RT Journal Article SR Electronic T1 Assessment of Photomultiplier Tube Balance JF Journal of Nuclear Medicine Technology JO J. Nucl. Med. Technol. FD Society of Nuclear Medicine SP 157 OP 159 VO 7 IS 3 A1 Caprio, Michael L. A1 Tenpenny, Richard YR 1979 UL http://tech.snmjournals.org/content/7/3/157.abstract AB We developed a quick and simple test to determine photomultiplier tube balance using a small disk source of Co-57. Using this procedure assures that imbalanced photomultiplier tubes will be located and corrected before image quality is affected.