Formulas to correct excess pressure and pressure shift to be used in volume measurement for plutonium nitrate solution

Excess pressure caused by the bubble and the pressure shift resulting from the air column in a dip-tube pressure measurement are the error sources to be considered for highly accurate density, level, and volume determination of plutonium nitrate solution in a tank. A new approach to estimate the max imum, the minimum, and the average of oscillating excess pressure as a func tion of tube diameter d, solution density rho, and surface tension CT witho ut including height, curvature, and amplitude of the bubble is proposed. Th is approach can be applied sigma without reducing the rate of downward airf low that is necessary to prevent contamination. When the estimates were com pared with the experimental results in a water-ethanol system within the ra nge 3.6 X 10(-6) less than or equal to sigma/(rho g) less than or equal to 7.4 x 10(-6) (m(2)) and 1.8 less than or equal to d root rho g/sigma less t han or equal to 9.6 the mean of the difference was <2 Pa. The estimate for the maximum excess pressure was also compared with the conventional formula , and the difference was <1 Pa. We also proposed an equation to estimate th e surface tension of the plutonium nitrate solution. For the pressure shift , a new formula assuming that the air density varies exponentially in the t ube is proposed. The measured differential pressure is proportional to the hydrostatic pressure, and the coefficient is nearly independent of the liqu id level. These correction factors of excess pressure and pressure shift ca rt practically be given as constants.