IEC62368-1 Figure 47 Steel Disc/ Aluminium Ring/Aluminium Foil for Wireless Power Transmitter Foreign Object Temperature Rise Thermocouple

IEC62368-1Figure 47 steel disc,aluminium ring,aluminium foil for wireless power transmitter foreign object temperature rise thermocouple
Wireless power transmitter for near field wireless power transfer can warm up foreign metallic objects that may be placed close to or on such a transmitter. To avoid a burn due to high temperature of the foreign metallic objects
The following foreign objects are used:
a steel disc see Figure 47
an aluminium ring, see Figure 48 
an aluminium foil see Figure 49

The wireless power transmitter is placed is a room under  the temperature conditions 
The test is performed once with each of the foreign objects placed in direct contact with the transmitter. Each test has four cycles:
one without a receiver present and with the foreign object in direct contact with the transmitter
one with a receiver placed in direct contact with the foreign object
one with a receiver placed at a distance of 2mm from the foreign object
one with a receiver placed at a distance of 5mm from the foreign object
The transmitter is operated to transmit its maximum power.
Note: The test is not meant to test the temperature of the receiver, therefore any compatible receiver that can draw the maximum power from the wireless power transmitter can be used and the temperature of the receiver does not have to be monitored.
During each cycle,the foreign object can be moved on the transmitter in order to find the location where the highest temperature occurs.
During the tests, the temperature of the foreign object shall not exceed 70ºC