Table of Content

25 October 2021, Volume 41 Issue 5

Previous Issue    Next Issue

Research on Active Optical Path Control in Optical Time and Frequency Transfer through a Fiber Link

XIAO Qing-wen, YANG Hong-lei, HU Gang, ZHAO Huan, ZHANG Sheng-kang, GE Jun

2021, 41(5):  1-5.  doi:10.12060/j.issn.1000-7202.2021.05.01

Asbtract ( )   PDF (2175KB) ( )  

Related Articles | Metrics

Time and frequency transfers through fiber links have advantages of high stability,high signal-to-noise ratio and anti-jamming capacity over the other techniques.As the path length increases,optical phase jitter introduced by fiber link dramatically increases.This phenomenon is the main limitation of the performance.Here we demonstrate an active optical path control system in a long fiber link.In this system,a fiber-loop optical-microwave phase detector is integrated to obtain the phase error between return optical femtosecond pulses from remote site and local clock reference.It avoids the intense phase noise caused by direct photoelectric detection,therefore improves the sensitivity of phase detection.Meanwhile,an optical fiber stretcher and motorized optical delay line are utilized and automatically controlled in real-time.The home-built active optical path control system is experimentally tested in a 11 km optical fiber link.The time deviations are 1.55 fs/s and 0.12 fs/1 000s,respectively.Correspondingly,the frequency stabilities are 3.06×10^-15/s and 1.99×10^-19/1 000s,respectively.

Design of a Standard Device for Vector Gradient Magnetometer

ZHAI Jing-jing, LI Xiang, MENG Cheng

2021, 41(5):  6-10.  doi:10.12060/j.issn.1000-7202.2021.05.02

Asbtract ( )   PDF (1706KB) ( )  

Related Articles | Metrics

As an important means of weak magnetic field detection,magnetometers have been widely used in fields such as national defense,military industry,geophysical detection,and so on.At present,underwater magnetic surveys and aerial magnetic surveys use gradient magnetic fields to judge and determine abnormal points.Positioning,therefore,the accuracy and sensitivity of gradient magnetic field measurement directly affect the accuracy of the result.This article introduces a combined vector gradient magnetic field standard device,which reproduces the standard gradient magnetic field and uniform magnetic field,and can calibrate the accuracy of the gradient magnetometer.The device is mainly composed of a uniform magnetic field reproduction system and a two-dimensional gradient magnetic field reproduction system,which can superimpose a gradient magnetic field on the basis of a uniform background magnetic field with a controllable direction and an adjustable size to fully reproduce the background of the gradient magnetometer in the working process magnetic field.The uniform background magnetic field ranges from 20 μT to 100 μT,and the gradient magnetic field ranges from 10 μT/m to 100 μT/m,The measurement uncertainty is 1.2×10^-3B_r+1.4 nT/m (k=2).

Analysis and Solution of Abnormal State of Verification Device of Three-phase Electric Energy Meter

YANG Tu-qiang

2021, 41(5):  11-15.  doi:10.12060/j.issn.1000-7202.2021.05.03

Asbtract ( )   PDF (770KB) ( )  

Related Articles | Metrics

The verification device of three-phase electric energy meter is widely used in legal metrological verification institutions and authorized metrological technical institutions.In the process of using three-phase electric energy meter verification device to carry out watt hour meter verification,abnormal phenomena such as software failure response,current I protection alarm,overload alarm,open circuit alarm,short circuit alarm occur from time to time.This paper analyzes and studies these abnormal phenomena combined with specific examples,summarizes the fault manifestations of verification device under different abnormal states,and puts forward scientific solutions,It is of great practical significance to guide the verification personnel to find out the root cause of the fault and eliminate it in the first time with detailed case.At the same time,energy meter verification device manufacturers improve the production process according to this research,which is helpful to improve the product quality and reduce the failure rate.

