虚拟仪器测量不确定度研究

对虚拟仪器的测量不确定度进行了研究.首先分析了虚拟仪器的结构及工作原理,详细论述了其测量不确定度的来源.着重研究了测量不确定度的评定方法,特别是不确定度分量的估计和合成不确定度的计算.强调了传感器环节带来的不确定度的根本性意义,指出虚拟仪器的B类不确定度必须用标准仪器进行校验.以多次测量取均值测直流电压的实例说明了多次测量取均值会将测量精度大大提高.该方法已经在某低频电参数综合校准设备中应用,验证了其正确性.

Study on Measurement Uncertainties of Virtual Instruments

This paper studies the measurement uncertainties of virtual instruments (VI), analyzes the structure and working principle of VI, and discusses the sources of measurement uncertainties in detail. Evaluation approaches of measurement uncertainties are described, and the estimation of uncertainty components and the calculation of combined uncertainties are also studied. It is emphasized that the transducer is one of the fundamental sources of VI's measurement uncertainties, and the B type uncertainty of VI must be verified by standard instruments. An example of average measurement of direct voltage is used to explain that the mean value of N time measurements improves the precision of measurement result greatly. The proposed method was used in the design of a synthesized low frequency electrical parameter calibration instrument, which validates the correctness of the method.