PART III: INSTRUMENTATION 



18. This part identifies the instruments used for monitoring oceano- 

 graphical and meteorological conditions and briefly describes their design, 

 operation, and location. More detailed explanations of the instruments may be 

 found in Miller (198O). Equipment used for other types of data collection, 

 such as the surveying system, are not generally discussed; however, references 

 are provided in Part IV. 



Meteorological Instruments 



Air temperature 



19. A Yellow Springs Instrument Company, Inc. (YSI), Yellow Springs, 

 Ohio, electronic temperature probe with analog output interfaced to the FRF's 

 Data General NOVA-4 was operated beside the National Weather Service's (NWS's) 

 instrument shelter located 43 m behind the dune (Figure 2). To ensure proper 

 temperature readings, the probe was installed 3 m above ground inside a "coo- 

 lie hat" to shade it from direct sun yet provide proper ventilation. 

 Maximum/minimum thermometers 



20. Maximum and minimum thermometers housed in the shelter were used to 

 determine the daily extreme air temperatures. The shelter was designed with 

 louvered sides, a double roof, and a slatted bottom for housing instruments 

 requiring protection from direct sunlight. 



21. The actual temperature readings at the time the thermometers were 

 read were compared to ensure accuracy of the maximum and minimum values. 

 Maintenance consisted of the periodic removal and cleaning of the thermometers 

 with soap and water and lubricating the Townsend support used to hold and re- 

 set the instruments. 



Atmospheric pressure 



22. Atmospheric pressure was measured with a YSI electronic sensor gage 

 with analog output. The sensor was located in the laboratory building at 9 m 

 above NGVD, and data were recorded on the FRF computer. Data from this gage 

 were compared with a NWS aneroid barometer at least once a week to ensure 

 proper operation of the instruments. 



23. A recording aneroid sensor (microbarograph) located in the labora- 

 tory building was used to continuously record atmospheric pressure variation. 



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