13 



ratio -^^must not exceed 0.02. 



Q 



The range of the instrument described extends to 20 in. of water (single peak amplitude). 

 The ratio -^ for this largest amplitude is approximately 0.012 so that the bridge nonlinearity 

 does not exceed 0.6 percent of full scale on this sensitivity setting and is considerably less 

 for the measurement of smaller wave amplitudes. 



REFERENCES 



— > 1. "An Ocean Wave Measuring Instrument," Technical Memorandum No. 6, Beach Erosion 

 Board, U.S. Army Engineers, Vicksburg, Miss., October 1948. 



2. Chinn, A.J., "Progress Report on Wave Measurements at Apra Harbor, Guam," Univer- 

 sity of California Department of Engineering Report No. HE- 152-2, 5 July 1949. 



3. Cook, G.W., "A Resonant-Bridge Carrier System for the Measurement of Minute Changes 

 in Capacitance," TMB Report 626, February 1951. 



