Maintenance method of hot and cold impact testing machine

There are many types of environmental testing equipment, but the most widely used environmental testing equipment is high temperature, low temperature, and humid heat test boxes. Nowadays, it is more popular to combine high temperature, low temperature, and humid heat test boxes-cold and hot impact test machines, and its repair The difficulty is greater than that of other environmental testing equipment and is representative. The following is an example of a cold and hot shock test machine, to talk about the structure of the cold and hot shock test machine and some common faults and troubleshooting methods.
A) The construction testers of the common cold and hot impact testing machines should not only operate in accordance with the operating procedures correctly, but also understand their structure. The cold and hot impact testing machine is composed of a cabinet, an air circulation system, a refrigeration system, a heating system and a humidity control system. The air circulation system generally adopts a structure that can adjust the direction of air supply; the humidification system has two types: boiler humidification and surface evaporation; the cooling and dehumidification system uses the air-conditioning working structure cooling structure; the heating system uses electric heating fin heating and electric furnace wire direct heating Two kinds of structure; temperature and humidity test method adopts dry and wet bulb test method, and also has direct measurement method with humidity sensor; control and display operation interface adopt temperature and humidity separate and temperature and humidity combined controller and other methods.
(2) Some common faults and troubleshooting methods of cold and hot impact testing machine:

1. In the high temperature test, if the temperature change does not reach the test temperature value, you can check the electrical system to eliminate the fault one by one. If the temperature rises very slowly, it is necessary to check the wind circulation system to see if the adjustment baffle of the wind circulation is opened normally, otherwise, check whether the motor of the wind circulation is operating normally. If the temperature overshoot is severe, then the PID setting parameters need to be adjusted. If the temperature rises directly and the over-temperature protection, then the controller fails, the control instrument must be replaced.

2. The low temperature can not reach the test index, then you should observe the temperature change, whether the temperature drops slowly, or the temperature has a tendency to rise after the temperature reaches a certain value, the former should check whether the temperature Drying in the studio, keep the studio dry, and then put the test samples into the work room for testing. Whether the test samples in the work room are placed too much, the wind in the work room cannot be fully circulated. It is necessary to consider whether it is a fault in the refrigeration system. In this case, the professional personnel of the manufacturer must be repaired. The latter phenomenon is caused by the poor use environment of the equipment. The ambient temperature of the equipment and the location (the distance between the back of the box and the wall) must meet the requirements (as specified in the operation instructions of the equipment).

3. In the humid heat test, the actual humidity will reach 100% or the actual humidity is very different from the target humidity, the value is much lower, the former phenomenon: it may be caused by the dry gauze on the wet ball sensor, then check the humidity Whether the water tank of the ball sensor is short of water, the water level in the water tank is automatically controlled by a water level controller, check whether the water supply system of the water level controller is normal, and whether the water level controller works normally. Another possibility is that the wet ball gauze will harden the gauze due to the long use time or the purity of the water supply, so that the gauze can not absorb the water and dry. Just replace or clean the gauze to eliminate the above phenomenon. The latter phenomenon is mainly because the humidification system does not work, check the water supply system of the humidification system, whether there is a certain amount of water in the water supply system, whether the water level control to control the water level of the humidification boiler is normal, and whether the water level in the humidification boiler is normal. If all of the above is normal, then check the electrical control system, which requires professional maintenance personnel to carry out maintenance.

4. When the equipment suddenly fails during the test operation, the corresponding fault display prompt and an audible alarm prompt appear on the control instrument. The operator can quickly check which type of fault belongs to the chapter of troubleshooting in the operation and use of the device, and then you can ask a professional to quickly troubleshoot to ensure that the test is carried out normally. There will be other phenomena in the use of other environmental test equipment, then specific phenomena, specific analysis and elimination are required.

The environmental test equipment should also be regularly maintained, the condenser of the refrigeration system should be cleaned regularly, the moving parts should be lubricated and lubricated according to the instructions, and the electrical control system should be regularly maintained and inspected. These tasks are essential.