IEC 60068-2-66 is an environmental test standard developed by the International Electrotechnical Commission. It specifies the test method under constant heat and humidity (unsaturated pressurized steam) conditions. It is mainly used to evaluate the resistance of small electrical products (especially non-hermetic sealing components) to the effects of heat and humidity deterioration. The standard provides an accelerated test procedure to quickly evaluate the performance changes of products under harsh conditions by simulating high Humidity and pressurized steam environments. The test results can be used to predict the Reliability of the product in actual use, but do not involve external effects such as corrosion or deformation.