Development of Control System for 1mN～10N Force Standard Device

NI Jin-quan, LI Tao, HU Gang, JIANG Ji-le, NI Xi-dong

2021, 41(5):  16-21.  doi:10.12060/j.issn.1000-7202.2021.05.04

Asbtract ( )   PDF (1184KB) ( )  

Related Articles | Metrics

Based on the design and development of the control system of 1mN~10N force standard device,this paper introduces the classification,principle,structure and composition of force standard device.The device adopts the domestic first design structure,reduces the uncertainty of force value reproduction,improves the measurement performance of force value standard device,provides a new means of static weight micro force value transmission for force value measurement department,and solves the problem of value traceability of high accuracy micro force sensor.The key points of control system design and intelligent monitoring system design mentioned in this paper provide technical guidance for the measurement and testing personnel of force value specialty to study the design of micro force value transmission standard device,so as to promote the in-depth development of the measurement guarantee of high accuracy micro force value throughout the country.Measurement range of the device:1mN~0.5N,uncertainty of force value 1.0×10^-4(k=2);Measurement range:0.5N~10N,force value uncertainty 4.0×10^-5(k=2).

Analysis of Electromagnetic Amplitude and Phase Characteristics at Different Positions in the Quiet Zone of a Large Compact Field

MA Yong-guang, ZHANG Yan-zhao

2021, 41(5):  22-26.  doi:10.12060/j.issn.1000-7202.2021.05.05

Asbtract ( )   PDF (3796KB) ( )  

Related Articles | Metrics

The large-scale compact field is installed in a microwave anechoic chamber specially designed for the laying plan of absorbing materials.Due to the characteristics of the feed pattern of the compact field,the center position of the feed phase,the processing accuracy of the reflecting surface,the shape and size of the reflecting surface tooth,the reflecting surface segmented splicing and splicing accuracy with the side tooth,the relative geometric relationship between the feed and the reflecting surface ,the position relationship of the quiet zone relative to the reflecting surface and many other factors,the electromagnetic amplitude and phase distribution characteristics of the quiet zone of the large-scale compact field vary greatly with the working frequency and spatial position.This paper uses a large-scale compact field with a quiet zone size of 5m×5m×5m,and analyzes the electromagnetic amplitude and phase distribution characteristics of the vertical section in the vertical direction of the incoming wave at three different positions in the front,middle and back of the quiet zone in the working frequency band (0.5~40)GHz.The test results were analyzed in detail for the electromagnetic amplitude and phase difference of the same cross section at different operating frequencies and the electromagnetic amplitude and phase difference at different cross-sectional positions in the quiet zone.

Research on Availability Prediction based on GBAS

HAN Ming, ZHANG Jian-jun, LV Zi-peng, DENG Qi, LIU Wen-liang

2021, 41(5):  27-31.  doi:10.12060/j.issn.1000-7202.2021.05.06

Asbtract ( )   PDF (1100KB) ( )  

Related Articles | Metrics

GBAS availability prediction is a prediction of GBAS service status and satellite constellation statue in the whole approach and guidance process of Ground Based Augmentation System(GBAS).It is an important monitoring measure for civil aviation GBAS application to assist tower monitoring personnel in monitoring.In order to ensure the reliability and safety of GBAS airborne users’ precision approach and guidance landing in terminal area,this paper proposes a usability prediction method based on GBAS ground reference position.This method predicts the status of future satellite constellation through ephemeris or almanac,relevant peaks of satellite signal,GBAS message information,and then completes the prediction of GBAS service status,So that the system can send the forecast alarm to the tower monitoring personnel in time,adjust the GBAS approach procedure,and then achieve the purpose of availability monitoring,and improve the integrity and availability of the system.

Research on the Cryocool System for Liquid Helium Free Quantum Voltage Device

JIAO Yu-min, KANG Yan, ZHU Zhu

2021, 41(5):  32-35.  doi:10.12060/j.issn.1000-7202.2021.05.07

Asbtract ( )   PDF (2029KB) ( )  

Related Articles | Metrics

The traditional quantum voltage standard device,liquid helium is used to provide 4.2K low temperature environment,but under background of tight supply of global liquid helium resources and more expansive,it is of practical signification to study the refrigeration free helium technology suitable for quantum voltage standard device,reduce the cost of standard operation and maintenance,and expand the use range of standard.However,the change of cryocool system need solve two problems:one is that the cooling capacity provided by the cryocool system must exceed the operation demand of superconducting array,and the other is to keep the temperature fluctuation during the operation of the chip within the allowable range.The paper introduces a cryocool system can solve the problems above.According to the technical requirements of superconducting chip,the operating temperature is less than 4.2K,the cooling power is more than 1W,and the temperature fluctuation is 20mK.

