Basic knowledge of high and low temperature test chamber

At this stage, various manufacturers of natural environment experimental equipment in various countries around the world show the performance parameters of the variable temperature speed as the average speed of the whole line. The temperature rate of the linear elevator refers to the temperature change speed that can be ensured within an arbitrary time range of every 5 minutes. In fact, for the rapid temperature rise low-temperature test chamber, it is more difficult and important to ensure the temperature rate of the linear elevator. Within a period of 5 minutes after the temperature reduction section, the temperature reduction rate of the test chamber can be achieved. . Therefore, it is good for the high and low temperature test chamber to have two main parameters: the average speed of the whole elevator and the linear speed of the elevator (average rate every 5 minutes). Generally speaking, the temperature rate of the linear elevator (average rate every 5 minutes) is the whole line The average temperature rate of the elevator is 1/2.
　　 Reasons for temperature asymmetry in high and low temperature test chamber
　　 1. Inside the test box, there are enough test specimens to harm the convective heat transfer of all personnel inside, which will harm the internal temperature's symmetry at a certain level.
　　 2. Different internal structure of high and low temperature test box will cause deviation of internal temperature uniformity. Such as the overall planning of the air duct, the placement direction of the heating tube, and the output power of the centrifugal fan are all harmful to the temperature uniformity of the box body.
　　3. Due to the difference in the internal cavity structure of the high and low temperature test chamber, the temperature of the internal cavity of the test chamber will also be uneven, which will endanger the convection heat transfer in the working room and produce deviations in the internal temperature symmetry.
4. Due to the different thermal conductivity of the six walls on the upper, lower, left and right sides of the box wall of the studio, some of them have wire mounting holes, inspection holes, test holes, etc., which cause part of the heat pipe to dissipate heat and conduct heat, which makes the temperature of the housing uneven, which in turn causes The radiation on the wall of the box is uneven to the heat transfer in a wide range, which is harmful to the temperature.
　　 5. The tightness of the shell and the door is not tightly closed, which will harm the temperature uniformity of the working room space.
　　 6. The volume of the test piece is too large, or the direction or method of placing the test piece in the working room of the high and low temperature test chamber is not suitable. If the convection of the air encounters resistance, there will also be a large deviation in temperature symmetry.