共查询到19条相似文献,搜索用时 156 毫秒
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研究了飞机螺旋桨桨叶力矩平衡的测量方法,分析比较了天平力矩平衡测量法和传感器力矩平衡测量法两种测量方法,给出了桨叶力矩平衡测量的要求及两种测量方法的原理并分析了2种方法的优缺点.重点介绍了根据天平力矩平衡测量方法研制的桨叶力矩平衡机的机构和特点,并通过试验验证了天平力矩平衡测量法的可行性. 相似文献
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一、概述1.测量依据JJG99-2006《砝码》检定规程。2.环境条件温度:22℃;相对湿度:50%。3.配套设备与计量标准器TG55型标准天平:max:5kg,d=e=10mg;F1等级标准砝码。4.测量对象标称值为5kg的M1等级砝码。5.测量方法采用单次替代称量法通过检定合格的标准天平,一边选择相同标称值的砝码作替代使天平平衡,另一边对被测砝码与标准砝码进行比较测出两砝码的质量差,测 相似文献
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磁梯度张量是目前磁信息应用领域的研究热点,尤其在探测未爆弹(UXO)方面,具有更好的反演能力.本文提出了一种基于旋转装置的磁梯度张量测量方法,基于该方法的测量系统包含两个单轴磁力仪和一个旋转装置,两个磁力仪在相互平行的两个平面上,它们的敏感轴共线,但方向相反,且与平面存在固定夹角.测量时,两个磁力仪饶与平面垂直的同一个轴旋转,旋转半径相同,利用磁力仪的输出可解算得到磁梯度张量.该方法可减少磁梯度张量测量系统的磁力仪数量,从而节约成本,降低系统误差.仿真结果表明,基于该方法的测量系统可有效测得磁梯度张量,且测量精度优于十字形轴向差分测量阵列. 相似文献
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基于激光多普勒效应测量转轴单截面转速的原理,通过测量双截面的转速进而求两截面的转速差。对转速差进行积分得到在扭矩作用下转轴两截面的相对扭转角,从而得到转轴扭矩,实现传动轴扭矩的非接触测量。同时,设计了实验系统并在扭矩实验平台进行了实验,实验结果表明,激光多普勒法与传统扭矩测量方法的相对误差小于0.2%,说明激光多普勒法具有较高的测量精度。 相似文献
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针对ADC型测温电桥因电路结构复杂、集成度高、非线性误差来源多样,导致现有误差修正方法效果不佳的问题,提出了一种基于误差来源分析的修正方法。根据ADC型测温电桥原理定量分析了电路中运算放大器共模抑制比、正反向电流不匹配度对非线性误差的贡献,运用RBC开展了这两个误差源的最大似然估计及修正,并对剩余残差进行了多项式拟合,实现了非线性误差修正;基于自制ADC型测温电桥及RBC对上述修正方法进行了验证,实验结果表明:所提方法修正后的最大非线性误差为-1.77×10-5,相对于传统非线性修正方法的最大非线性误差-3.57×10-5有了显著提升。 相似文献
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介绍了参考电势变压器和指零仪变压器设计原理,分析了屏蔽间泄漏对测量结果的影响;对常规两次平衡参考电势对检法进行了改进,使零平衡和段平衡测量过程中,参考电势和测差电路均可实现等电位保护;对自校准方法进行了推导,校准结果仅与段平衡和零平衡时锁相放大器测量的电压差值相关,与参考电势变压器、指零仪变压器、辅助变压器等的误差无关,屏蔽间泄漏的影响也得到消除。对1kV感应分压器进行了校准实验,并对校准结果进行了测量不确定度分析,其相对扩展不确定度的评估结果为5.4×10-8(k=2)。 相似文献
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能量天平法已在中国计量科学研究院开展了几年的研究。研究的目的与功率天平法是一致的,即通过测量普朗克常数来建立质量量子基准,但具体方法不同。2010年以来该项研究取得一定进展。例如对于直流互感量测量这一关键问题,已研究出一种新的方波补偿方法,测量不确定度达到10-7量级(k=1)。还研发了一种涡流传感器,可更准确地对可动线圈定位。线圈系统的准直问题也得到进展,研制了一种油阻尼器,大大减小了由于天平基础振动和线圈加热上升气流引起的线圈抖动。这些措施改善了线圈位置及互感测量的不确定度。测量普朗克常数h的最新结果为6626104(59)×10-34J·s,综合的相对不确定度为8.9×10-6(k=1)。对所遇到的困难和进一步的改进措施也在文中进行了讨论。 相似文献
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A device for calibrating large dc instruments ranging up to 320 kA has been designed. The calibrating coil simulates the actual busbar and its turns can readily be changed to meet various required measurement ranges. The calibrating coil is arranged in the shape of a cross so that we can determine the influence of the external magnetic field. The accuracies are 6×10-6 when a differential current measuring method is adopted and 200×10-6 when a differential voltage measuring method is adopted. The stability of the power supply is 0.02% per hour. The error due to the current fluctuation is very small and thus can be neglected 相似文献
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Shi Wei Zhao Cheung N.C. Wai-Chuen Gan Zhen Gang Sun 《IEEE transactions on instrumentation and measurement》2009,58(10):3569-3575
