In the process of product development and quality control, simulating product performance under extreme environmental conditions is a crucial task. Thermal shock test is a common method used to evaluate the performance stability of materials or products under rapid temperature changes. As an advanced testing equipment, the Three box-type Thermal Shock Test Chamber has been widely used in aerospace, electronics, automobile manufacturing and other industries.
This article takes an in-depth look at its operating procedures, working principles, common problems, and basic factors of daily maintenance.
1. Operation process of three box-type thermal shock test chamber
The three box-type thermal shock test chamber usually consists of a high temperature chamber, a low temperature chamber and a specimen transfer chamber. The operation process includes heating the specimen to the set temperature in the high temperature chamber, then moving it to the specimen transfer chamber, and then quickly transferring the specimen in the transfer chamber to the low temperature chamber to quickly cool it to the set temperature. After the test is completed, the specimen is heated again to the set temperature in the low temperature chamber, then moved back to the specimen transfer chamber, and finally taken out of the transfer chamber.
2. Working principle of three box-type thermal shock test chamber
(1) Low-temperature storage room: The temperature state in the box is determined by the working state of the heater, evaporator and fan in the air duct. After the refrigerant flows out through the expansion valve throttling, it enters the evaporator in the working room, absorbs the heat in the working room and vaporizes, so that the temperature of the working room is reduced; the vaporized working fluid is sucked into the compressor and compressed into high-temperature, high-pressure gas, enters the condenser and is condensed into liquid, and then passes through the screening program, and finally passes through the expansion valve throttling, and then re-enters the evaporator in the working room to absorb heat and vaporize, and then is sucked into the compressor and compressed. This reciprocating cycle works to reduce the temperature of the working room to the set temperature requirement.
(2) High-temperature storage room: The central controller detects the instantaneous signal from the temperature sensing element, compares it with the set temperature signal, obtains the comparison signal, and controls the on or off time ratio of the solid-state relay by the output signal of the instrument PID logic circuit to adjust the output power of the heater, thereby achieving the purpose of automatic temperature control.
(3) Shock temperature test room: The high and low temperature gas valves are automatically controlled by the instrument to switch between the low temperature or high temperature storage room, forming a closed-loop air circulation system with the high temperature box or low temperature box respectively, and quickly reaching the target temperature of the test.
The temperature state in the test chamber is determined by the working state of the heater, evaporator, and fan in the air duct. The test chamber adopts forced axial flow "dispersive" circulating air to work, which can greatly improve the fluctuation and uniformity of equipment operation.
3. Common fault solutions for three box-type thermal shock test chamber
During use, some common faults will be encountered, which will affect the test results. How to solve them? Here are some common faults and solutions.
(1) The low temperature box or high temperature box cannot reach the set temperature
Solution: First check whether there is dirt in the machine, clean the dirt in the fan and heat exchanger, or check whether there is unstable power supply voltage or too low power supply. If the above faults are determined not to exist, you need to replace the faulty parts or contact maintenance personnel for repair.
(2) The door of the test chamber cannot be closed normally
Solution: Check whether the door rubber pad is worn or loose. If worn or loose, replace or adjust the door rubber pad in time.
(3) There is a peculiar smell in the box
Solution: The peculiar smell in the box may be caused by the burning of machine parts or other pollution factors. First, you need to eliminate the above faults, then clean the box, and completely eliminate the peculiar smell.
(4) The program cannot run
Solution: First check whether the power is on and whether the program settings are correct. If there are errors, adjust them or reset the program.
In short, three box-type thermal shock test chamber will encounter some faults during use. By promptly discovering and solving the faults, the normal operation of the testing machine can be guaranteed, providing effective testing support for various industries.
4. The maintenance of the three-chamber hot and cold shock test chamber mainly includes the following aspects:
Cleaning: Regularly clean the inside and outside of the test chamber, especially the key parts such as temperature sensors, heaters, fans, etc., to prevent dust and debris from affecting the normal operation of the equipment.
Inspection: Regularly check the operating status of the equipment, including key components such as temperature, humidity, compressors, etc., to ensure the normal operation of the equipment.
Lubrication: Regularly lubricate the parts that need lubrication, such as fan bearings, screws, etc., to keep them running normally.
Corrosion protection: Avoid contact with chemicals that are corrosive to metals to prevent corrosion of the equipment.
Power supply maintenance: Regularly check whether the power cord is damaged and the plug is loose to ensure normal power supply.
Software maintenance: Keep the control software updated to obtain better control performance and fault diagnosis functions.
Record maintenance: Keep records after each maintenance to track the maintenance history of the equipment and find potential problems in time.
Safety prevention: Ensure that the test chamber will not cause harm to the operator during use, such as setting up safety shields, warning signs, etc.
Environmental control: Keep the environment around the test chamber clean to prevent dust, debris, etc. from affecting the normal operation of the test chamber. At the same time, the ambient temperature and humidity around the test chamber should be kept within the specified range to ensure the accuracy of the test results.
Regular calibration: The test chamber should be calibrated regularly to ensure the accuracy and reliability of its test results. The calibration cycle is generally no more than one year.
