Why the homogeneity of the high and low temperature test chamber is not up to the standard

High and low temperature test chamber is a commonly used experimental equipment, which is suitable for high temperature and low temperature reliability test of industrial products. It is widely used in electronic electrician, automobile motorcycle, aerospace and other fields. In the course of use, high and low temperature test chambers will appear to have problems of non-compliance. What causes this? Here are the reasons why the homogeneity of high and low temperature test chambers is not met.

Thermal radiation: design problems lead to difficult to achieve a uniform symmetrical structure in the internal structure, space design, and the asymmetric structure will inevitably lead to internal temperature uniformity deviation, this level is mainly reflected in the sheet metal design and sheet metal processing Aspects, such as: the design of the air duct, the location of the heat pipe, the size of the fan power and other reasons.

Sealing: The sealing of the cabinet and the door is not strict, for example: the sealing strip is not custom-made with seams, the door leaks, etc., thereby affecting the temperature uniformity of the working space.

The rationality of sample selection and placement for high and low temperature test chambers: if the test object volume is too large, or the test object is placed in the work chamber of the high and low temperature test chamber, the position or mode is not suitable, so that the convection in the air is blocked, and it will also produce Large deviations in temperature uniformity. For example, putting the test product on the side of a wind tunnel seriously affects the circulation of the wind, and of course, the temperature uniformity will be greatly affected.

Because the inner wall structure is different, the temperature of the inner wall will also be non-uniform, thereby affecting the thermal convection within the working chamber to cause deviation of the internal temperature uniformity.

Thermal load: if the test sample in the working chamber of the high and low temperature test chamber is sufficiently large enough to affect the internal thermal convection, it will inevitably affect the uniformity of the internal temperature to a certain extent. For example, if the LED lighting product is placed, the product itself emits heat and becomes hot. Load, then there is a great influence on the temperature uniformity.

Heat transfer: Since the heat transfer coefficient of the six sides of the box wall is different from that of the top and bottom, left, right, top, bottom, left and right sides, some holes, holes, test holes, etc. lead to local heat dissipation and heat transfer, making the temperature of the box non-uniform, so that the box wall width The convection heat transfer is also non-uniform, affecting the temperature uniformity.