Detalhes do Artigo
[306926] A closer look at the mathematical model of a cryogenic current comparator
Autores: Vinicius Coutinho De Oliveira, Regis Pinheiro Landim, Charles Bezerra Do Prado
Resumo: A virtual resistor is a hardware and software assembly that realizes a control system to emulate “traditional” resistive components without the loss of energy efficiency that they entail. There are possible applications for virtual resistors to the Metrology in Electrical Resistance Standardization. However, as in any control system analysis, it is necessary to build proper mathematical models. Hence, a white-box modeling approach is required to understand the physical phenomena that affect the variability of measurements performed with resistance comparator bridges. This paper discusses how to start building a mathematical model for a resistance comparator bridge based on a commercial cryogenic current comparator. The data collection and statistical analyses necessary for refining such a model are presented. Results indicate that the current values along a measurement do not always fit a normal distribution. Moreover, there are some cases where one cannot assume that the current value is constant over the measurement period, i.e., there is a noticeable trend for current drift.