The structure design and hardware configuration of the constant humidity test chamber
Constant temperature and humidity test chamber mainly simulate the ability of products to withstand high and low temperatures and different humidity, which is our essential testing equipment. Good performance of the constant temperature and humidity test chamber requires a reasonable structural design and control circuit closely, in order to obtain a high degree of stability. The structural design of the test chamber should include the design of the test chamber, the chamber sealing design, and the mechanical structure of the box can achieve the reciprocal movement of the support design of the three major parts. Among them, the design of the mechanical structure of the box is the focus of the design, the purpose of the design is to make the test chamber test tube holder can achieve reciprocal movement back and forth so that the test sample full temperature and humidity to maintain uniformity.
The actual design process can be based on economic and other influencing factors to determine the final solution. The main requirements for the structure and process of constant temperature and humidity test chamber is: sealing performance to be good; insulation layer thermal conductivity is small, to ensure good temperature conductivity; the heating body has sufficient heat capacity; test chamber weight ≤ 20kg; temperature regulation range: room temperature 10 ℃ ~ 70 ℃. Only to meet these requirements, in order to reduce the starting heating power, heating power in the equilibrium state, heating time, and control temperature fluctuations within the chamber, so as to ensure that the test chamber has good performance.
For the constant temperature and humidity test chamber structure design needs to be based on the mechanical expected to achieve the functional requirements, the conception of all possible functional principles, to analyze and compare and according to the use of the requirements or process requirements, from which to choose both to meet the functional requirements, the process action and simple working principle. The above step is called functional principle design, which is the first step of the mechanical actuation system program design. To achieve the same functional requirements can choose many different working principles, the corresponding implementation system program is bound to be different. If you do not consider reversing, only consider the forward and backward feed process, the following methods can be used:
1, with constant temperature and humidity test chamber rack and pinion or sprocket chain drive, with reverse, smooth switch to control the motor forward and reverse.
2, with a plane cam linkage mechanism, can also realize the reciprocating motion of the mechanism.
3, with the eccentric wheel, can also realize the reciprocating motion of the mechanism.
4、Using crank slider mechanism.
A constant temperature and humidity test chamber controller description:
① controller model: 880 original imported touch screen controller.
② display mode: LCD liquid crystal display, true color interface, Chinese and English display.
③ control mode: program control or fixed value control are available.
④ Real-time monitoring (monitor the controller real-time data, signal point status, the actual output state)
⑤ curve recording function: control can store 600 days of historical data (24 hours of operation, record interval of 1min or more, temperature and humidity data recorded at the same time), and can playback the uploaded control within the historical data curve.
⑥The constant temperature and humidity test chamber is equipped with a USB port, which can directly drive the micro printer preview and print through the port (optional)
⑦Temperature and humidity control adopt P.I.D + S.S.R system with channel coordination control.
⑧ With the function of automatic calculation, the temperature and humidity change conditions can be corrected immediately, so that the temperature and humidity control is more accurate and stable.
Second, the main configuration of constant temperature and humidity test chamber:
① stainless steel electric heater, electric steam generation humidification mode.
② original French Tacon fully enclosed compressor composed of air-cooled complex refrigeration system, the full range of the use of the United States DuPont refrigerant R404A, R23; green non-polluting, high efficiency and environmental protection and reliable, does not hurt the human body.
③ Adopt high and low temperature resistant long shaft motor, with high and low-temperature resistant aluminum multi-wing impeller. With forced convection vertical diffusion circulation, to avoid dead space in the box, so that the distribution of temperature and humidity in the box is uniform and constant.