Classification of electrical measuring equipment

Conclusions

The above problems for classifying electrical measuring equipments with respect to various characteristics of transformation and of converters which form part of electrical measuring instruments, reveal the extent of diversity in the design of modern measuring instruments. It should also be noted that all the above reasoning refers only to so-called “measuring” transducers which affect directly the properties and characteristics of instruments. In addition to the measuring converters, modern instruments also comprise supplementary converters, for instance, in the supply circuit, which function as rectifiers, stabilizers of the supply voltage, etc., thus still further complicating the design of the instrument.

Hence, it is simply impossible to classify the electrical measuring instruments by their design, or by any single characteristic which determines the design of the instrument and its properties.

In designing electrical measuring instruments, it is necessary to examine (or compile) a technical specification by means of all five classification features.

The problem of selecting the type of input (receiving) and output conversion follows directly from the intended use of the instrument.

Sometimes the instrument's application also determines the type of the input and output transducers.

Having determined the type of conversion at the input and output of the Instrument, it is necessary to select the system of the measuring input transducer. Sometimes this problem has only a single possible solution, in other instances it is necessary to choose a system for the input receiving transducer from several possible systems.

Now it becomes possible to select the type of modulation and the method of conversion by weighing up such technical and economic considerations as accuracy, frequency range, speed of operation, complexity of the design, possible cost, etc.