Mathematical models of system-oriented measuring instruments

System-oriented measuring instruments (MIs) differ from traditional MIs in their ability to be integrated into complex control and automation systems. They are tools that are used in various complex technical systems to collect, analyse, transmit and use measurement data in real time. Such MIs are an important element in the implementation of the concept of Industry 4.0, where it is crucial not only to measure parameters, but also to use them for intelligent control of various technical processes. Mathematical models allow to theoretically simulate the operation of a certain complex technical system to identify opportunities for its optimization and improvement of certain of its technical characteristics. The construction of a certain mathematical model of a technical system shall provide the maximum reflection of all the main properties of the modelled system. There are various methods for mathematical modelling of complex technical systems. However, there is no general procedure for creating such models. The main components of system-oriented MIs are determined and their generalized structural diagrams of two types of such MIs are proposed. A generalized structural diagram of an information and measurement complex based on a combination of system-oriented MIs is presented, which allows performing measurements and processing of measurement data from numerous measurement objects. For mathematical modelling of a system-oriented MI as a system, the graphical and analytical apparatus of the general systems theory was used. The combination of graphical and analytical interpretations of the obtained mathematical model provides the necessary information about the properties of the MI as a complex technical system. The obtained mathematical models can become the basis for evaluating the specific components of measurement uncertainties when using a system-oriented MI.