Research on Measurement of Sub Pixel Luminance of Micro Display

WANG Shao-shui, RUAN Yu-jiao, FEI Feng, ZHAO Fai-cai, LV Zi-jing

2021, 41(5):  36-40.  doi:10.12060/j.issn.1000-7202.2021.05.08

Asbtract ( )   PDF (3000KB) ( )  

Related Articles | Metrics

In order to meet the requirements of the micro display for the measurement of sub pixel luminance and chromaticity parameters,this paper introduces the micro-objective into the imaging luminance meter scheme.A set of microscopic imaging luminance meter is designed and developed by using high resolution camera,XYZ color filter,micro-objective lens,and the micro level target is tested.The mobile phone screen,micro display and standard reticle are tested.The experimental results show that the luminance and chromaticity of samples with size less than one micron can be measured,when 31 megapixel resolution camera and 50 times micro lens are used.The luminance test error after calibration is less than 1%，and the uncertainty is 2.5%(k=2).

Research on Object Detection Method of Millimeter Wave Image based on YOLOv5

ZHANG Ge-fei, LI Chun-yu, LIU Jin-kun, QU Yin-xuan

2021, 41(5):  41-45.  doi:10.12060/j.issn.1000-7202.2021.05.094

Asbtract ( )   PDF (1474KB) ( )  

Related Articles | Metrics

Millimeter wave imaging technology is an emerging direction in the field of security inspection.Researching object detection algorithms that meet this application scenario and improving the corresponding detection speed and detection accuracy have high application significance and value.This paper proposes a real-time object detection algorithm based on the YOLOv5 deep learning model to detect contraband hidden by security personnel.The method uses the GIOU_Loss loss function to improve the ability to measure the intersection of the detection frames.In addition,the network structure is optimized and the improvement and the addition of the millimeter wave data enhancement preprocessing function to accelerate the convergence,thus forming a deep neural network for millimeter wave images for item detection to improve the object detection effect.Experimental results show that this method can effectively detect dangerous goods in millimeter-wave images,and has the advantages of automatic identification and real-time detection.

Comparative Study on the Range Method to Measure Energy of Low Energy Electron Accelerator

CHEN Yi-zhen, XIA Wen, ZHANG Wei-dong, LUO Rui, LIN Min, CHEN Ke-sheng

2021, 41(5):  46-49.  doi:10.12060/j.issn.1000-7202.2021.05.10

Asbtract ( )   PDF (1629KB) ( )  

Related Articles | Metrics

In order to accurately,quickly and conveniently measure the energy of low-energy electron accelerators for radiation processing,the range method is used to measure the electron beam energy in this work.A wedge measurement device and a stack measurement device were designed and manufactured made of polystyrene material.Combined with the radiochromic film dosimetry system,these two different types of devices were used to simultaneously measure the energy of the accelerator electron beam with a nominal energy of 0.65MeV.The results show that the designed wedge measurement device can measure the energy of the electron beam as low as 0.65MeV.Compared with the stacked energy measurement method,the wedge measurement method is more convenient,more efficient,and the uncertainty introduced is smaller.In practice,when measuring the energy of low-energy electron beam above 0.65MeV with the range method,a wedge measurement device is recommended to measure the electron beam energy.

Study on the Establishment and Characteristics of Narrow-series Radiation Quality of Mobile X-ray Irradiation Device

WEI Kai-di, GAO Fei, XU Yang, WANG Fei-fei, LIN Min, NI Ning

2021, 41(5):  50-56.  doi:10.12060/j.issn.1000-7202.2021.05.11

Asbtract ( )   PDF (1479KB) ( )  

