IPEM Report 85 is a handbook for radioactive sample counters including gamma counters, liquid scintillation detectors, intraoperative gamma probes and automatic blood sampling systems.   The report summarises the physical principles of radioactivity detection and outlines the operational properties of sample counting across the different sample counting systems.  This second edition builds upon and expands the original Report 85 first published in 2002. Even though the physical principles of sample counting remain the same, the counting equipment has improved, and its applications have diversified.  The new edition includes updated information on (1) counting equipment design and operation; (2) equipment specification and quality assurance procedures; and (3) worked examples of clinical, research and industrial applications of radioactive sample counting.  Part of IPEM-IOP Series in Physics and Engineering in Medicine and Biology.