ONEIDA RAD™ EQUATION (KR-85)
The Oneida RadTM Equation is a new model for calculating standard leak rates from the Radioisotope leak test method. It is modeled on the procedures defined in MIL-STD-883L Method 1014, Test Condition B, but seeks to reconcile errors produced by the Radiflo equation. The Oneida RadTM Equation is derived in the same manner as the Howl-Mann equation, that is, it assumes a molecular flow regime. Whereas, the Radiflo equation is derived from the laminar flow equation presented in the Howl-Mann paper, but also assumes a constant gas flow rate, which is proportional to the difference of squared initial partial pressures of that gas on the interior and exterior of the enclosure. This erroneously implies that a gas may accumulate indefinitely inside the enclosure, beyond the point which equilibrium between the partial pressures of the gas is reached. For suitably small-volume enclosures, the Radiflo equation may assert a continued accumulation of Krypton-85, when in reality, equilibrium partial pressure has already been reached. In this case, the test procedure would report a radiation count below the rejection threshold, thus rendering an affirmative test result, when in reality, the true standard leak rate is unknown, and maybe failing.