The Temperature deviation is the allowable range of the reference value. For example, the temperature deviation is 100 (+2) degrees. When controlling the temperature, the temperature of the box body is allowed to be 98-102 degrees.
The fluctuation value means that after setting the benchmark value, because the heat dissipation is not uniform, there will be a certain fluctuation in a short time, the range of fluctuation may be larger, for example, +5 degrees; that is, the temperature will fluctuate between 95-105 degrees.
1. Heating load
If enough experimental samples are placed in the operating room of temperature humidity test chamber to influence the overall heat convection inside, it will inevitably affect the uniformity of the internal temperature to a certain extent.
For example, when LED lighting commodities are placed, the commodities themselves have luminous heating, which becomes a heat load, then the uniformity of the temperature will have a great impact.
2. Heat Transfer
Because the heat transfer coefficients of the front and back sides of the chamber wall are different, some of them have perforation holes, detection holes, test holes and so on, which cause local heat dissipation and heat transfer, so that the temperature chamber is not uniform, and then the radiation convection heat transfer of the box wall is not uniform, affecting the temperature uniformity.
3. heating radiation
Design problems make it difficult to achieve a uniform symmetrical layout in the internal layout and space planning of the chamber, and the asymmetrical layout will inevitably lead to errors in the internal temperature uniformity. This level is mainly reflected in the sheet metal planning and sheet metal processing, such as the planning of air ducts, the location of heat pipes, the size of fan power and other reasons.
The sealing of chamber and door is not strict, such as non-customized seams of sealing strip, leakage of door, etc., and then affect the temperature uniformity of working space.
5. Rationality of sample selection and placement
If the volume of the experimental target is too large, or the orientation or method of the experimental target placed in the operating room of the high and low temperature experimental chamber is not appropriate, the air convection inside will be blocked, and the error of temperature uniformity will also occur. For example, putting the experimental commodity next to the wind channel seriously affects the circulation of the wind, of course, the uniformity of temperature will be greatly affected.