6 INSTRUMENTATION IN SCIENTIFIC RESEARCH 



The reader should be reminded that the book deals only with elec- 

 trical transducer systems. Systems based on other physical prin- 

 ciples, such as optical or acoustical systems, are occasionally included 

 when it was felt that they are closely related to the field of electrical 

 transducers. 



The described breakdown of instruments into their elements not 

 only permits a satisfactory organization of instrumentation systems, 

 but also furnishes a logical code for the identification of instruments 

 of any kind. Such a code can be used much in the way a chemist 

 uses the symbolic description of chemical compounds, either for the 

 characterization of instruments or for information retrieval in the 

 instrumentation literature. 



