测量误差

According to the structural feature of modern tilting levels, the method of erecting the collimation axis to the standing axis and the principle of the setting out of slope with the tilting standing axis are expounded.

根据现代微倾水准仪的视准轴可以调整的构造特点，阐述了使水准仪视准轴垂直于竖轴的方法，以及倾斜竖轴法放样斜坡面的原理；讨论了其误差来源、大小；对照几个行业的设计、施工及验收规范和测量规范，给出了简便可行的操作方法与有效检验手段。

The uncertainty evaluation of measuring results about indicator error of digital dial gauge 0~25 mm was analyzed in this article,those indicated that it was feasible using TWIN-CHECK1200 length measuring machine as calibration tools.

介绍了0~25 mm 数显千分表的示值误差测量结果的不确定度分析，表明了用TWIN-CHECK1200测长机进行校准的可行性。

It is a standard method for both manufacturers and users to first characterize inertial accelerometers in a 1-g field through the use of an earth-bound dividing head for the purpose of measuring its scale factor and error coefficients.

作为制造和用户共同遵循的标准方法，首先在1g重力场中通过使用分度头来获得表征加速度计的特性，达到测量它的标度因素和误差系数的目的。

In order to reduce the effect of probe errors in near-field antenna measurement, the solutions are proposed as follows: On the one hand, theoretical formula of probe-compensated is derived; on the other hand, drop-shaped probe is designed and near-zone gain, far-field patterns, axial ratio, main lobe width, input impedance, voltage standing-wave ratio, electromagnetic field and current distribution of probe are obtained through the computer simulation.

针对近场测量中的重要误差源之一&探头&的影响，本文提出解决方法：一方面用探头补偿的方法，根据洛仑兹互易定理和微波网络理论对补偿的解析式进行详细推导；另一方面用两种不同的仿真软件求解终端开口矩形波导探头的近场增益、远场方向图、轴比、主瓣宽度、输入阻抗、电压驻波比、电场分布、磁场分布、表面电流分布等特性参数，可实现探头增益的修正。

In order to obtain a correct height distribution of a measured object using the conventional Fourier transform profilometry, the connecting line between the exit pupil of the projecting system and entrance pupil of the imaging device must parallel to the reference plane and in the same horizontal.

在传统傅里叶变换轮廓术三维面型测量中，为了准确得到被测物体的高度分布，必需保证投影仪出射光瞳和摄像机入射光瞳的连线与参考面平行并且在同一水平面，否则存在较大的误差。

The plasma ignition threshold of metal is got through experimental and numerical study. The vapour and plasma ignition times of the target are got based on the equation of heat conduction and cascade model. We suppose that the plasma is ignited when generations of new electrons are born in vapour generation time. The influence of temperature on the thermodynamics and optics parameters of material also have been considered in the model. The resulting theory has good agreement with the experiment and overseas report. A blade method to measure the laser spot is given in this paper with validation and error analysis. The plasma threshold of metals in atmosphere and water ambients both are diagnosed with the light deflection and piezoelectric transducer. A Q-switched pulsed Nd:YAG laser operating at infrared (1064nm), visible(532nm) and ultraviolet (355nm) wavelengths has been used. Al、Fe、Cu are used as targets and get a similar results with both method. Theoretical and experimental analyses are applied on the influence of wavelength on the threshold have been done, both of which have shown that the plasma threshold of metals decrease as the laser wavelength increases; The plasma threshold of metals are higher in water than in air and the pressure of the shock wave in water is five times higher than in air .

从热传导方程和雪崩电离机制出发，假设当电子增值210倍时，考虑了温度对材料热力学和光学参数的影响时，得到了气化和等离子体点燃的时间，利用该模型进行计算得到的结果与国内外报道及自行通过实验测得的阈值基本一致；提出了利用刀刃法测量激光光斑面积的方法，并通过实验进行了验证和误差分析；利用光偏转装置和压电换能器分别对空气和水中金属等离子体点燃阈值进行了实验诊断，激光器均为调Q－YAG激光器（波长1064nm，532nm，355nm，脉宽10ns），靶材分别为Al、Fe和Cu，两种测试方法得到的等离子体点燃阈值基本一致；本文从实验和理论计算两个方面讨论了波长对等离子体点燃阈值的影响，均得到了等离子体点燃阈值随著波长的增加而减小的结论；对空气中和水中不同环境下金属等离子体的点燃阈值进行了比较研究，得到了金属在水中的等离子体点燃阈值比空气中的大，且水中产生的冲击波的压强是空气中的5倍左右的结论。

The roundness tester is a highly precision instrument that is wildly used to measure the rotary work piece in mechanical industry. The aged roundness tester was astricted by the technique condition of that time, so its way of measurement is not at all advanced. Because these roundness testers have been used for a long time, they have a highly failure rate and their accuracy can not be insured.

圆度仪是机械工业中应用最广泛的检测回转体零件圆度误差的高精度仪器，由于老式的圆度仪受当时技术条件的限制，评定方法落后，再加上这些圆度仪的使用时间较长，使用时仪器的故障率一般都较高，测量精度也不能保证。

Therefore, it is suggested through present research that the chamfered testpiece is used and larger initial width of cut is adopted during chatter test in order that the experimental results would indicate the real dynamic behavior of machining system.

实验证明了初始切宽和试件倒角对稳定性阈限的影响，揭示出至今仍为国际上普遍采用的变切宽切削法的重要误差，为提高测量数据的一致性和完善机床动特性试验规范提供了理论和事实依据。

The design paramters can be used to measure various very well,and the calculation error and design complexing are reduced.

利用该设计能够很好地测量各项电力参量，极大地减小了计算上的误差和设计复杂性。

Base on the analysis of the grating linear displacement measurement theory,t he measure errors especially the subdivision error of the grating scale,this paper focuses on the theory of switch and merge of dual grating scales'signals,builds the design criteria of high speed high precision displacement measurement by using dual grating sales,designs the switch picking reference with high precision and fast switch and merge method,analyses the errors brought in by switch and merge of the duals grating scales.

针对光栅尺的电子细分信号具有细分误差的特性，本文提出了对莫尔条纹信号不细分的方法以提高双光栅尺信号切换合成值的精度。经过对双光栅计数切换基准、切换与合成特征和规律的探讨，本文设计了实现双光栅尺双重测量、计数值切换合成法的硬件电路，主要通过可编程芯片FPGA，设计了双光栅尺信号处理的各电路模块，如双光栅尺信号四倍频辨向模块、速度判断模块、切换模块、计数值合成处理模块。

Singer Leona Lewis and former Led Zeppelin guitarist Jimmy Page emerged as the bus transformed into a grass-covered carnival float, and the pair combined for a rendition of "Whole Lotta Love".

歌手leona刘易斯和前率领的飞艇的吉他手吉米页出现巴士转化为基层所涵盖的嘉年华花车，和一双合并为一移交&整个lotta爱&。

This is Kate, and that's Erin.

这是凯特，那个是爱朗。