Ensuring uniformity of measurements in the European Metrology Cloud

The main requirements for the calibration of measuring channels of distributed measuring instruments at the operation site are described. When preparing for calibration, the use of portable discharge working measurement standards, which consist of a reference voltage source and a divider, is substantiated. The proposed structure of the device for calibration is based on a divider of single-nominal resistors and corresponding algorithms for processing the conversion results. The feasibility of using a divider in which the resistors are closed in a ring is substantiated. To ensure the invariance to residual parameters of switching elements when implementing several evenly spaced calibration points in the conversion range, a potential-current switching of both the input reference voltage and the output converted voltage is proposed. In addition, a method to correct the equivalent additive error component of the entire measuring channel during its calibration is proposed. The expediency of the studied measuring channels to obtain intermediate conversion results is shown. An algorithm and method of processing intermediate conversion results to obtain code values at all calibration points are proposed. To process these results, it is advisable to apply an additional software in the European Metrology Cloud. It is shown that the calibration error of the measuring channels at the operation site is determined by the error of the reference voltage source.