Plots of Kp (automated method) versus time in the fixed-bed tanks are 
shown in Figure 1. The fixed-bed values of Kp varied from 0.03 to 0.06 
in experiment 72B-06 and from 0.02 to 0.09 in experiment 72B-10, with no 
long-term drift in either experiment. This variation represents all 
errors involved in measuring Kp from the changing profile in the neigh- 
boring tanks, and thus the error in Kp measurements in the movable-bed 
tanks was +0.015 in experiment 72B-06 and +0.035 in experiment 72B-10. 
The Kp data in the movable-bed tanks as determined by the two 
methods are compared in Figure 2. Kp values for the manual method ver- 
sus the automated method for those wave records reduced by both methods 
are shown in a scatter plot (Fig. 3). The plot indicates that the manual 
method values were higher than the automated method values by an average 
of 0.07 in experiment 72B-06 and in range 5 of experiment 72B-10 (enclosed 
points), and that the difference was not a function of the magnitude of 
Kp, since the data are parallel to the 45° line. The data for the out- 
side ranges in experiment 72B-10 show a larger difference between methods 
and a greater scatter, as a result of the transverse wave. The effect of 
the transverse wave on a wave envelope appears as a longer wave super- 
posed on the standing wave. The automated method removes any long wave 
effect and thus would have been much lower. 
Kp versus time for experiment 72B-06 is plotted in Figure 4, with 
the manual method values reduced by 0.07 to give a single curve. During 
the first 30 hours the Kp fluctuated, but the maximum values gradually 
declined. After 30 hours the Kp began increasing, with continuing 
fluctuations about the increasing mean. The maximum value of 0.14 
occurred at 125 and 140 hours. 
Kp data from the center range of the movable-bed tank of experiment 
72B-10 versus time are plotted in Figure 5, with the manual method values 
reduced by 0.07. The Kp increased for the first 10 hours and then 
fluctuated about an average 0.16 between 10 and 90 hours. During the 
last 60 hours the Kp values fluctuated about a mean of 0.21. 
c. Transverse Waves. Transverse waves in experiment 72B-10 caused 
the wave to appear to wobble as it traveled down the wave tank. At about 
Station 40 (about 15 feet (4.6 meters) from the wave generator) the crest 
was higher than the generated wave (range 5) along range 1 and lower along 
range 9. Near station 25 the crest was higher along range 9 and lower 
along range 1 and near station 10 the crest was again higher along range’ 
1 and lower along range 9. 
The transverse wave can be seen in the wave records of the standing 
wave envelope recorded by the moving wave gage at 55 hours along ranges 
1, 5, and 9 (Fig. 6). Assuming that the variation is due to the trans- 
verse wave, the envelope along range 5 is representative of the generated 
wave, unaffected by the transverse wave, since this is the centerline of 
the tank. Along range 1 the maximum wave height occurred near station 25 
and the minimum near station 39, and along range 9 the maximum occurred 
18 
