1 Introduction 1.1 Reference ambient conditions 1.2 Devices without heat-dissipation 1.3 Devices with heat-dissipation 1.4 Ambient temperature 1.5 Surface temperatures2 Reasons for the differing test procedures 2.1 Mechanisms of heat transfer3 Test chambers 3.1 General 3.2 Methods of achieving the required conditions in the test chamber4 Measurements 4.1 Temperature 4.2 Air velocity 4.3 Emissivity coefficient5 Precautions on tests 5.1 Overstress 5.2 Testing precautionsAppendix A Effects of size of chamber on surface temperature of a specimen when no forced air circulation is usedAppendix B Effect of airflow on chamber conditions and on surface temperatures of test specimensAppendix C Effect of specimen emissivity coefficient in temperature riseAppendix D Effect of wire termination dimensions and material on surface temperature of a componentAppendix E Heat transfer calculations and nomogramsAppendix F Thermal conductivities of common materialsAppendix G Measurement of temperatureAppendix H Measurement of air velocityAppendix J Measurement of emissivity coefficientAppendix K general block diagram, cold and dry heat tests