2022 Vol. 66, No. 8

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2022, 66(8): 1-1.
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Research on Split Test Method of Low-Pressure High-Flow Thermal Gas Mass Flowmeter
Joseph W.F. Lai, LING Guangsheng, ZHAO Hao, ZHANG Fuyuan, XIE Dailiang, XU Ya
2022, 66(8): 3-6, 12. doi: 10.12338/j.issn.2096-9015.2021.0215
Abstract(751) HTML (281) PDF(35)
Thermal gas mass flowmeter has many advantages, such as large range ratio, high precision, and reliability. It can be widely used in the measurement of industrial natural gas, household gas, and oxygen in medical treatment. It has a broad application prospect in industrial and civil fields. At present, the maximum flow rate of low-pressure natural gas practical flow measurement standard device is usually only 40 m3·h−1, which is unable to test the low-pressure high-flow gas mass flowmeter, bringing a lot of inconvenience to the production. In this paper, the thermal gas mass flowmeter is modified by using the split flow component, and the flow field characteristics of the split flow component and the whole meter are compared and verified by numerical simulation. The practical flow test equipment is used to carry out the practical flow test of the split flow component, and the flow rate performance of the flowmeter is obtained by using the flow proportional coefficient obtained by calculation, thus solving the practical flow test problem of the low-pressure high-flow gas mass flowmeter.
Development of Alpha-Arbutin Certified Reference Material
LI Shuo, ZHANG Nan, LIU Zhe, LI Qingwu, LI Li, WANG Haiyan, SUN Lei, ZHANG Zhengdong
2022, 66(8): 7-12. doi: 10.12338/j.issn.2096-9015.2021.0595
Abstract(538) HTML (276) PDF(63)
Using high purity α-arbutin reagent as raw material, the reference material was further identified and confirmed by MS/MS, IR, UV-vis, nuclear magnetic resonance, melting point, optical rotation, etc.. The chromatographic purity of α-arbutin reference material was determined by High-Performance Liquid Chromatography (HPLC) coupled with fluorescence detector (FLD). Moisture and ignition residue determination was carried out according to the guideline specified in Volume IV of the Pharmacopoeia of the People's Republic of China 2020 Edition. The residual solvents were determined according to the procedure specified in the Safety and Technical Standards for Cosmetics. The purity of α-arbutin reference material was then calculated by the mass balance method and the certified value of α-arbutin is 99.87% with an expanded uncertainty of 2.46% (k=2). The homogeneity and short-term stability tests were carried out with HPLC-FLD after packaging. The results showed that the α-arbutin reference material has the characteristics of high purity, accurate value, and stability, which can provide technical support to cosmetics quality and safety tests in China.
Development of Portable Time Interval Measuring Instrument for Liquid Flow Standard Devices
BI Xiaolong, XING Chao, WU Bo, GUAN Honghui, BI Chongsheng
2022, 66(8): 13-17. doi: 10.12338/j.issn.2096-9015.2022.0086
Abstract(515) HTML (134) PDF(37)
The timing accuracy of the timing system directly affects the final flow measurement result of liquid flow standard devices, which requires regular maintenance and calibration. The traditional timing verification system is often bulky and difficult to carry and transport. It is generally integrated with the measurement and control system, difficult to disassemble and send for inspection, and lacks the calibration interface suitable for the experimental characteristics of flow standard device. In view of the limitations of the existing timing system verification methods, a portable time interval measuring instrument was designed and developed for the instantaneous flow method liquid flow standard devices, which can measure the time interval range from 1 μs to 10000 s, with measurement accuracy of 10 μs, display resolution not less than 1μs, and the accuracy is not less than 1.0×10−6. The performance verification experiment was carried out based on the hot water flow standard facility of China National Institute of Metrology, and the test results showed that: The relative error of the timing system is better than 0.0024 %, and the relative error of the time interval measuring instrument is better than 4.2×10−7 and its repeatability is better than 1.82×10−7. 10 μs, the display resolution is not less than 1μs, and the accuracy is not less than 1.0×10−6. The performance verification experiment was carried out based on the hot water flow standard facility of China National Institute of Metrology, and the test results showed that: The relative error of the timing system is better than 0.0024%, and the relative error of the time interval measuring instrument is better than 4.2×10−7 and its repeatability is better than 1.82×10−7. Its timing accuracy is high and its performance is stable and reliable, which can effectively meet the verification and testing requirements of the timing system of the liquid flow standard facility. It also plays a positive role in improving the measuring capacity of liquid flow facility and the development of liquid flow measurement technology in the future.
LabVIEW-Based Coal Quality Test Data Transmission System
LV Jinhua, YAN Lixin, YUE Yuanpeng, FENG Zhimin, LIU Huiting
2022, 66(8): 18-25. doi: 10.12338/j.issn.2096-9015.2021.0646
Abstract(467) HTML (181) PDF(52)
Combined with IoT technology, a LabVIEW-based coal quality test data transmission system is designed. This system consists of hardware and software. The hardware adopts a two-level data processing method to reduce the resource occupancy. The test data from the serial port of the instrument is packaged at the first level of the system and sent to the second level for data processing, and then packaged into a cloud database. The main function of the software is to view and save data, and to initialize the lower machine. Through the test experiments in the laboratory environment, the results show that the system can upload data accurately in real time. The system is helpful to solve the problems of poor timeliness and low accuracy of data uploading for traditional coal quality testing instruments in thermal power generation industry, and has good application prospects.
