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181.
脉冲电场屏蔽效能测试系统及测试方法 总被引:5,自引:0,他引:5
自主研制了一套小型脉冲电场屏蔽效能测试系统,该系统由脉冲电场发射设备和脉冲电场测试设备构成。脉冲电场发射设备的天线口面前60 cm处可产生峰值达7.5 kV/m的脉冲电场,测试设备的动态测试范围达97 dB。系统采用光纤测量设备,在测量工作中能有效抑制强电磁场干扰。采用Matlab编写自动测量及数据处理程序,实现了数据采集与处理自动化。实验测量了金属桥架、控制柜、屏蔽帐篷、导电水泥混凝土房的脉冲电场屏蔽效能,其脉冲电场峰值衰减量分别为52,64,66,30 dB。实验表明可用脉冲电场的峰值衰减量来评估屏蔽体的脉冲电场屏蔽效能。 相似文献
182.
Measurement uncertainties in the determination of 210Pb and 210Po in Reference Material IAEA-300 (Baltic Sea Sediment) were evaluated. 210Pb and 210Po were separated from the matrix using an Sr resin column. The chemical yield of 210Pb was determined gravimetrically in PbSO4 form. Precipitation was followed by beta proportional counting after 210Bi ingrowth. 210Po was determined by alpha spectrometry after its spontaneous deposition on a Cu planchet. The major source of uncertainty
was identified as the statistical counting uncertainty, which was also expected and is almost impossible to reduce without
extension of the time required for an analysis. The expanded uncertainties were determined as 7.4% and 12.2% for 210Pb and 210Po, respectively.
Received: 3 September 2002 Accepted: 3 December 2002
Acknowledgement This work was financially supported by Ministry of Education, Science and Sport, Republic of Slovenia (Project group PO-0106–0532).
Presented at CERMM-3, Central European Reference Materials and Measurements Conference: The function of reference materials
in the measurement process, May 30–June 1, 2002, Rogaška Slatina, Slovenia
Correspondence to P. Vreˇcek 相似文献
183.
In this study, we introduce outdoor sound simulation that is fully compliant with ISO 9613 yet with some complementary methods that enhance its applicability; for example, calculation of sound attenuation due to undulating terrain in octave bands, geometric divergence in the near-field of the source, and short-term wind effects. Using the method, we have carried out highway traffic noise prediction and measurement for 12 sites with representative road shapes and structures. In the prediction, the sound power level for a road segment was estimated by the method suggested in ASJ Model-1998 with experimental corrections to the overall noise level and spectrum. Comparing results between predicted and measured noise levels show good correspondence at direct, diffracted and reflected sound fields within 30m from the center of the near side lane. 相似文献
184.
One of the most important aspects in designing production systems is implementing an adequate inspection procedure to ensure the product quality. Our literature study indicates that two important questions still remain unanswered. First, most of the previous studies on inspection procedures are mainly concerned with how to evaluate and analyze the adequacy of inspection procedures during a production stage. Although the issue of the adequacy of inspection procedures at this point is clearly important, many production processes may better benefit from designing enhanced inspection procedures during an early design stage. Second, the majority of previous studies do not incorporate possible economic impacts of measurement errors when inspection procedures need to be designed. More extensive efforts in designing inspection procedures need to be investigated based on economic considerations. Two approaches, the use of guard band and the selection of inspection precision level, are simultaneously examined for designing economic inspection procedures. By incorporating these two approaches, this paper proposes an optimization scheme for economic design of inspection procedures. A numerical example along with sensitivity analysis demonstrates the applicability of the proposed model. 相似文献
185.
186.
本文分析了大口径等厚条纹型F—P干涉仪在测量中可能产生的各种误差;沦证了利用成象透镜消除其主要误差(即光线的折射误差)的原理,并提出了一种提高测量精度和定标的新方法,即干涉法和CARS光谱法的结合。 相似文献
187.
HL-1装置辐射和粒子损失功率测量 总被引:3,自引:2,他引:1
一、前言在等离子体中,由于杂质的存在,产生很强的线辐射、轫致辐射和复合辐射,电荷交换产生的中性粒子由于不受磁场约束而逃逸出等离子体。本文叙述用高增益、快响应的钽酸锂热电探测器对HL-1装置等离子体辐射和电荷交换粒子损失功率的测量。二、测量方法实验中采用了KT-3130钽酸锂(LiTaO_3)热电探测器和KTH-103前置放大器。LiTaO_3 相似文献
188.
This paper deals with improvements in the measurements of optical power by using CCD-based stabilization optics. Absolute optical power scale has been realized at discrete laser wavelengths of vertically polarized tuneable Ar+, fixed He–Ne and fixed Nd:YAG (with second harmonic) laser sources. Electrical-substitution cryogenic radiometer was operated at the helium temperature for this purpose. To make measurements on the metrological level the intensities of lasers were stabilized to better than 0.004% by using an established system. Using the highly collimated and stabilized lasers, whose beam shape and dimension were adjusted properly, leads us to measure the absolute optical powers with an uncertainty in the order of 10−4. 相似文献
189.
Realisation of an effective dual-parameter sensor employing a single fibre Bragg grating structure 总被引:1,自引:0,他引:1
A novel technology for simultaneous and independent measurement of dual parameters is proposed and experimented. The length of a single fibre Bragg grating (FBG) is divided into two parts. The temperature variation and another measurand can be measured independently and simultaneously, and the thermal effect can be erased with great ease. 相似文献
190.
Ulf Örnemark 《Accreditation and quality assurance》2004,9(1-2):44-46
ISO/IEC 17025 contains general requirements for the competence of calibration and testing laboratories, including those for the evaluation and reporting of measurement uncertainty. Some accreditation bodies have issued additional guidance documents and regulations related to uncertainty, five of which are briefly commented on here.Presented at Roche Diagnostics' Workshop on in vitro diagnostics directive. A Nordic event about the implication of traceability and uncertainty in practice, Helsinki, February 13, 2003. 相似文献