title: Quality control of gamma counters. I. Experimental evaluation of sources of error.
abstract: Errors of counting rate as large as 2 percent may occur through variations in instrumental parameters during the measurement of I-125 activity using a gamma counter. Much larger errors result from failure to maintain constant sample geometry; in particular, the slope of calibration curves depends on sample volume.
mesh_terms: D011786:Quality Control; D012588:Scintillation Counting / Q000295:instrumentation / Q000592:standards*; D013051:Spectrometry, Gamma / Q000379:methods / Q000592:standards; D013696:Temperature; D013997:Time Factors