of a fully-developed, low-priority instrument merely because all 

 of the higher priority instruments have not yet come into being. 



A general requirement for all instruments and instrument 

 systems, excluding those whose sole function is the collection of 

 various samiples, is that the data which they collect must be able 

 to be read directly into the Master Shipboard Data Logging and 

 Processing System. This requirement remains regardless of whe- 

 ther the informiation is internally recorded within the instrumient 

 or system vehicle or whether the instrument or system transmits 

 or telemeters the data directly to the survey vessel. In this 

 connection, the final data output of the Master Shipboard Data 

 Logging and Processing System must be in proper form for direct 

 inclusion in the archives of the National Oceanogr aphic Data Center. 



Modular construction, both of sensors and of consoles, has 

 been particularly specified in these instruments and instrument 

 systems. This has been done primarily to facilitate field mainten- 

 ance and repair; however, it also allows for the different lengths 

 of time that may be required to develop any given sensor. Addi- 

 tional factors, which have prompted specification of this mode of 

 construction, are: 



1. Higher resolutions and accuracies are more economically 

 attained with a group of modular sensors, each interchangeable and 

 covering a different sensing range; 



Z. A greater demand may be generated for a particular sen- 

 sor than the overall demand indicated in these descriptions for the 

 total instrument or systems; 



3. Standardization will afford the widest possible sensor appli- 

 cation and market, inasmuch as many of these sensors are to be 

 utilized in more than one of the described instruments and instru- 

 ment systems; 



4. Interchangeable, modular sensors will permit many com- 

 panies, who may have neither the interest nor the capability to 

 contract for an entire system, to devote their specialized talents 

 to development of a particular sensor. This is expected to be 

 especially true of companies having a specialized chemical analy- 

 sis capability. 



In conjunction with this policy of modular construction, vehicles or 

 350 



