constant temperature and humidity chamberalso calledConstant temperature and humidity testing machineEquipment used to test the performance of materials in various environments and to test the heat resistance, cold resistance, dry resistance, and moisture resistance of various materials. Suitable for quality testing of electronic, electrical, mobile phone, communication, instrument, vehicle, plastic products, metal, food, chemical, building materials, medical, aerospace and other products.

buyconstant temperature and humidity chamberThere are many factors to consider, and the first one to choose is the size of the box volume. To ensure that the surrounding environment of the tested product meets the environmental testing conditions specified in the testing specifications, the volume of the box needs to be at least 3-5 times the external volume of the tested product. There are several reasons for this:

1. According to the principle of heat conduction, the temperature of the airflow near the box wall is usually 2-3 ℃ different from the temperature at the center of the flow field, and may even reach 5 ℃ at high and low temperatures. The temperature of the box wall differs from the temperature of the flow field near the box wall by 2-3 ℃ (depending on the structure and material of the box wall). The greater the difference between the experimental temperature and the external atmospheric temperature, the greater the aforementioned temperature difference. Therefore, the space within a distance of 100-150mm from the box wall is unusable.

2. After the test piece is placed in the box, it occupies the airflow channel in the flow field. Narrowing the channel will affect the airflow velocity and accelerate the heat exchange between the airflow and the test piece, which is inconsistent with the reproducibility of environmental conditions. Because in relevant standards, it is stipulated that the air velocity around the test sample in the test chamber should not exceed 1.7m/s for temperature environment tests to prevent unrealistic heat conduction between the test sample and the surrounding atmosphere. When unloaded, the average wind speed in the test chamber is 0.6~0.8m and should not exceed 1m/s. When the required space and area ratio is met, the wind speed in the flow field may increase by (50~100)%, and the average maximum wind speed is (1.17) m/s, which meets the requirements of the standard. If the volume or windward cross-sectional area of the test piece is increased without restrictions during the experiment, the actual airflow speed during the test will exceed the maximum wind speed specified in the test standard, and the validity of the test results will be questioned.

3Humidity ChamberThe accuracy indicators of environmental parameters in the working chamber, such as temperature, humidity, salt spray settling rate, etc., are all measured under no-load conditions. Once the test piece is placed, it will have an impact on the uniformity of the environmental parameters in the working chamber of the test box. The larger the space occupied by the test piece, the more severe this impact will be. Experimental data shows that the temperature difference between the windward and leeward sides in the flow field can reach 3-8 ℃, and in severe cases, it can exceed 10 ℃. Therefore, it is necessary to meet this requirement as much as possible to ensure the uniformity of environmental parameters around the tested product.

The above points are for purchasingHumidity ChamberWhen choosing the volume of the box, it is necessary to consider various factors. If the test object is relatively special, more factors must be taken into account.