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OCEANOGRAPHIC INSTRUMENTS FOR MEASURING TEMPERATURE* 



Allyn C. Vine 



INTRODUCTION 



A great deal of oceanographic effort in the past has gone into measuring 

 ocean temperatures and determining how they vary with location, season and 

 depth. For some problems, such as thermal flow, the measured temperature 

 variations are the primary end. In other problems, temperature variations 

 which are rather easy to measure give excellent correlation with some desired 

 variable which is not easy to measure directly. 



Temperature measuring equipment in oceanography has tended to be very 

 simple for several reasons. First, the majority of the experimental oceanog- 

 raphers in the past were biologists rather than physicists or engineers. Second- 

 ly, when complicated apparatus was built and used, it usually either failed to 

 work satisfactorily on shipboard or it would only work for the builder. Thirdly, 

 the trend in almost any field work is to adopt the available instruments which 

 give the least trouble and then they soon become the generally accepted instru- 

 ments. 



It is the purpose of this paper to describe some of the temperature meas- 

 uring instruments which have been used, and the principal types of temperature 

 measuring elements and systems. The principal effort, however, will be 

 placed on trying to analyze the temperature problems we are confronted with, 

 the limitations of present day instruments, and outlining new types of instru- 

 ments that should be successful in attacking these problems. 



OLDER INSTRUMENTS 



Because of the relative ease of measuring temperatures compared to 

 measuring salinity, density, or current, it has remained important not only as 

 an end in itself but also as an indicator. It is presumed that this trend will con- 

 tinue and that temperature measurements will continue to be one of the most 

 powerful and versatile ways we have of figuring out our oceanographic puzzle. 



During the years we have gradually accumulated enough temperature 

 measurements to obtain a rough overall picture of the northern Atlantic and 

 Pacific which is reasonably descriptive for large scale phenomena. We are 

 sadly lacking however to describe in a detailed way how thermal exchanges take 

 place or to predict small scale oceanographic features. 



Bucket and Thermometer - In order that this paper can have as simple a begin- 



* - Contribution No. 696 from the Woods Hole Oceanographic Institution. 



