In this paper

a holistic tracing method is proposed in order to avoid the problem that the effective traceability can not be implemented for single digital measuring device. The relationship between digital measuring devices’ error and holistic power measuring error is analyzed

meanwhile mathematical model is established and error analytic expression is obtained. The holistic verification scheme is designed aiming at typical digital measuring scheme in smart substations. The possible problem in the calibration process is estimated and the corresponding solutions is provided. In a substation under construction as an example

the field calibration for the whole digital measurement is carried out

and the error calibration data are counted and analyzed. The local calibration result indicates that the holistic calibration method is correct and effective.