional range (VOR) is an important radio signal in the field of aviation navigation, and its phase parameters are used to characterize the bearing information. In this paper, the basic principle of VOR signal and the measurement method of azimuth are introduced, and the comparison results of VOR phase parameters in 6 reference laboratories in China are given. The evaluation of domestic VOR phase parameter measurement capability is completed, which lays a foundation for ensuring the uniformity of quantity and value of aviation navigation parameters in China.
Demand Analysis and Implications for Collection Development in Response to U.S. Export Controls
SHANG Xueshen, LIU Yitong, LI Li, YANG Caijun, LI Xiaomeng, ZHANG Yu
2022, 66(5): 69-72, 24. doi: 10.12338/j.issn.2096-9015.2021.0638
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In this paper, we investigated the technology list and entity list of U.S. export control, based on which we conducted demand analysis on literature resources for institutions included in the entity list, and sorted out the literature that has been restricted from ordering. It is found that the majority of the restricted literature are conference proceedings, mostly from the two sensitive fields, military technology and nuclear technology, with the largest proportion of U.S. publications. Accordingly, recommendations on collection development such as increasing the collection rules for special literature, developing special literature data from a wide number of sources, further expanding the types of collection resources, and shifting the focus of collection resources from quantity to precise and comprehensive resource discovery are proposed. Finally, the competitive situation and challenges of science and technology faced by China, and the importance and strategic guarantee role of metrology science and technology literature in metrology research and innovation are analyzed.