Laboratory high performance test equipment is too expensive and bulky for on-site fuel cell stack evaluation. Yet cell voltage monitoring appears from safety assessments to be a crucial element in operating a fuel cell system. in this paper a dedicated cell voltage monitoring system for on-site applications is evaluated. It describes the specific concept of the on-site monitor system, shows measurement results of its specifications for safety, control and long-term evaluation and presents a comprehensive comparison with laboratory equipment. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.