高频电压频率附加误差线性回归修正及其不确定度分析

本文针对高频电压表频率附加误差检定中示值定度偏差问题进行了探讨和分析,提出了修正措施,并对修正数据进行不确定度评定。     

基于LabVIEW的宽频带电压表自动检定系统模拟器设计

根据宽频带电压表自动检定系统相关理论,在计算机的控制下,采用面向对象的可编程语言LabVIEW,设计了宽频带电压表自动检定系统模拟器,模拟宽频带电压表自动检定系统的工作过程,根据计量检定原理以及计量检定规程,实现了宽频带电压表电压刻度误差和频率附加误差的自动检定。系统选用目前国内外最先进的电压标准组合,建立频率范围从10Hz～1.2MHz,电压范围从（0～1100）V,分辨力1μV的低频电压标准量值和频率范围从10Hz～2GHz,电压范围从0.2～2V,测量不确定度为0.6%～1.5%的高频电压标准量值,提高了电压参数自动化测试水平。     

一种高频电压标准装置的设计

本文介绍一种高频电压标准装置的设计方案,该标准频率范围宽,电压量程范围大,测量准确度高,可以对电压表的频率附加误差进行检定、数据处理、存储和证书打印.     

高频电压表频率误差检定的商讨

高频电压表频率误差检定的商讨中国计量科学研究院周信豪高频电压表通常是指模拟式和数字式的探头型电子电压表，这类电压表由于工作频率和量程机宽，为减少检定／校准的工作量和使误差表达简练、清晰，探头型电压表一般都是采用基本误差和频率附加误差两项分别表达它的测...     

电子电压表在非定度频率条件下的误差分析及修正

一、引言基本误差和频率附加误差是电子电压表检定中的主要项目。基本误差△是指在正常条件下(此时信号源的信号频率为定度频率f_o)电子电压表的误差,频率附加误差△_f是在信号源频率为非定度频率f(其他条件不变)时,电子电压表指示值偏离正常条件下的指示值的变动量。本文介绍电子电压表的△、△_f和非定度频率下的实际误差δ_f间的关系式,以及已知△、△_f对电压表在非定度频率信号下的测量结果进行适当的修正。二、△、△_f与δ_f的关系在正常条件下,△的定义如下式:     

高频电压表自动检定系统

本文介绍了高频电压表自动检定系统 ,该系统应用计算机控制技术 ,根据热电变换原理和交直流替代方法 ,建立稳定、可靠、准确的电压标准量值 ,实现对高频电压表的自动检定、数据处理和证书打印     

数字电压表检定分压箱的方法

依照国家计量检定规程ＪＪＧ５３１－８８,直流电阻分压箱的基本误差检定可采用电压比法。通过直流标准电压源输入被检分压箱一额定电压ＶＮ,采用高精度直流数字电压表直接测量被检分压箱输出电压Ｖｘ。通过计算,得出分压系数Ｋｘ＝ＶＮＶｘ。这一方法是目前对分压箱分压系数进行检定的最便捷的方法。但是,在具体使用中,由于数字电压表输入电阻的影响,使得在测量分压箱不同输出电压时,由于输出电阻的变化,引入相当的误差,影响了测量结果。因而,这一方法实际上很少得到应用。本文将介绍一种方法,可直接采用标准直流电压源和高准确…     

传输线效应误差的消除和修正

传输线效应是一项系统误差，当传输距离已知时，如果能准确地测量出高频电压表的输入电容量，则可以对由此产生的影响进行修正从而达到降低和消除此项误差。文中提出了一种可以在所需的频率和电压值条件下，能准确地测量出高频电压表输入电容量的方法。     

一种电子电压表检定仪的研制

本介绍一种电子电压表检定仪的工作原理及设计方法，该仪器是具有定点频率、定点电压下正弦波信号输出的标准电压源，采用微差法计量原理，设计了误差电路，在误差显示器上能直读被检表偏离定点电压的误差值△，并采用集成运放简化了整机电路，因而具有准确度高，稳定性好，读数方便，使用安全可靠等特点。     

直流数字电压表的检定方法

直流数字电压表(DC—DVM)的误差检定方法很多,但从原理上一般可归纳为: 直流标准电压发生器法,直接比较法(标准数字电压表法)和直流标准仪器法。我们可以根据所具有的标准设备和被检表的级别选择最合适、最经济可靠而又简便的方法。本文仅介绍一些典型的检定方法。     

Dynamics of Frequency Estimation in the Frequency Domain

The possibility of error reduction in frequency estimations with a multipoint interpolated discrete Fourier transformation (DFT) for the Hanning window is described. An estimation of the periodic parameter by the interpolation of the DFT gives the same effect as the reduction of spectrum tails. Sidelobe suppression is obtained at the cost of widening the main lobe, and this increases noise contributions. In this paper, we try to show a tradeoff between the reduction in systematic error of the frequency estimation and the uncertainty of the estimated results due to the interpolated algorithm. The number of interpolated points depends on the noise level and on the mutual positions of the frequency components of the signal.     

