Oneida RAD Equation

This page is related the Krypton 85 (Kr85) leak testing, as described in Mil-Std-883 TM-1014 and Mil-Std-750 Test Method 1071 documents.

In order to measure the leak rate of hermetically sealed cavities, a pressurization is performed with a tracer gas containing small quantities of radioactive Kr85. This gas penetrates inside the cavity of the device. At the end of the pressurization, the radioactivity of the Kr85 trapped inside the cavity is measured, and is directly linked to the size of the leak.

The “Oneida RAD™ Equation” computes the measured radiation (Rad), for a leak showing purely molecular flow, as a function of the leak size (L), internal volume (V), pressurization parameters, tracer gas and radiation detection characteristics. This equation was established from gas molecular flow  and radiation measurements equations and differs from the Radiflo equation generally used for Kr85 testing.

The interactive form below helps you compute the Rad Pass/Fail criteria based on your leak test parameters. The form also does the reverse computation (i.e. it computes the Total Leak Rate (L) from the Measured radiation (Rad)).

The aim of this tool is also to compare the behavior of these two equations (“Oneida RAD™” vs “Radiflo”).

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