A.G. Borisov, A.P. Kazantsev, G.A. Sadovskiy

This article outlines the approach to analysis and synthesis of instruments based on the persistence of measurement information, as product of quantity of information in one sample of input process by sampling rate, and measurement period. An instrument is considered as a chain of information converters. It is shown that for equivalence of input and output process, it is necessary and sufficient in each conversion to maintain amount of information received from the object under measurement. Providing each time of conversion is equal the others, the quantity of information in one sample and bandwidth are exchangeable at adjacent conversions. Information-frequency exchange is demonstrated by an integrating ADC as an example of analysis. As another example, minimal resolution requirements are exhibited for fast sampling ADC at synchronous analyzer. In some cases quantity of information in one sample is less than one bit. In such a case one might make use an analog comparator as an ADC. Concluded that amount of measurement information persistence in the conversion chain appears as an effective criterion for instrument adaptation. Main results are the following: definition on amount of the measurement information is given; the instrument input and output equivalence conditions, as well as the persistence conditions for amount of information in the conversion chain are stated; the information-frequency transformation is expressed mathematically; the application of the information persistence criterion are demonstrated in examples.