The ASTM F 2391-22 standard test method provides a standardized nondestructive detection scheme for the measurement of Encasement and sealing integrity using helium as a tracer gas. The method is suitable for a variety of Encasement types, including flexible, semi-rigid, and rigid Encasement, and is capable of detecting leaks from 100 μm to 0.01 μm in diameter. The test is divided into two types: Sniff mode is used to externally scan for helium leaks, while vacuum mode places the package in a closed fixture and detects helium escape by vacuuming. The method is suitable for areas such as Encasement design, tool evaluation, process validation, and mass assurance. Sensitivity ranges from detecting large leaks to ultra-fine leaks and can be used with a variety of Encasement materials, but not for breathable or porous Encasements.