【摘要】 针对基于交流采样原理的智能仪器,提出一种新的测量不确定度评定模型。以信号功率测量为例,受硬件条件以及信号频率波动的影响,无法确保同步采样,利用已有测量算法将使测量结果出现误差。将该误差视为系统效应,通过近似处理,提出简单且实用的修正算法。将测量过程中的量化噪声、信号传输中的干扰当作具有已知分布特征的随机变量,利用统计方法,并依据测量不确定度传播定律,评定了经修正算法修正后的测量结果的不确定度。这种先修正系统效应、再评定随机因素造成不确定度的模型,更符合测量过程的实际情况。物理实验和仿真计算均验证了所得结论的有效性。更多还原

【Abstract】 For measuring the power of signal by an intelligent instrument based on alternating current(AC) sampling,a new model of uncertainty evaluation is presented.With the effects of hardware and the frequency fluctuation of signal,the synchronous sampling becomes an asynchronous process.In this case,if it still adopts the algorithm on the basis of synchronous sampling,it will result in the measurement error that can be regarded as a systematic effect.A simple correction algorithm is presented by an approximate method.Assuming the quantization noise and the interference in sampling process as random variables with specific distribution characteristics,the combined uncertainty of the measurement result by the new correction algorithmis evaluated by the statistical method and the law of uncertainty propagation.The model,correcting the systematic effect firstly and then evaluating the uncertaintyof the random effects,is more accordant with the measurementpractice.The physical experiments and computer simulationsverify that the results are valid.更多还原