Equipment characteristics of constant temperature and humidity chamber
In terms of the structure of the box, the constant temperature and humidity test chamber is formed by CNC machine tool, which is beautiful and novel in appearance, and adopts no reaction handle, which is easy to operate. The studio is made of imported mirror panel high-grade stainless steel, and the outer casing of the box is sprayed with A3 steel plate. The ultra-fine insulation cotton is filled between the outside of the box and the inner tank, the temperature isolation effect is very good, the temperature fluctuation rate in the test box is effectively reduced, and the tight sealing of the anti-aging silicone rubber sealing strip is combined to make the box have no fog leakage phenomenon. produce. Due to the harsh environment in the test chamber, in order to observe the situation inside the test chamber, the observation window is made of multi-layer tempered glass, and separate illumination lamps and fog brushes are set in the observation window to maintain a good observation field and monitor at any time. Test situation. Of course, in order to collect test data, the box is specially equipped with a test hole with a diameter of 50mm, which can be connected to a recorder, a printer and a computer.
Control features
The control system of the test chamber can be said to be the heart of the entire equipment, and it is in charge of cooling, heating, humidity control, circulation, control and so on.
In terms of refrigeration, the compressor is a compressor imported from Germany. The refrigeration system consists of a high temperature section and a low temperature section, each section being a relatively independent refrigeration system. The evaporation of the refrigerant in the high temperature portion absorbs heat from the refrigerant in the low temperature portion and vaporizes; the evaporation of the refrigerant in the low temperature portion absorbs heat from the object to be cooled (air in the test machine) to obtain the amount of cold. The high temperature portion and the low temperature portion are connected by an evaporating condenser which is both a condenser at a high temperature portion and a condenser at a low temperature portion.
The heating system adopts completely independent nickel-chromium alloy electric heating type, which has large resistivity and small temperature coefficient of resistance. It is small in deformation at high temperature and is not easy to embrittle. The heating temperature can reach 1000-1500 °C and the service life is long.
Humidification is the most important part of the constant temperature and humidity test chamber different from the high and low temperature test chamber. The constant temperature and humidity test chamber adopts an external isolation type, all stainless steel boiler type shallow surface evaporation humidifier. The dehumidification method uses mechanical refrigeration dehumidification to cool the air below the dew point temperature, so that the water vapor larger than the saturated moisture content is condensed and precipitated, thus reducing the humidity.
Air supply circulation system: The air circulation system consists of a temperature-resistant low-noise air-conditioning motor and a multi-leaf centrifugal wind wheel. It provides a circulation of air inside the test machine.
The control system is the core of the comprehensive test chamber, which determines important parameters such as the heating rate and accuracy of the test machine. Most of the controllers of the test machine use PID control, and a small number of control modes that combine PID and fuzzy control. Since the control system is basically in the category of software, and this part is in use, there is generally no problem.