Calibration curves and dynamic characteristics are widely used as metrological models of measuring instruments properties; but the initial concepts and formal representations have not been clearly formulated so far. This paper focuses on the construction of a formal framework, which should enable introduction and estimation of adequacy as a characteristic of the model quality. The formal system is constructed, that is similar to the representative theory formalization. So, an initial model for calibration curve is a complex {U, C-0, Phi}, containing a set of dependences U, a space of continuous monotonous functions C-0, and monotonic homomorphism Phi: U -> C-0. Construction of calibration curve is started from an initial table of experimental data, and transfer to the analytical form of calibration curve is analysed. It is demonstrated that adequacy parameters should be expressed by functionals of both measurement accuracy and frequency range. The analogy of measurement and modelling of metrological characteristics should be extended up to the construction of system ensuring the traceability of calibration curves and dynamic characteristics. This system can be created using the experience in constructing a system ensuring the measurement traceability.
