Both the ion current density and the ion energy are required in order to electrically characterise a low pressure plasma or ion beam. These properties are of importance if close control of a surface treatment process is to be obtained. A Faraday Cup provides the necessary means by which to monitor these plasma properties even in a wide variety of noble and reactive gas plasmas. The work presented in this paper describes the characterisation of an Argon plasma beam produced using a low pressure inductively coupled plasma source using CCR's new Faraday Cup CEA3 Plasma Monitor System.