Light and Buffer-Gas Frequency Shifts in the 85Rb-Maser Frequency Standard

Recently we reported the operation of an optically pumped 85Rb maser oscillating at 3.035734 GHz on the field-independent transition 52S1/2(F = 3, mF = 0 ? F = 2, mF = 0) [1]. Apart from cavity pulling, the two major sources of frequency shifts are those due to the buffer gas and the pumping light. The short-term phase stability of the standard is not appreciably affected by these shifts. The buffer-gas shift can be used to advantage to select an output frequency that is different from the ground-state hyperfine frequency.     

Characterization of Frequency Stability: Uncertainty Due to the Autocorrelation of the Frequency Fluctuations

We considered the general sampling form for the estimate of the Allan variance which is the proposed measure of frequency stability in the time domain, and we defined a variable proportional to the difference between the average fractional frequency fluctuations over the time interval ? to derive the autocorrelation coefficient of the process to which the variable belongs. Calculations of the variance of the estimated Allan variance proved that it may be convergent to its true value with infinite sample number for considered spectral densities of frequency noise. We also applied the results to estimations of frequency measurements to know the influence of the autocorrelation of the process considered. In order to obtain some direct estimates of the confidence of the estimate, distributions of the estimate were plotted by means of computer simulations, and were compared with the chi-square distribution. Those results suggested that for white-and flicker-phase noises (and white-frequency noise) we have to take into account the autocorrelation of the process, while for flicker-or random-walk-frequency noise we may regard the process as a nearly independent (and Gaussian) one.     

Frequency Stabilization of X-Band Sources for Use in Frequency Synthesis into the Infrared

An X-band source of excellent frequency stability is needed in infrared frequency multiplication of high order. Such a source has been used in frequency multiplication by a factor of 401 using a point-contact Josephson junction as a frequency multiplier and mixer. Noise data on three X-band systems are reported. Two of these systems use klystrons as the source of X-band power; the other uses a Gunn oscillator. Each of these three systems employs both cavity and injection stabilization. Injection stabilization, using a quartz-oscillator-driven multiplier chain, provides the second-to-second and minute-to-minute stability needed for the Josephson junction experiment. To our knowledge, this is the first published noise data where cavity and injection stabilization are simultaneously employed. The quality of the best system reported here is much better-both around 1 Hz from the carrier and around 50 kHz from the carrier?than the source used to multiply by a factor of 401 to 3.8 THz.     

振弦式频率读数仪频率测量值的不确定度分析

依据JJF1401-2013《振弦式频率读数仪》校准规范,对振弦式频率读数仪频率的测得值进行不确定度评定。     

Frequency Stabilization of the He-Ne Maser

A bright and monochromatic radiation from an optical maser can be used as a stable standard of wavelength, when plane mirrors in the maser are automatically controlled so that the oscillation frequency can be kept very close to the center of the atomic line. The separation of mirrors is modulated at a low frequency with a small amplitude. The fundamental-, the second-harmonic, and the third-harmonic components of the modulation frequency in the light output give correction signals for the tilt of mirrors, the power level of excitation, and the separation of mirrors. The photobeat between two independently-stabilized masers of 1.15 microns filled with Ne20 and Ne22, respectively, has been observed. The observed fluctuation of beat frequencies shows a Gaussian distribution, and no systematic frequency drift has been found. It is found that the frequency of each maser stays within several parts in 1010 and the resettability is just as good. Some difficulties with stray magnetic field from magnetostriction coils and with earth magnetic field are found. Preliminary experiments on pressure shift and its effect on the stabilized maser are discussed. The theory has been developed, and the frequency deviations as functions of the gas pressure and of the amplitude of modulation have been calculated.     

Frequency Dependent Conductivity of the Fibonacci-Chain

A real-space-renormalization method for the frequency dependent conductivity of the periodic approximants of the Fibonacci chain is developed. This scheme is based on the known 2×2 transfer matrices and additional 5×5 matrices which allow an efficient numerical evaluation of the Kubo formula. Numerical results are presented.