chemical reaction in the conducting fluid surrounding the Waverider accelerom- 
eter. These three corrections and their application are discussed below. 
Datawell-Predicted Decrease in Sensitivity Error DW 
3. Waverider buoy sensitivity /A/ for the buoy electronics decreases 
with increasing period T of sinusoidal vertical motion according to Datawell 
as follows: 
/A/ = = (A1) 
Where T, = 30.8 sec is a characteristic period provided by Datawell. This 
sensitivity decrease results in amplitude errors of less than 3 percent for 
oscillation (wave) periods less than 15 sec. Figures Ai to A3, which present 
curves for the Datawell-predicted sensitivity decrease error (DW) = /A/ - 1, 
show that the actual sensitivity does not decrease with period according to 
the Datawell relationship given in Equation Al. 
Difference Error d 
4, Difference error d is the difference between the Datawell- 
predicted decrease in sensitivity error DW and that found from the actual 
buoy calibrations. In Tables A2 through A4, DW and d are tabulated as a 
function of T for each buoy. Best accuracy is obtained by choosing the 
calibration values nearest in time to the date of the measurements. 
Temperature Related Error 
5. It has been determined that for some unknown number of Waveriders 
the sensitivity is drifting downward, possibly since manufacture, on the aver- 
age of about 1 percent per year. Sensitivity loss from some unknown chemical 
reaction is related to increases in electrical conductivity of the conductive 
fluid surrounding the accelerometer. This drift is identified from calibra- 
tions over a period of time. 
A2 
