This International Standard is applicable to industrial radio- or high-frequency induction heating installations used for the purpose of thermal applications (e.g. for surface hardening, welding, soldering, melting, forging, zone refining of semiconductors, etc.). This standard relates to high-frequency induction heating installations in the frequency range up to 300 MHz for power levels of 500 W and above, comprising high-frequency generators and inductors together with necessary mechanical devices for charge handling (e.g. hardening machines). The main purpose of this standard is to provide the test methods for the determination of output power of industrial high-frequency induction heating power sources. Loads as described in this standard may be used in compliance assessment of electromagnetic compatibility according to CISPR 11. This standard relates to generator capacity of operation under continuous rated conditions as specified by the manufacturer. The methods of measurement of power output of generators operating in pulse mode with short duty cycles (e.g. the adiabatic calorimeter) are under consideration. Electronic systems of power measurement are commercially available, but care must be taken in their application because accuracy can not be guaranteed, particularly at higher frequencies. These instruments require high current transformers and voltage transformers for the output power measurements and they also are subject to errors at higher frequencies. These methods require expert knowledge for successful application and therefore are not detailed in this standard.