One of the criteria for evaluating the performance of high-low Temperature Test Chambers is uniformity, but most manufacturers of high-low Temperature Test Chambers have insufficient uniformity control and cannot meet the needs of users for high precision, so today I will analyze the uniformity of high-low Temperature Test Chambers. The reasons for poor performance, how to control the uniformity of excellent high-low Temperature Test Chamber manufacturers.
1. Reasons for the low uniformity of the high-low Temperature Test Chamber
The structure of the high-low Temperature Test Chamber largely affects the temperature uniformity in the middle of the work. Since the structure is difficult to be completely symmetrical, it will adversely affect the temperature uniformity. The door is in front, and the air-conditioned room is behind the box, so you can go up and down. Obviously, this structure has good left-right symmetry, and it is easier to achieve uniform temperature on the left and right sides, but this structure is asymmetrical up and down, and the front and back are completely different, which has an uneven impact on the temperature. The temperature of the work space. However, if this single duct structure is properly designed and handled, practice has proved that the studio can use 0.1 to 300m³,
Due to the heat conduction of the box wall, heat loss such as heat leakage (high temperature box) or cold leakage (low temperature box) occurs. To compensate for heat loss, a temperature difference is required in the supply air. The air supply temperature of the high temperature box is higher than the working temperature inside the box, and the air supply temperature of the low temperature box is lower than the working temperature inside the box. Due to the inevitable temperature difference of the air supply, the temperature in the working room is uneven.
Due to the different heat transfer coefficients on the six sides of the high-low Temperature Test Chamber walls, some have threaded holes and other local heat transfer, which makes the temperature of the chamber wall uneven, makes the wall of the radiation convection heat exchange chamber uneven, and affects the uniformity of the temperature field.
The sealing of the box is not good, such as the door leaks, which affects the uniformity of the temperature field in the working space.
If the detection of temperature deviation needs to place the test sample in the working room, when the volume of the test product is too large, or the way or position of the test product is not suitable, the air convection is blocked, and a large temperature deviation will appear.
2. How to control the uniformity of the equipment in the high-low Temperature Test Chamber?
In terms of the precision control of the high-low Temperature Test Chamber, in order to accurately control the uniformity of the Test Chamber, the test adopts the hot air flow working method. A method of bypassing the high-temperature gaseous refrigerant to the low-pressure side of the system, thereby ensuring that the system always operates at a given minimum return gas pressure. Coupled with effective control means, the overall operation of the equipment has achieved a high degree of stability and uniformity.
