PREFACE vii 



systems that are commonly in use and to some unorthodox methods 

 that seemed to hold some promise for further development. Older 

 instruments are included if the principle involved is of general 

 interest or possibly applicable in other techniques. Experience 

 shows that old or neglected methods are frequently revived after 

 having undergone a metamorphosis or some improvement. Some 

 special methods, like those used for the establishment of standards, 

 are omitted. 



Different parts of this book have been written at different times; 

 in general, it reflects the status of the art of instrumentation be- 

 tween the years 1955 and 1957. However, the book is not intended 

 to be the most "modern-minded" text, but rather a presentation of 

 the basic methods. The development of these basic systems is slow 

 and only moderately affected by new publications. 



Information on instrumentation is scattered widely throughout 

 the entire literature in physics, biology, medicine, and the engineer- 

 ing sciences. The classic book on methodology is the "Praktische 

 Physik" originated by F. Kohlrausch (last edition edited by H. 

 Ebert and E. Justi and published by Teubner Verlagsgesellschaft 

 m.b.H., Stuttgart, 1956). A number of periodicals are exclusively 

 devoted to this science, such as the Review of Scientific Instruments 

 (American Institute of Physics, New York), the Journal of Scientific 

 Instruments (The Institute of Physics, London), and the Archiv fur 

 technisches Messen (R. Oldenburg, Munchen). A considerable con- 

 tribution has been made by the collections of books published after 

 World War II by laboratories operated by the government (e.g., 

 M.I.T. Radiation Laboratory Series, National Nuclear Energy 

 Series, both McGraw-Hill Book Company, Inc., New York). I have 

 freely drawn from these sources as well as from summarizing papers 

 and reviews. Also, I have not hesitated to include material found 

 in pamphlets and advertising literature of commercial companies. 

 These papers are sometimes clearer and less pretentious than 

 "scientific" publications, and I believe that a great deal of our post- 

 graduate education comes from such company literature. The 

 similarity between teaching and advertising has been strikingly 

 demonstrated by Gilbert Highet in "The Art of Teaching" (Alfred A. 

 Knopf, Inc., New York, 1950). 



I have frequently found that a very extended bibliography is of 

 little help. Therefore, I have limited myself to those references 

 which seemed most important. They are not always the first de- 

 scriptions of any method nor the most extensive publications but 

 generally those that seemed to be most informative or most clearly 



