GB/T 38924.7-2020 specifies the test conditions, equipment and instruments, test procedures, and result evaluation for damp heat testing of civil light and small unmanned aircraft systems (including aircraft and ground stations) with a takeoff weight ranging from 0.25 kg to 150 kg. It applies to related equipment that needs to undergo damp heat environmental conditions. The test is divided into three stages: temperature rise, high temperature and high humidity, and temperature decrease. The high temperature can be selected from 40°C to 65°C, with a relative humidity of ≥85%, and each cycle lasts 24 hours. Instruments such as damp heat test chambers, temperature and humidity sensors, and dry and wet bulb thermometers are used to control the temperature, humidity, and wind speed inside the chamber, ensuring that the environmental parameters around the equipment under test meet the tolerance requirements. This is done to evaluate the equipment's ability to withstand humid atmospheric conditions.