INTRODUCTION 



tional performance, they indicate the relative im- 

 portance of the parameters and thus establish the 

 changes in design most effective for improving op- 

 erational performance of the gear. As desirable im- 

 provements are often inherently contradictory, these 

 studies may be useful in indicating the most advan- 

 tageous compromise, not only for gear in general, 

 but in view of particular conditions of service, and 

 also for particular types of equipment. 



The studies have been carried out on a more com- 

 prehensive basis directed toward evaluating the rela- 

 tive effectiveness of different classes of gear by infor- 

 mation obtained in controlled surroundings. 



1.3.3 Relation to Manufacturing 



Requirements and Specifications 



There is still another important application of 

 fundamental calibration measurements on under- 



water sound gear, namely, as an aid to the establish- 

 ment of manufacturing acceptance requirements. 

 Whenever it is necessary to manufacture equipment 

 in production quantities, it is often impossible, be- 

 cause of considerations of time and facilities avail- 

 able, to test completely each unit produced. It is 

 therefore necessary to examine critically those fac- 

 tors of prime importance in determining satisfactory 

 operation ol the equipment, and to establish limits 

 of acceptable performance. These limits should be 

 primarily based on careful studies of the gear under 

 controlled conditions, keeping always in mind the 

 influence of the various factors on operational per- 

 formance. 



Thus calibration measurements under controlled 

 conditions not only are an aid in determining speci- 

 fications but also suggest methods for determining 

 whether manufactured equipment is within the lim- 

 its set by the specifications. 



