精密压力表示值误差测量结果的不确定度评定

文章介绍了精密压力表示值误差测量结果的不确定度评定的一般方法、步骤、内容和表示方法。     

Increasing confidence in measurements and control

This article presents a general approach to increasing the accuracy of measurements and pattern recognition. A criterion for informativeness of an ensemble of signals is derived for the general case of an arbitrary signal distribution. An algorithm for determining the values of parameters from measurement signals is based on the probabilistic distance of measured points from calibration points. Translated from Imeritel'naya Tekhnika, No. 4, pp. 14–17, April, 1996.     

Indirect measurements with a probabilistic relationship between the directly measured and indirectly measured quantities

The general task is considered of indirect measurements and the combination of them when the relation between the directly measured and indirectly determined quantities is probabilistic. __________ Translated from Izmeritel’naya Tekhnika, No. 7, pp. 17–20, July, 2006.     

Minimization of error in indirect measurements

We pose the problem of minimizing the error in indirect measurements; the solution of this problem reduces to nonlinear programming. Under certain conditions, the results we obtain make it possible to increase the accuracy of indirect measurements, to design measuring systems with controlled minimal measurement error, and to control the distribution of resources in order to minimize error.Translated from Izmeritel'naya Tekhnika, No. 12, pp. 17–19, December, 1994.     

Uncertainty in relative energy resolution measurements

We suggest a new method for the determination of the detector relative energy resolution and its uncertainty based on spline approximation of experimental spectra and a statistical bootstrapping procedure. The proposed method is applied to the spectra obtained with NaI(Tl) scintillating detectors and ¹³⁷Cs sources.

The spectrum histogram with background subtracted channel-by-channel is modeled by cubic spline approximation. The relative energy resolution (which is also known as pulse height resolution and energy resolution), defined as the full-width at half-maximum (FWHM) divided by the value of peak centroid, is calculated using the intercepts of the spline curve with the line of the half peak height. The value of the peak height is determined as the point where the value of the derivative goes to zero. The residuals, which are normalized over the square root of counts in a given bin (y-coordinate), obey the standard Gaussian distribution. The values of these residuals are randomly re-assigned to a different set of y-coordinates where a new “pseudo-experimental” data set is obtained after “de-normalization” of the old values. For this new data set a new spline approximation is found and the whole procedure is repeated several hundred times, until the standard deviation of relative energy resolution becomes stabilized. The standard deviation of relative energy resolutions calculated for each “pseudo-experimental” data set (bootstrap uncertainty) is considered to be an estimate for relative energy resolution uncertainty.

It is also shown that the relative bootstrap uncertainty is proportional to, and generally only two to three times bigger than, , which is the relative statistical count uncertainty (N_tot is the total number of counts under the peak).

The newly suggested method is also applicable to other radiation and particle detectors, not only for relative energy resolution, but also for any of the other parameters in a measured spectrum, like peak position, shape parameters, etc.     

Limit of error of measurements of a mass of oil and oil products

Recommendations for establishing measurement error limits are obtained on the basis of analysis of errors and diagnosis of indirect measurements of a mass of oil and oil products. Translated from Izmeritel'naya Tekhnika, No. 5, pp. 19–21, May, 1998.     

浊度计测量结果不确定度分析

本文介绍了用于测量悬浮于水(或其他透明液体)中的不溶性颗粒物质含量的仪器浊度计的测量原理和计量单位，并依据计量检定规程(JJG880-1994)中检定示值相对误差的方法，对示值相对误差的测量结果进行不确定度评定，具体分析了各个不确定度分量的产生，并合成标准不确定度及有效自由度。评定示值相对误差测量结果的不确定度为U95rel=3．3％。     

平面度误差粒子群算法评定的不确定度评估

形状误差智能评定采用概率化随机搜索,评定结果存在分散性,针对此问题提出一种不确定度评估方法。以平面度误差粒子群算法评定为例,根据智能评定结果概率分布特性,采用β分布统示法拟合其概率分布,并对平面度误差进行区间估计,最后选取仿真平面测量数据进行不确定度评估实验。结果表明,样本个数NS=100、截取百分位数Qp=20时,估计区间能够有效包容平面度误差值,且平均宽度较小,验证基于β分布统示法的智能评定不确定度评估可行性。     

Combined measurements with a priori information on the measured quantity distributions

Combined measurements are considered that incorporate the probability characteristics of the measured quantities. In that case, the error in the joint measurements is reduced, while the number of initial equations may be less than the number of unknown quantities. Translated from Izmeritel'naya Tekhnika, No. 11, pp. 7–8, November, 2008.     

Analysis and interpolation of a primitive error function by the results of difference measurements

Conclusions The measurement schematics of many instruments based on the difference principle of measurement can be reduced to two fundamental equivalent schematics using one or two reference bases.Amplitudes A_nu and phase angles _nu (the latter only in the case of testing with a single reference base) appear with a distorted scale in practical harmonic analyses of difference measurements. The actual values of _n and A_n are obtained by correcting A_nu and _nu with the relationships given in this article taken into consideration.The values of ordinates in the harmonic analysis should be counted from the abscissa axis determined by the least squares method.     

Determination of confidence intervals for error characteristics of measurement errors and distribution-independent measurement results

We compare two distribution-independent methods for determining confidence intervals for the characteristics of systematic and random error and for interquantile intervals of complete error, the methods compared are the bootstrap and L₀ methods. We compare the properties of computational difficulty and reliability. Both methods have approximately the same reliability, but the bootstrap methods requires 4–5 times as much work. Translated from Izmiritel'naya Tekhnika, No. 10, pp. 9–12, October, 1996.     

万能工具显微镜测量大直径的不确定度评定

万能工具显微镜(以下简称万工显)是一种几何量计量的常用仪器,它被用于测量大直径小圆弧时,应当对测量结果的不确定度范围进行评定.