Patent US 5,020,007

A method for monitoring the health of a physical system that produces waste heat as a function of ambient temperature includes the generation of a standard profile model of the system in good health and a degraded profile model of the system in bad health, each profile being within the same family of curves. The monitored system is then sampled for sample ambient temperature and sample waste heat temperature to generate a system degradation indicator, preferably as a percentage of degradation. Alarms and displays present relevant warnings and information to the user. Waste heat affecting variables in addition to ambient temperature may be included in the standard and degraded profiles, and these variables may be monitored to produce the degradation indicator. The method is preferably microprocessor controlled.