Development of PLC-Based Control System for Weight Automatic Verification Devices
CHEN Xue, LUO Xin, YAO Mingshu, ZHANG Siran
2022, 66(8): 26-31. doi: 10.12338/j.issn.2096-9015.2021.0060
Abstract(518) HTML (437) PDF(77)
Aiming at the problems of low efficiency, accuracy, and poor reproducibility of manual measurement of weight quality, the workflow of weight measurement, stability of mass comparator, motion control of three-dimensional manipulator, and positioning accuracy of loading and unloading were studied. The basic principle of the Programmable Logic Controller (PLC) servo control system was analyzed, and a set of PLC-based control system for weight automatic verification devices was designed and developed. Taking CX programmer as the development platform, the control system was established by using PLC and ladder diagram programming language, which realized the automatic control of the whole process of weight loading and unloading and the automatic detection of weight quality. The overall debugging and experimental verification of the system were also carried out. The results showed that the control system has the advantages of simple structure, high efficiency, and avoiding human error, and improves the automation level and reliability of weight verification.
Development of Calibration Auxiliary Device for Remote Sensing Measurement System of Vehicle Exhaust
JIN Peiyu, YAO Jinling, LI Liying
2022, 66(8): 32-36. doi: 10.12338/j.issn.2096-9015.2022.0016
Abstract(362) HTML (180) PDF(43)
With the increasing number of motor vehicles, exhaust pollution has become the focus of attention, and it is crucial to scientifically manage the excessive emissions of motor vehicle exhaust pollutants and strengthen motor vehicle exhaust detection. The remote sensing measurement system of vehicle exhaust combined Tunable Diode Laser Absorption Spectroscopy (TDLAS), Differential Optical Absorption Spectroscopy (DOAS), and automatic identification technology, which can realize online remote sensing measurement of exhaust pollutant concentration during the driving process of motor vehicles without affecting the normal driving conditions. To fulfill the requirements of JJF 1835-2020 “Calibration Specification for Remote Sensing Measurement Systems of Vehicle Exhaust”, a new auxiliary device for calibration has been developed, which is used for static and dynamic calibration of gas measurement indication error with standard gas and has achieved good results. This paper comprehensively introduced the working principle, device composition, and software and hardware design of the auxiliary device for gas calibration.
Design of Dynamic Calibration Device for Non-Combustibility Test Furnace of Building Materials
LI Ming, ZHU Guijun, WANG Wei, WANG Ao
2022, 66(8): 37-41, 31. doi: 10.12338/j.issn.2096-9015.2022.0032
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To ensure the accuracy and reliability of the test results, a set of dynamic calibration device for non-combustibility test furnace of building materials was designed and developed through the study of the temperature distribution model of the test furnace. The device adopted thermocouple high-temperature detection and temperature compensation technology to realize the dynamic temperature detection of the test furnace, and the servo motor and sliding platform were designed to realize the sensor automatic positioning in the high-temperature furnace. The LabVIEW data processing technology and touch screen design were equipped to achieve calibration data processing and calibration results output. The developed calibration device was tested and its performance met the design requirements. The verification results of the calibration of each parameter of the test furnace were within the range specified by the standard, and the calibration uncertainty met the requirements for value transmission.on.
Development of Clamping System for Automatic Calibration of Angle Encoder
2022, 66(8): 42-45, 49. doi: 10.12338/j.issn.2096-9015.2022.0020
Abstract(549) HTML (191) PDF(60)
Using the full-circle continuous angle standard device developed by the National Institute of Metrology as the standard angle generator, a two-dimensional slideway clamping system was developed to fix the encoder stator, and the data acquisition software was developed based on LabVIEW to realize the automatic calibration of hollow shaft angle encoder. The clamping system solved the problem of manual positioning difficulty caused by high starting torque and provides continuous automatic calibration in the 360° full-circle range, which improves the testing efficiency and reduces the sources of uncertainty. The encoder repeatability is better than 0.8″ after the clamping system is configured.
Measurement and Analysis of Electrical Conductivity Parameters of Hemodialysis Machine
GU Jiayu, FANG Shuai, PANG Kan, CAO Jiuying
2022, 66(8): 46-49. doi: 10.12338/j.issn.2096-9015.2022.0023
Abstract(715) HTML (635) PDF(56)
The dialysate concentration is generally expressed by the dialysate conductivity monitoring value, and its accuracy and stability are the guarantees for the patient to achieve adequate dialysis treatment. According to the national metrology technical specifications, the conductivity parameters of hemodialysis machines in medical institutions in Jiangsu province were tested using a hemodialysis machine tester. The results showed that the qualified rate of hemodialysis machine conductivity parameter detection was 99.9%. By analyzing and discussing the reasons for the inaccuracy of conductivity, this paper provided a reference for the clinical management of hemodialysis machines in hospitals at all levels.
