The working principle and structural characteristics of the constant temperature and humidity test chamber

Constant temperature and humidity test box is also called constant temperature and humidity test machine, constant temperature and humidity test box, programmable humidity and heat alternating test box, constant temperature machine or constant temperature and humidity bo.
This material is heat-resistant, cold-resistant, dry-resistant and moisture-resistan.
It is suitable for testing the quality of electronics, electrical appliances, mobile phones, communications, instruments, vehicles, plastic products, metals, food, chemicals, building materials, medical care, aerospace and other product.
The constant temperature and humidity test box can be divided into "desktop" and "vertical.
The main difference is that the temperature and humidity that can be achieved are different, and the resulting temperature will also be differen.
The vertical type can be used for low temperature and drying below normal temperatur.
, The desktop can only do the temperature and high humidity above room temperatur.
Application field: suitable for quality testing of electronics, electrical appliances, mobile phones, communications, instruments, vehicles, plastic products, metals, food, chemicals, building materials, medical, aerospace and other product.
Working principle: The constant temperature and humidity test box consists of two parts: temperature regulation (heating, cooling) and humidificatio.
Through the rotating fan installed on the top of the box, the air is discharged into the box to realize gas circulation and balance the temperature and humidity in the bo.
The data collected by the built-in temperature and humidity sensor in the box is transmitted to the temperature and humidity controller (micro Information processor) to edit and process, and issue temperature and humidity control instructions, which are completed by the air heating unit, the condenser tube and the heating and evaporation unit in the water tan.
The temperature adjustment of the constant temperature and humidity box is to collect data through the built-in temperature sensor in the box, adjust the temperature controller (micro information processor), and connect the air heating unit to increase the temperature or adjust the refrigeration solenoid valve to reduce the temperature inside the box, so as to reduce the temperature inside the bo.
to the temperature required for contro.
The humidity adjustment of the constant temperature and humidity box is to collect data through the built-in humidity sensor in the body, adjust the humidity controller (micro information processor), connect the heating element of the water tank, and evaporate the water in the water tank to increase the humidity in the box or adjust the refrigeratio.
Solenoid valve to achieve dehumidification to achieve the required humidity contro.
A constant-humidity incubator refers to a test box that can apply temperature and humidity stress at the same tim.
With the needs of the development of Chinese industrial products, in recent years, China has introduced a large number of test systems from abroad, which have played an important role in the development and finalization of Chinese industrial product.
Many problems have occurred, and problems cannot be solved in time, which greatly prolongs the test period and affects the development of product.
The reason for these phenomena is the lack of understanding of the working principle of the comprehensive tes.
To this end, we briefly expounded the basic working principle of the test box, and introduced how to analyze and judge the failure of the comprehensive test box test equipmen.
The constant temperature and humidity box is composed of a refrigeration system, a heating system, a control system, a temperature system, an air circulation system, and a sensor syste.
The above systems belong to two major aspects: electrical and mechanical refrigeratio.
Structural features: In terms of box structure, the constant temperature and humidity test box is formed by CNC machine tools, with beautiful and novel appearance, and adopts non-reaction handles, which is easy to operat.
The studio is made of imported high-grade stainless steel with mirror panel, and the outer tank of the box is sprayed with A3 steel plat.
The ultra-fine insulation cotton is filled between the outside of the box and the inner tank, which has a good temperature insulation effect and effectively reduces the temperature fluctuation rate in the test bo.
In addition, the anti-aging silicone rubber sealing strip is tightly sealed, so that the box has no fog leakag.
produc.
Due to the harsh environment in the test box, in order to observe the situation in the test box clearly, Wuhan Shangshi chooses multi-layer tempered glass for the observation window, and sets up separate lighting lamps and fog brushes in the observation window to maintain a good observation fiel.
, monitor the test situation at any tim.
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 recorders, printers and computer.

Control characteristics: The control system of the test box can be said to be the heart of the entire equipment, in charge of cooling, heating, humidity control, circulation, and contro.
In terms of refrigeration, the compressor is imported from German.
The refrigeration system consists of a high temperature part and a low temperature part, each part is a relatively independent refrigeration syste.
The evaporation of the refrigerant in the high temperature part absorbs the heat of the refrigerant from the low temperature part and evaporates; the evaporation of the refrigerant in the low temperature part absorbs heat from the object to be cooled (air in the test machine) to obtain the cooling capacit.
The high temperature part and the low temperature part are connected by an evaporative condenser, which is both the condenser of the high temperature part and the condenser of the low temperature par.
The heating system adopts a completely independent nickel-chromium alloy electric heating type, with high resistivity, small resistance temperature coefficient, small deformation at high temperature and not easy to embrittle, its own heating temperature can reach 1000 ~ 1500 ℃, long service lif.
Humidification is the most important part of the constant temperature and humidity test box which is different from the high and low temperature test bo.
The constant temperature and humidity test box adopts an external isolation type, all stainless steel boiler type shallow surface evaporative humidifie.
The dehumidification method adopts mechanical refrigeration and dehumidification, which cools the air to below the dew point temperature, so that the water vapor greater than the saturated moisture content condenses and precipitates, thus reducing the humidit.
Air supply circulation system: The air circulation system consists of a temperature-resistant and low-noise air-conditioning motor and a multi-blade centrifugal wind whee.
It provides the circulation of air in the test machin.
The control system is the core of the comprehensive test box, which determines the heating rate, precision and other important indicators of the test machin.
Most of the controllers of the testing machine use PID control, and a small number of them use a combination of PID and fuzzy contro.

Because the control system basically belongs to the category of software, and this part generally does not have problems during us.
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