Evaluation of the calibration factors of neutron dose rate meters in a 241Am–Be neutron field

Calibrations were performed for three types of neutron ambient dose equivalent rate meters, i.e., Aloka TPS-451C (Hitachi), KSAR1U.06 (Baltic Scientific Instruments), and Model 12-4 (Ludlum), using a standard field of a 241Am–Be source. The measured total neutron ambient dose equivalent rates, H*(10)' tot, were analyzed to obtain the direct neutron ambient dose equivalent rates, H*(10)' dir, using the ISO 8529-2-recommended generalized- fit method, semiempirical fit method, and reducedfitting method (RFM) fit methods. The calibration factor (CF), defined as the ratio between the conventional true value of the neutron ambient dose equivalent rates in a free field, H*(10)' FF, and H*(10)' dir, was evaluated as one of the important characteristics of the neutron meters in the present work. The fitting results show that the H*(10)' dir values of the meters are in good agreement within the theoretical data within 4%. The averaged CFs of the three neutron meters were evaluated as 0:99 ± 0:01, 1:00 ± 0.03;and 0:99 ± 0:08, respectively. The largest standard uncertainty of these values was determined to be approximately 18.47%(k =1). The standard uncertainty of the CFs obtained using the RFM method was less than 4.23%(k=1), which is the smallest uncertainty among the three methods.

Calibration of a neutron dose rate meter in various neutron standard fields

This paper presents the calibration of a neutron dose rate meter and the evaluation of its calibration factors(CFs)in several neutron standard fields(i.e.,two standard fields with bare sources of252Cf and241Am-Be,and five simulated workplace fields with241Am-Be moderated sources).The calibration in standard fields with bare sources was conducted by following the recommendations of the ISO 8529 standard.The measured total neutron ambient dose equivalent rates,denoted as H*(10)tot,were analyzed to obtain direct components,denoted as H*(10)dir,using a reduced fitting method.The CF was then calculated as the ratio between the conventional true value of the neutron ambient dose equivalent rate in a free field,denoted as H*(10)FF,and the value of H*(10)dir.In contrast,in the simulated workplace neutron fields,the calibration of the neutron dose rate meter was conducted by following the ISO 12789 standard.The CF was calculated as the ratio between the values of H*(10)totmeasured by a standard instrument(i.e.,Bonner sphere spectrometer)and the neutron dose rate meter.The CF values were obtained in the range of 0.88–1.0.The standard uncertainties(k=1)of the CFs were determined to be in the range of approximately 6.6–13.1%.

Functional Confirmation Using a Medical X-Ray System of a Semiconductor Survey Meter

In recent years, semiconductor survey meters have been developed and are in increasing demand worldwide. This study determined if it is possible to use the X-ray system installed in each medical facility to calculate the time constant of a semiconductor survey meter and confirm the meter’s function. An additional filter was attached to the medical X-ray system to satisfy the standards of N-60 to N-120, more copper plates were added as needed, and the first and second half-value layers were calculated to enable comparisons of the facility’s X-ray system quality with the N-60 to N-120 quality values. Next, we used a medical X-ray system to measure the leakage dose and calculate the time constant of the survey meter. The functionality of the meter was then checked and compared with the energy characteristics of the meter. The experimental results showed that it was possible to use a medical X-ray system to reproduce the N-60 to N-120 radiation quality values and to calculate the time constant from the measured results, assuming actual leakage dosimetry for that radiation quality. We also found that the calibration factor was equivalent to that of the energy characteristics of the survey meter.

Design of New Long-Distance Intelligent Watt-Hour Meter

The design scheme for a new kind of long-distance intelligent watt-hour meter is presented. In the system, the control computer communicates with the bank＇s host computer by the X. 25 network; the built-in embeded secure access module （ESAM） can verify data by commutation with the intelligent nodes that enhance the security of the data. IC TSS721 is adopted to collect data remotely, and the CPU IC card is used to ensure the the bargaining security and reliability. In addition, the software of the system is introduced.

New Change of Technical Indicators System of Watt-Hour Meters

There is an imperfection in the accuracy indicators system and the technical parameters system in IEC standards 62053-21 implemented for watt-hour meters currently. This article quoted some parts of OIML MI-003 and R46 contents to provide a reference of the integrity comparison between the accuracy system and technical parameter system. The comparison result shows that the watt-hour meter accuracy technical indicators system of OIML R46 is more integrated. First reason is that it determines all the accuracy （basic error） defining rules just by using the technical parameter I efficiently; secondly, it can solve the contradiction that no error regulation of the range from starting current to minimum current in the process of providing, handing over and checking watt-hour meter products＇ qualities efficiently. Please pay close attention to the R46 official version which will be released soon, as it is still in the Committee Draft （CD6） stage currently.

