High and low temperature test chamberFrosting or freezing inside the box is a common problem during the simulation of temperature environment. This not only affects the performance of the test chamber and the accuracy of the test results, but may also shorten the service life of the equipment. Here are some methods to deal with frosting or icing inside the box.

1、 Analyze the causes of frost or ice formation

1. Abnormal humidity control:Excessive humidity inside the test chamber is one of the common causes of frosting or freezing. On the one hand, if there is a malfunction in the humidification system, such as continuous operation of the humidifier, it will cause excessive water vapor inside the box, which can easily condense into frost or ice in low temperature environments. On the other hand, the test sample itself emits water vapor. If it is not sufficiently dried before the test, it will also increase the humidity inside the box, leading to frost or ice formation.

2. Poor sealing performance:The sealing performance of the test chamber is crucial for preventing frost or ice formation. If the sealing strip of the box door is aged, deformed, or damaged, external humid and hot air will seep into the box. In the low-temperature stage, when these humid and hot air are cooled, water vapor will quickly condense on the walls of the box, sample racks, and other parts, forming frost or ice. In addition, other parts of the box, such as the observation window and pipeline interfaces, may not be tightly sealed, which may also cause external water vapor to enter.

3. Refrigeration system issues:Refrigeration system malfunction may cause frosting or icing inside the box. For example, if the surface temperature of the evaporator is too low, the evaporator should operate within a certain temperature range under normal circumstances. If its temperature is lower than the dew point temperature, the water vapor inside the box will condense into frost or ice on the surface of the evaporator. In addition, refrigerant leakage can lead to a decrease in refrigeration capacity. In order to achieve the set low temperature, the refrigeration system may overcooled, resulting in frost or ice formation inside the box.

2、 Resolve frosting or icing issues

1. Defrosting and defrosting operation:When frost or ice is found inside the box, the first step is to perform defrosting and defrosting operations. To avoid damaging the test chamber, the correct method should be used. For slight frosting, the temperature of the test chamber can be adjusted to room temperature first, allowing the frost or ice to naturally melt, and then dry the moisture inside the chamber with a clean soft cloth. If frost or ice is severe, the power supply of the test chamber can be cut off, the chamber door can be opened, and after most of the frost or ice has melted, the remaining part can be gently scraped off with a plastic scraper. Be careful not to use sharp tools to avoid scratching the chamber. For frost or ice on the surface of the evaporator, a hair dryer or other equipment can be used to blow it at a low temperature to accelerate melting, and the moisture should be cleaned up in a timely manner after melting.

2. Repair humidity control malfunction:If frosting or freezing occurs due to abnormal humidity control, it is necessary to troubleshoot and repair the relevant faults. Check the humidification system to see if the humidifier is working properly. If the humidifier components are damaged, such as a faulty atomizer or water level sensor, they should be replaced promptly. For the problem of water vapor emission from test samples, it is necessary to ensure that the samples are fully dried before the test. Drying, natural air drying, and other methods can be used. At the same time, the humidity inside the test chamber should be reasonably controlled, and the humidity parameters should be accurately set according to the test requirements. The humidity sensor should be calibrated regularly to ensure the accuracy of humidity control.

3. Improve sealing performance:To address the issue of poor sealing performance, it is necessary to conduct a comprehensive inspection of the sealing parts of the test chamber. If the sealing strip of the box door is aged or damaged, a new sealing strip needs to be replaced. When replacing, ensure that the rubber strip is tightly attached to the box door, and apply an appropriate amount of sealant on the surface of the rubber strip to enhance the sealing effect. Check the sealing condition around the observation window and at the pipeline interface. If there are gaps, use sealant to seal them. Regularly test the sealing performance of the test chamber, such as using smoke testing method to release smoke inside the chamber and observe whether there is smoke leakage, in order to promptly detect and solve sealing problems.

4. Maintenance of refrigeration system:If there is suspicion of a problem with the refrigeration system, professional maintenance personnel should be contacted for repair. Maintenance personnel need to check the working status of the evaporator, such as whether it is blocked, deformed, etc. If there are any problems, it needs to be cleaned or replaced. At the same time, check the pressure and content of the refrigerant to determine if there is any leakage. If the refrigerant leaks, it is necessary to locate the leak point and repair it, and then replenish an appropriate amount of refrigerant. During the maintenance process, strictly follow the maintenance specifications of the refrigeration system to ensure its normal operation.

High and low temperature test chamberThe problem of frosting or icing inside the test chamber should be taken seriously, and the causes should be analyzed in a timely manner and corresponding solutions should be taken to ensure the normal operation of the test chamber and the reliability of the test results. In daily use, regular maintenance and upkeep of the test chamber should also be carried out to prevent frost or icing problems.