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 reference value, due to uneven heat dissipation, there will be certain fluctuations in a short period of time, and the fluctuation range may be large, such as +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 the temperature and humidity test room to affect the overall heat convection inside, it will inevitably affect the uniformity of the internal temperature to a certain extent.
For example, when placing LED lighting products, the products themselves have luminous heating, which becomes a heat load, and the uniformity of temperature will have a great impact.
2. Heat transfer
Since the heat transfer coefficients of the front and back of the chamber wall are different, some of them have perforations, detection holes, test holes, etc., which will cause local heat dissipation and heat transfer, so the temperature chamber is not uniform, and the radiation of the chamber wall will affect the Uneven heat transfer affects temperature uniformity.
3. The heat radiation
design problem makes it difficult to obtain a uniform symmetrical layout in indoor layout and space planning, and an asymmetrical layout will inevitably lead to errors in internal temperature uniformity. This level is mainly reflected in the sheet metal plan and sheet metal processing, such as the plan of the air duct, the position of the heat pipe, the size of the fan power and other reasons.
4.
Airtightness The airtightness of the door is not strict, such as the seam of the sealing strip is not fixed, the door leaks, etc., which will affect the temperature uniformity of the working space.
5. The rationality of sample selection and placement
If the volume of the experimental object is too large, or the direction or method of the experimental object is not suitable for placement in the operating room of the high temperature and low temperature laboratory, the internal air convection is blocked, and the temperature will also occur Uniformity error. For example, placing the experimental product near the air duct will seriously affect the circulation of the wind, and of course, the uniformity of the temperature will also be greatly affected.
