Chromatic monitoring of plasma and plasma systems

Chromatic systems were originally developed for monitoring the optical emis sions of plasma. This contribution describes how the technology has been ut ilised on low- and high-pressure plasma systems. The speed of operation of chromatic systems has allowed their use in the monitoring of fast changing plasma, such as arcs and laser plumes. The chromatic methodology has now be en extended from the optical domain and is used for more general signal pro cessing. This more general application of the chromatic method is outlined and is related to the plasma processing industry. (C) 2000 Elsevier Science Ltd. All rights reserved.