单点式应变量校准器电路设计方案分析

校准器输出电路是应变量校准器的最核心技术。本文介绍了两种常规的单点式应变量校准器电路设计方案,并通过理论计算和测试试验对其优缺点及可行性进行分析,提出最优方案。

油莎豆种子籽粒离散元仿真参数标定与试验

为了解决新型油料作物油莎豆排种器设计过程中种子物理参数不清及仿真参数与实际差异较大,造成模拟试验不准确,制约油莎豆排种器的发展的问题,测定了油莎豆种子的几何参数、弹性模量、泊松比、摩擦因数、碰撞恢复系数和休止角。以截面圆跳动法测出油莎豆种子精确外形轮廓并建立仿真颗粒模型,通过离散元仿真参数标定得出油莎豆种间静摩擦系数为0.662,油莎豆种间滚动摩擦因数为0.024。通过休止角试验验证,得到误差为1.61%,较标定前降低92.9%。通过排种仿真试验、排种器试验台试验和播种田间试验验证,得到仿真重播指数相对误差为3.79%、4.64%,漏播指数相对误差为6.81%、8.64%。由此表明,油莎豆仿真参数标定值可靠,可为油莎豆单粒精播排种器设计优化提供参考。

月球直射辐照度仪同光轴装调及传递定标

采用激光水平仪与平面反射镜相结合的方式,在实验室模拟月球对追踪相机与探测镜头进行同光轴装调,避免未同光轴导致测试不到信号或者信号太小造成数据不准确的问题,实验结果显示实验室同光轴装调误差在±0.03°以内。为保证仪器定标系数的准确性,采用已溯源于国家计量基准的标准灯传递定标微光灯的方式,利用激光测距仪与激光水平仪、平面反射镜相结合的方式保证传递定标精度,解决了直接使用标准灯定标带来的探测器非线性响应误差和长定标距离误差的难题。为地基对月观测仪器建立高精度的月球辐射模型提供了一种思路与解决方法。

基于物联网的流量仪表智能标定系统设计

针对流量仪表因采用手工或半自动方式标定所造成的费时、低效等问题,设计了基于物联网的流量仪表智能标定系统。在物联网边缘通过数字化感知、边缘计算、数据网关,实现数据采集和传输,满足了各种标定设备的数据互联互通。根据流量仪表标定过程的特殊性,在云端建立了基于规则的流量仪表标定专家系统。通过数据共享、数据可视化等数字化、智能化的系统设计,模拟人类标定专家的思维过程。运用知识进行推理,根据不同的流量仪表产品,及时给出满意的标定解决方案。该方案赋能流量仪表的智能标定过程,实现了标定生产过程的全自动化。该设计使标定周期由原来的120min缩短到40min,提升了流量计生产装备智能化程度,提高了生产效益。

基于台区电能量分层级解耦的电能表远程在线校准

针对电能表元件稳定性较差的问题,提出基于台区电能量分层级解耦的电能表远程在线校准方法。根据台区电能量分层级精准解耦原则,设置典型分层端口结构,求解微分解耦数据方程,实现对电能系数的计量处理。分别从AD转换器量化误差、数值求积截断误差、同步误差三个角度着手,分析校准参量的取值结果,完成远程在线校准设计。实验结果表明:采用所提方法的总线电能表示数、支线电能表示数与理想示数之间的差值水平均能得到较好控制,与三轴同步校准方法相比,更符合维持电能表示数稳定性的实际应用需求。

基于远程非车载充电机的现场校准方法研究

为了提高非车载充电机现场校准能力、改善现有技术中校验效率滞后等问题,设计了一种基于远程非车载充电机的现场校准方法。该方法通过CS5464非车载电机电能计量芯片实现非车载充电机电能计量与检测控制。在检测控制时,设计电压、电流计量电路检测等。在电能量计算时,通过MSP430FG4619核心微控制单元(MCU)芯片实现数据信息,如电压和电流的幅值、波形、频率和相位等的计算与控制。这些数据信息多角度、多方面地呈现非车载充电机工作参数信息。通过这些数据信息,可以全面反映现场校准情况、提高非车载充电机现场校准精度。通过模板校对算法,可以实现高精度非车载充电机现场校准核对,提高现场计量与核对能力。试验结果表明,该方法误差低。该方法为下一步技术研究提供新思路。

测汞仪自动化进样系统

采用自主研发的软件控制精密注射泵,并结合化学还原汞标准溶液方法,可解决目前台站监测设备测汞仪溯源困难的问题。对比分析了手动操作和自主设计自动化进样系统在测汞仪标校过程中的测试结果。通过线性曲线和重复性试验,表明自动化进样与手动操作测量都体现出极好的线性度和重复性。自动化装置和人工操作判定系数R2为0.997和0.996,重复性分别为1.8%和2.2%,表明了自动化装置测试结果比手动操作精度更高。自动化进样系统操作起来更简便、易实行,降低了工作人员的操作强度,不仅提高了工作效率,减少因操作时间过长造成的汞标准物质失效,还可避免汞源对人体的直接危害。

应用FMEA法加强油田压力表计量检定流程的节点控制

压力表作为油田生产中的重要仪器仪表,其计量检定也是确保压力表正常工作的主要手段。通过全面梳理压力表的计量检定流程,运用FMEA法来分析压力表失效模式及失效后产生的效应,并通过调查问卷的形式得到失效产生的风险系数,最终形成对检定流程节点的控制措施,期以对流程的初始节点至结束点的每一个节点,都能得到切实有效的控制,有效地减少压力表可能产生的失效,将失效影响降到最低。