Preparation and Magnetoresistive Properties of Tungsten Telluride Magnetoresistive Materials Based on Silver Doping Method
CAO Mingxing, WU Tong, XU Dinghua, HE Jian
2022, 66(8): 50-56. doi: 10.12338/j.issn.2096-9015.2021.0624
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Tungsten telluride magnetoresistive material has an excellent unsaturated magnetoresistance effect, and information storage technology and magnetic sensor fabrication technology based on tungsten telluride magnetoresistive materials represent an important direction in magnetoresistive research. The magnetic and electrical properties of materials can be changed by doping methods. To explore whether tungsten telluride magnetoresistive materials can obtain excellent performance by the silver doping method, a detailed introduction of how to choose the doping method and why choose silver as the doping element is discussed. A method for mild preparation of bulk silver-doped tungsten telluride (WTe2/Ag) magnetoresistive materials was established, namely a novel self-flux sintering method. Three typical WTe2/Ag materials with different silver doping contents were prepared. The characterization and evaluation of phase, valence state, structure, and magnetoresistance performance were tested and analyzed. The results indicated the excellence of the silver doping method, the prepared WTe2/Ag not only has reliable material quality but also effectively enhances the magnetoresistance effect, making it easier to achieve the control conditions for the highest value of the magnetoresistance tested. The measured magnetoresistance is 502.3% at 5 K and 14 T, which is 50% higher than that without doping. The magnetoelectric performance is greatly improved compared with those of doped other elements, which is of positive significance for the optimal design and practical application of electromagnetic devices.
Research on Calibration Method and Uncertainty Evaluation of Handheld Laser-Induced Breakdown Spectrometer
FU Chuan
2022, 66(8): 57-60. doi: 10.12338/j.issn.2096-9015.2022.0001
Abstract(904) HTML (512) PDF(82)
The development and application of handheld laser-induced breakdown spectrometers are introduced in this paper. Due to the lack of corresponding metrological technical specifications for this type of equipment, a metrological calibration method for handheld laser-induced breakdown spectrometers is proposed. The main metrological characteristics include detection limit, indication error, and repeatability. Based on the actual test data, the corresponding technical indicators are given. The uncertainty of indication error is analyzed in detail and the corresponding evaluation example is given. An effective evaluation method for the metrological traceability of handheld laser-induced breakdown spectrometer is given.
Research on the Application of a New Water-Cut Test Device for Oil Well in Offshore Platform
LIANG Enwu, LI Fenghui, WANG Yuejie, ZHANG Jiwei, ZHENG Zhongliang, GAO Yunfeng, WANG Bin, LI Zhipeng
2022, 66(8): 61-66. doi: 10.12338/j.issn.2096-9015.2021.0222
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A new type of water-cut test device with offline sampling detection function for high water-cut oil wells was developed and applied in an offshore oil field. The results of the filed study on the offshore platform showed that for the high water-cut oil wells with water-cut larger than 90%, four layers of composite oil-water separation membrane should be used for water content determination, and the determination time should be within 15 min so that the percentage change of the determination result is within ±1.0% compared with the centrifugal water content data, and the error of the determination result is within ±0.2% compared with the water content data of professional institutions, and the determination result is closer to the field production data. The operation of new water-cut test device is intelligent and easy to operate. The device reduced the impact of well fluid fluctuations using sampling volume amplification, realized the rapid oil-water separation using a complex oil-water separation membrane and vacuum pump, and prevented the adhesion loss of crude oil in the process of produced fluid transfer using a detachable sampling tank, prevented the adhesion of crude oil using superhydrophobic oil coating, avoided the error of volume reading using the weighing module so that the measurement of water content was more accurate and faster. The new water-cut test device meets the field demand for more accurate, faster, and more convenient determination of water content in high water-cut wells, which is conducive to the later adjustment of oil well production fluid optimization and lateral drilling decision.
Analysis on Influencing Factors of Indication Error of Fuel Dispensers
MA Jun, LIAO Hongyi, CAO Xianke, YANG Chao
2022, 66(8): 67-71, 56. doi: 10.12338/j.issn.2096-9015.2020.0316
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The influencing factors of the indication error of fuel dispensers mainly come from the ambient temperature, flow rate of, standard metal gauge, and vapor recovery system. In this paper, the influence of such factors on the error of indication value of fuel dispensers are analyzed through multiple groups of comparative experiments. The results showed that the verification value of standard metal gauge is lower than the actual measurement when the gasoline temperature is lower than the ambient temperature in summer. However, the verification value of standard metal gauge is higher than the actual measurement in winter. Under the same verification conditions, the fuel nozzle has a larger indication error when refueling with a large flow than with a small flow. Different structural features of standard metal gauges will cause different degrees of volatilization of oil and gas, resulting in different indication errors when other conditions are the same. Activating the vapor recovery device will reduce the actual oil output of the fuel dispenser, and the larger the gas-liquid ratio, the larger the indication error will be.