Long-term performance of the L3 RPC system

Abstract Started in 1994 the L3 experiment has been equipped with a forward–backward muon spectrometer triggered by an RPC system. Made of 192 double-gap RPCs, it has been working for six years in streamer mode and it will continue to run at least one year more. We monitored the behaviour of the system during the L3 run periods and in this paper we report on its present status and long-term performance.