Ultra high purity aluminum has proven to provide more accurate measures of half value layer in mammography than aluminum alloys.
Whilst the aluminum supplied in the 115A is appropriate for testing non-mammographic systems, it is insufficiently pure for accurate testing of mammographic systems. The Gammex 115H Half Value Layer Attenuator
Set provides the needed substrate purity for accurate MQSA HVL compliance. The set consists of six 10cm x 10cm x 0.1mm sheets of 99.99% pure aluminum, and includes a plastic storage case to protect and help maintain flatness of the filters.