光功率计功率校准能力扩展与自动校准系统的实现

光功率计是光通信网络中用于测量光功率的仪器。为了保证光功率计测量结果准确,必须对光功率计进行校准。现有计量检定规程适用于-80~27 dBm范围内光功率参数的检定和校准,为了满足大于27 dBm功率的校准并提高光功率计的校准效率,设计了一套光功率自动校准系统,并将光功率参数的校准能力扩展至34dBm。介绍了该系统的硬件组成、软件的设计思路和实现方法,并给出了不确定度评定结果。经过与中国计量科学研究院(NIM)的校准结果比较,该方法在提高校准效率的同时保证了校准结果的准确可靠。

基于电能计量的中央空调冷量分摊方法

在国家“双碳”重大战略驱动下,中央空调系统逐渐成为助力国家节能减排的重要担当。为充分调动中央空调用户的节能积极性,提高中央空调分户计费精确性,该文在分析风机盘管供冷量与耗电量关系的基础上,提出了一种基于电能计量的中央空调分户冷量分摊方法。通过仿真比较得出,该方法在低投资情况下有效地提高了中央空调分户计量冷量分摊的精度,保证了空调分户计费的公平性,更好地促进国家中央空调分户计量任务的推广。

基于云服务器的大空间高温设备远程校准系统设计

针对高温设备内的有效加热区温度校准问题,使用热电偶和标准表对其均匀性进行多点测量,并根据空间大小自由布置测温点。标准器温度采集选用六位半高精度数字表,将温度数据传输至工控触摸屏前端观测,然后将现场数据传输至云服务器进行后续处理。同时,采用云服务器或手机终端进行远程操控,克服高温环境对人体的危害,且数据结果通过云端自动进行,极大地提高了校准效率。

Novel attitude determination method by integration of electronic level meter,INS,and low-cost turntable for level attitude evaluation and calibration of INS

Attitude references are greatly needed for the evaluation and calibration of Inertial Navigation Systems(INSs),which are widely used in gravimeter,marine,and aeronautical navigation.High-accuracy turntable,INS,and Global Navigation Satellite System have been utilized to verify the performance of relatively low-accuracy INS.The accuracy requirement of the attitude reference continuously increases with the rapid improvement of inertial sensors and navigation algorithms.However,the cost of attitude determination system increases rapidly with the increase of attitude accuracy requirement.To solve this limitation,the integration of level meter,INS,and low-cost turntable is proposed to provide level attitude,such as roll and pitch.The turntable is utilized to rotate the INS.An integration model of the level meter and INS is built to estimate the level attitude and reduce the cost of the turntable.The proposed method successfully avoids the dependence on high-accuracy turntables.An observability degree analysis is conducted to improve the level atti-tude accuracy further.The simulation and turntable test results indicate that the proposed method can provide high-accuracy level attitude without high-accuracy INS or turntable and is applicable to error calibration and attitude evaluation of INS.

振实密度仪校准中的难点及校准方法研究

振实密度仪是一种专门用于测试粉末振实密度的仪器,广泛应用于制药、新能源、粉体加工等行业。多项国际国内标准中均介绍了其测定方法及要求,且相关企业的质量管理体系中均对参数校准提出了要求。其主要参数包括振动频率和位移,需进行校准,由于国内目前未有可靠的方法和设备,因此,现场校准的难题亟待解决。本文针对该问题,对校准中的难点及校准方法进行了探讨、分析及研究。

智能水表全寿命期应用管理关键问题研究

水表是供水计量的基本器具,加快智能水表应用是供水行业当前的重要任务。围绕智能水表全寿命期性能可靠及结算公平等需求,研究了智能水表应用管理中的防冻、在线校准、计量争议处置等关键问题。寒潮冰冻会导致水表损坏及计量失准,需结合地区特点提升水表抗冻性能;采用外夹式超声波流量计为标准表可有效实现大口径电子式水表的在线校准,给出了校准操作的相关建议;用户对水量计量争议关心的重点是处置程序和费用退补的公平性,介绍了水表计量争议处置和水量计量差错退补核算方法。

单侧热绝缘热流计校准装置的研制

热流计是量化热能转移的仪器。为解决非对称平面热流计、热流传感器校准的难题,基于绝对法原理,对保护板法进行改进,建立一种单侧热绝缘的热流计校准装置,由主加热器、绝热层、保护加热器、功率输出系统、温度反馈调节系统和数据采集系统组成,装置可溯源至标准功率计。在400~1 000 W/m2范围内对装置进行验证,测试结果与传统保护板法热流计校准装置标定结果基本一致。根据测试结果评估电流源偏差、背向和侧向热损失、蓄热损失、测量重复性、面积不一致、装载方式对测量结果的影响。经过实验和分析,该装置的不确定度可以达到3%以内。