ABSTRACT 



CERC has used wave gages to gather prototype wave data since 1948. 

 Two basic types of gages are now used in the field - the step-resistance 

 staff gage and the underwater pressure-sensitive gage. CERC has developed 

 three types of step-resistance staff gages - a series type for use in 

 fresh water, a parallel type for use in salt water, and a relay-operated 

 type for use in either fresh or salt water or in water where wide changes 

 in salinity occur. The pressure gage can be used in water of any salinity. 

 The series and parallel gages have an accuracy of ±5 percent plus the 

 spacing of one sensor increment. The relay gage has an accuracy of ±2 

 percent plus the spacing of one sensor increment. The accuracy of the 

 pressure-sensitive gage is not as precise as that of the step-resistance 

 gages . 



The report describes each gage and the theory of operation, details 

 of fabrication, steps for calibration and installation, and requirements 

 of maintenance. 



FOREWORD 



This report describes in detail the sensors and recorders used by 

 CERC in wave-data collection programs. Leo C. Williams, Chief of the 

 Instrumentation and Equipment Branch, Research Division, prepared this 

 report and developed most of the wave-data equipment used at CERC. 

 Thorndike Saville, Jr. is Chief of the Research Division. The 

 manuscript was prepared in 1966. 



Many drawings in this publication have been greatly reduced from 

 the originals. The large originals are available at CERC in limited 

 quantities . 



At the time of publication. Lieutenant Colonel Edward M. Willis 

 was Director of the Center; Joseph M. Caldwell was Technical Director. 



NOTE: Comments on this publication are invited. Discussion will be 

 published in the next issue of the CERC Bulletin. 



This report is published under authority of Public Law 166, 79th 

 Congress, approved July 31, 1945, as supplemented by Public Law 172, 

 88th Congress, approved November 7, 1963. 



