For Endurance Test Apparatus iron is placed on the three metallic supports and a thermocouple is attached at the midpoint of the sole plate. The iron is then operated at 1.5 times the maximum rated input. In case of thermostatic iron, the thermostat is set so that an average temperature of about 200°c is maintained under steady state conditions. The setting of the thermostat is fixed in an appropriate way so that the settings do not change during the measurement. For irons without thermostat or self resetting thermal cutouts, the temperature of the sole plate shall be maintained between 205°c and 260°c by suitable cooling means such as jet of air on a cooling plate.