The national standard GB/T 2423.34-2024 environmental testing Part 2: Test methods, Test Z/AD: Temperature/Humidity combined cycle test specifies an environmental test method for evaluating the tolerant performance of component specimens under high temperature/humidity and low temperature conditions. This test method accelerates the determination of the performance change of samples under severe climate conditions by simulating periodic changes in temperature and Humidity. The standard describes the test conditions, severity, test procedures and test requirements in detail and is suitable for specimens that are not energized throughout the test process. The standard will be implemented on March 1, 2025, replacing GB/T 2423.34-2012, equivalent to the IEC 60068-2-38:2021 international standard.