This European Standard defines the minimum performance requirements of on-board monitoring systems for axlebox condition monitoring by means of temperature measurements. This European Standard refers to temperature monitoring of the axlebox. However, the design may be such that the rolling bearing itself is monitored directly. The requirements of this European Standard are intended to apply equally to basic monitoring systems for monitoring the axlebox temperature through to more technically complex systems that may employ a combination of mechatronics. To ensure the compatibility of monitoring systems and the effective monitoring functions, this European Standard defines the requirements in the following areas: - equipment and characteristics; - monitoring performance; - operation and interface. This part of EN 15437 does not include: - systems that do not give an indication to the driver; - how an on-board monitoring system is structured and how it measures the temperature and identifies axlebox position. This is considered part of equipment design and not part of the functional requirements set out in this standard; - operational requirements for acting on the information reported by the on-board monitoring system; - operational requirements for conflict of information between trackside monitoring systems and on-board monitoring systems; - maintenance requirements for on-board temperature monitoring systems.