Related Articles | Metrics

Based on the mobile X-ray irradiation device developed by the Radiation Metrology and Measurement Division of the Chinese Institute of Atomic Energy,the measurement research of tube current linearity,inherent filtering and additional filtering is carried out.The movable X-ray irradiation device needs to be moved frequently during use.In consideration of increasing the mechanical strength,a 4mm aluminum sheet is reserved in front of the beryllium window to protect the beryllium window.The MCNP program is used to simulate the X-ray emission of the Al sheet in different positions.The fluence spectrum of the beam is compared with the standard spectrum to verify the feasibility of the method.The experimental results show that at the same energy,the ionization current of the ionization chamber has a linear relationship with the dose rate of the X-ray radiation field;the relative deviation of the simulation value of the average X-ray energy from the recommended value of ISO 4037 is within 3%;the supervised ionization is obtained by linear interpolation The inherent filtration under room conditions is 4.01mmAl;the relative deviation of the measured value of the first half-value layer corresponding to each radiation quality and the standard recommended value is within 5%.This work can be used for on-site calibration of portable X-ray irradiation devices.

Design and Development of a Calibration Source for Ground-based Microwave Radiometer

CHENG Jun-jie, CAO Yue, SUN Xiao-ning, YANG Han-xu, ZHAI Hong

2021, 41(5):  57-60.  doi:10.12060/j.issn.1000-7202.2021.05.12

Asbtract ( )   PDF (1797KB) ( )  

Related Articles | Metrics

Microwave radiometer calibration technology is a prerequisite for quantitative remote sensing applications.According to the calibration requirements of microwave radiometer for atmospheric exploration,a calibration source group composed of cold calibration source,normal temperature calibration source and thermal calibration source is designed and developed to complete the calibration work of radiometer observation brightness temperature range.In this paper,the working principle of radiometer calibration source is introduced firstly,then electromagnetic simulation and test results of emissivity of radiator are given,the results show that the emissivity of radiator is about 0.999 9.Finally,the temperature control mode,temperature control structure and temperature test results of calibration source are introduced,the test results show that the temperature uniformity of calibration source group is better than 0.2K and the temperature stability is better than 0.023K This device high precision and reliability and has been used in the daily calibration of ground-based radiometer.

Development of Integrated Test System for Coordinator

GAO Yuan, CHANG Hui-juan, WANG Xin-da

2021, 41(5):  61-66.  doi:10.12060/j.issn.1000-7202.2021.05.13

Asbtract ( )   PDF (2266KB) ( )  

Related Articles | Metrics

Aiming at the calibration and test requirements of the coordinator in production,debugging and inspection,an integrated test system for coordinator is introduced in this paper.The test system is equipped with a high-precision desktop turntable and a marble stable platform.The positioning accuracy of the turntable can reach ±0.0005°,which can accurately and quickly simulate the flight attitude of the aircraft such as emergency maneuvers.The test system controls the movement of the coordinator through the electrical control and data acquisition system,and collects,analyzes and stores various indicator information such as the φ-angle coil output signal during the work of the marker in real time.At the same time,the system also has the automatic test function,which can automatically complete 8 test tasks such as the gyroscope tracking field test of the marker according to the selected test items.At present,the test system has been successfully applied to the indicator checking and performance evaluation of the coordinator,which improves the production test efficiency of the coordinator.

Research on Measurement of β Ray Absorbed Dose Rate under Nonuniform Conditions

DONG Shi-bin, WEI Ke-xin, SONG Ming-zhe, TENG Zhong-bin, LIU Chuan-feng, WANG Hong-yu

2021, 41(5):  67-74.  doi:10.12060/j.issn.1000-7202.2021.05.14

Asbtract ( )   PDF (1661KB) ( )  

Related Articles | Metrics

According to the β-ray reference radiation fields generated by ⁹⁰Sr-⁹⁰Y and ⁸⁵Kr sources,the measure-ment of tissue absorbed dose rate under non-uniform conditions.The effective collection area of 7.25 cm² was measured with the capacitance method.The relative deviation of the effective collection area from the geometric nominal value is 0.185 cm².And then the correction factors were measured,including the correction factor for the variations in the attenuation and scattering of beta particles between the source and the collecting volume due to variations from reference conditions,k_abs,the correction factor for the variations of air density in the collecting volume from reference conditions,k_ad,the correction factor for the effect of bremsstrahlung from the beta-particle source,k_br and the correction factor for ionization collection losses due to ionic recombination,k_sat.In conclusion,the characteristic parameters of the extrapolation chamber and several correction factors for absolute measurement of the absorbed dose rate were obtained in this work.And the absorbed dose rates at different calibration distances（11 cm,20 cm,30 cm and 50 cm from the radiation source to the entrance window of the chamber) were determined.The uncertainties of tissue absorption rate measurement for ⁹⁰Sr- ⁹⁰Y and ⁸⁵Kr sources are 2.7 %（k=2) and 2.9 %（k=2),respectively.The results can provide technical supports for improving the traceability and the dissemination of the β-ray dose equivalent.

