George W. Burkett, Jr.;Sarah E. McKenney;John M. Boone
发明人:
John M. Boone,George W. Burkett, Jr.,Sarah E. McKenney
申请号：
US13550502
公开号：
US09008264B2
申请日:
2012.07.16
申请国别(地区):
US
年份:
2015
代理人:
摘要：
Described is an apparatus for use in HVL measurement as well as methods of making measurements. One version of the apparatus is a cage structure having a central axis and a central opening defined by a filter encircling the central axis, with the filter having a thickness that varies peripherally around said central axis. The filter can be formed from multiple spaced-apart plates having varying thicknesses or can be formed from a cylinder having a continuously increasing thickness.