The magnetic characteristics of a linear switched reluctance motor (LSRM) are important in its performance prediction and verification. Owing to the complicated magnetic paths, the measurement of the flux linkage for this type motor has drawn many researchers' attentions. In this paper, a new flux linkage measurement method for LSRMs is proposed to obtain the flux linkage characteristics of LSRMs using an online winding resistance estimation technique. Both the theoretical derivation and the actual implementation of the proposed method are addressed in this paper. In comparison with the search coil scheme and the static resistor scheme, experimental results confirm the validity and accuracy of this method. In short, the proposed method is simple, effective, and easy to be implemented. It is a practical solution for flux linkage measurement of LSRMs and other motors. 相似文献
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A 100000-A, high precision device of the magnetic modulation current comparator type, which can be used in industrial heavy direct current systems for online calibration and measurement, is presented. Testing of the comparator indicates that its current ratio accuracy is 5×10-5, and that measurements of voltage with a standard resistor achieve an accuracy of 5×10-4. These are slightly degraded to 3×10-4 for on-site calibration and 1×10-3 for on-site measurement. The device, which has a toroidal configuration, can be opened for each installation on a busbar, with a variation in accuracy of less than 2×10-5. Its magnetic shielding renders it insensitive to magnetic fields up to 1×10-2 Tea. Its accuracy is better by a factor of two than that of similar industrial measuring devices. The principle of operation and the characteristics of the comparator, the double shielded design, and an analysis of its errors are discussed 相似文献
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Hirvonen T.M. Vainikainen P. Lozowski A. Raisanen A.V. 《IEEE transactions on instrumentation and measurement》1996,45(4):780-786
A high-Q hemispherical open resonator is connected to an automatic network analyzer to enable precise and fast determination of the permittivity and loss tangent of low-loss dielectric materials at 100 GHz. Both scalar theory and vector theory with a frequency variation method are used to determine the dielectric properties of low-loss materials which are used in quasioptical components, for example in fusion reactor windows and tenses for millimeter-wave receivers. The uncertainty of the measurement is 0.02% to 0.04% for εr(ϵr⩾2) and 6-40×10-6 for tan δ(10-4⩽tan δ⩽10-3 ) 相似文献
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A synchronous measurement method that can be applied for the accurate determination of periodic signals is presented. The method relies on adaptation of the measurement time to the period of the measurement signal. It is based on dual-slope integration performed according to the synchronization signal (input signal). The first phase of integration is fully synchronized with the input signal. The time of the first phase is also measured. The output voltage of the integrator depends directly on the input signal and the time of the first integration phase. Measurement values are the results of arithmetic operations between the time of the second phase of integration and the measuring time (first phase). With this method, an accuracy of 0.1% can be achieved 相似文献