Int J Adv Manuf Technol (1999) 15:711–721  1999 Springer-Verlag London Limited Commercial Tool Condition Monitoring Systems K. Jemielniak Warsaw University of Technology, Institute of Manufacturing Engineering, Warsaw, Poland One of the most significant developments in the manufacturing environment is the increasing use of tool and process monitor- ing systems. Many different sensor types, coupled with signal processing technologies are now available, and many sophisti- cated signal and information processing techniques have been invented and presented in research papers. However, only a few have found their way to industrial application. The aim of this paper is to present the state of the art in commercially available tool condition monitoring systems and to compare it to reported research achievements. Keywords: Industrial application; Tool monitoring 1. Introduction The quest for process automation is driven by the growing costs of human labour and quality demands and makes the monitoring of manufacturing systems inevitable. Therefore, extensive research work is taking place world-wide in the area of tool and process condition monitoring, which has been one of the most important focuses of research effort for more than twenty years. Numerous papers have been published (see eg. [1–3]) presenting many ideas, and many approaches have been proposed to accomplish tool condition monitoring. In the nature of scientific research, there is a gap between science and technology. There is a time lag between research and commer- cialisation, and any new technology takes time to mature [8]. Some work in this field can be used in commercially available systems. Other work is still in the exploratory stages. There may be several ideas and possibilities for studying certain phenomena, which all show the potential to become new and useful commercially profitable techniques. However, many of them will never be applied, as they will prove to be unreliable or not economic. As actual use in a commercial system is the final justification of the applicability of any research work Correspondence and offprint requests to: Professor K. Jemielniak, Warsaw University of Technology, Institute of Manufacturing Engineering, Narbutta 86, 02–524 Warsaw, Poland. E-mail: k.jemielniakwip.pw.edu.p1 concerning tool condition monitoring, reviewing such systems is worthwhile. Each tool condition monitoring (TCM) system consists of (Fig. 1): sensors, signal conditioners/amplifiers and a monitor. The monitor uses a strategy to analyse the signals from the sensors and to provide reliable detection of tool and process failures. It can be equipped with some signal visualisation system and is connected to the machine control. All these elements will be discussed here. Although there are many firms offering various tool condition monitoring systems and equipment, six leading suppliers are considered in this survey: Artis; Brankamp; Kistler; Montronix; Nordmann and Prometec. 2. Sensors The sensor is a key element of any tool/process monitoring system. Although numerous different sensor types have been invented and applied in laboratories [5], only a few are now Fig. 1. Example of tool condition monitoring system configuration [34].