Design and Simulation of Engine Test Bench Vectorial Thrust Calibration System based on Pulsed Excitation

HUANG Xiang-hua, YANG Hai-sheng, JIANG Feng, YANG Shui-wang, SONG Zhi-qiang

2021, 41(5):  75-81.  doi:10.12060/j.issn.1000-7202.2021.05.15

Asbtract ( )   PDF (1958KB) ( )  

Related Articles | Metrics

Based on the aerospace engineering requirements for vector thrust calibration of engine test benches,a set of vector thrust calibration devices suitable for field calibration is designed.The overall scheme of the engine vector thrust calibration system is determined by comparing various schemes,the structural design of the pendulum vector thrust excitation source is carried out,and the dynamics of the excitation device is modeled and the simulated.The simulation results show that the solution can satisfy the calibration of the engine vectorial thrust,which provides a basis for further calibration work.

Research on the Countermeasures of Enhancing the Integrated Logistics Support Ability of Foreign Trade Models

WANG Hai-lin, LV Bo

2021, 41(5):  82-86.  doi:10.12060/j.issn.1000-7202.2021.05.16

Asbtract ( )   PDF (2047KB) ( )  

Related Articles | Metrics

This paper starts with the development of foreign trade industry.First of all,this paper analyzes the main problems in the Integrated Logistics Support (ILS) of foreign trade models.These problems restrict the sales of foreign product.Then,it puts forward the corresponding countermeasures for ILS work of new foreign trade models,performance projects and in-service models.With the support of support technology and support products,establish a contract support service and technical support service mechanism,and promote the transformation and upgrading of equipment support from providing foreign trade products to giving consideration to the provision of support services.These countermeasures can promote the construction of foreign trade model support service system and improve user satisfaction .Finally,it introduces two information systems include remote support system and in-service equipment support management system,which can improve the equipment support efficiency effectively.

Exploration and Suggestion on Internationalization of National Defense Industry Measurement

WEI Wei, ZHANG Bo, ZHANG Li, JIANG Xiao-yong, SONG Guo-jun

2021, 41(5):  87-91.  doi:10.12060/j.issn.1000-7202.2021.05.17

Asbtract ( )   PDF (820KB) ( )  

Related Articles | Metrics

In the new historical period,the global interconnection is accelerating,and a new round of scientific and technological revolution and industrial revolution are rising.Measurement is the basis for the development of science and technology.The development of measurement technology is related to the national economy and people’s livelihood,national security and an important symbol of national core competitiveness.National defense military industry measurement is not only the support and guarantee of national defense science,technology and industrial products,but also the firm cornerstone of promoting the healthy and sustainable development of the national economy.This paper focuses on the international development demand of national defense military metrology,and it is of great practical significance to combine the important measures of national strategy,the practical needs of equipment “going out” and the internal requirements of measurement innovation and development,and put forward relevant suggestions.

Reference of European Metrology Research Programme to the Development of China’s Microelectronic Metrology

LI Lei, ZHANG Hui, ZHANG Hong, SHA Chang-tao

2021, 41(5):  92-6.  doi:10.12060/j.issn.1000-7202.2021.05.18

Asbtract ( )   PDF (713KB) ( )  

Related Articles | Metrics

As an emerging technology,microelectronics technology is one of the cores of the world’s electronic information industry.With the rapid development of microelectronics technology,higher requirements are put forward for the development of microelectronics metrology technology in China.Since 2009,the European Union has started the European Metrology Research Program (EMRP) in the fields of nanotechnology,communications,and advanced manufacturing to ensure the political and economic advancement of the European Union.Against the background of rapid development in the information age,tracking and studying the research related to microelectronic metrology in the European Metrology Research Program,and learning from the European Union’s advanced microelectronic metrology construction experiences,have important research significance for the leap-forward development of microelectronic metrology in China.