Why does the constant temperature and humidity test chamber frost under low temperature and low humidity conditions

Frost formation in the constant temperature and humidity test chamber during low-temperature and low humidity testing is usually caused by abnormalities in equipment status, operating procedures, or environmental factors. Although set to low humidity, local water vapor may still condense. ‌

Humidity control and environmental factors: Even if the humidity is set low, if the humidity sensor malfunctions or calibrates incorrectly, it may cause the actual humidity inside the box to be too high; In addition, frequent opening and closing of the box door or aging and damage of the sealing strip can allow moist air from the outside to seep in and condense into frost on low-temperature components. ‌

Abnormal temperature setting and refrigeration system: If the temperature is too low or the cooling is too fast, the water vapor will not be processed by the dehumidification system in time and frost will quickly form; Refrigeration system problems such as refrigerant leakage, decreased compressor performance, or dirty evaporator can cause the surface temperature of the evaporator to be too low, exacerbating frost formation. ‌

Equipment status and operating specifications: Air duct blockage, fan failure, or sample placement obstructing airflow can cause uneven distribution of cooling capacity and local frosting; Improper operation, such as opening the door without sufficient drying of the cabinet, or insufficient maintenance (such as failure of the drying filter), may also introduce moisture and cause freezing. ‌