Constant temperature and humidity test equipment maintenance

The current status of temperature and humidity environmental test equipment, the correct use of hot and humid environmental test equipment, and the maintenance of high and low temperature environmental test equipment are described. The purpose is to help the majority of environmental testers have a preliminary understanding of the correct use of environmental test equipment such as high and low temperature test equipment and damp heat test equipment. There are many types of environmental test equipment, but the most widely used environmental test equipment is the current status of temperature and humidity environmental test equipment, the correct use of hot and humid environment test equipment, and the maintenance of high and low temperature environmental test equipment. The purpose is to help the majority of environmental testers have a preliminary understanding of the correct use of environmental test equipment such as high and low temperature test equipment and damp heat test equipment. There are many types of environmental test equipment, but the most widely used environmental test equipment are high temperature test equipment, low temperature constant temperature test equipment, damp heat test equipment, and programmable constant temperature and humidity test equipment. Nowadays, it is more popular to integrate high temperature, low temperature, and damp heat. The test equipment-high and low temperature damp heat test box (constant temperature and humidity test box), it is more difficult to repair than other environmental test equipment, and it is representative. Let's take the high and low temperature humidity test box (constant temperature and humidity test box) as an example to talk about the structure of the constant temperature and humidity test box and some common faults and troubleshooting methods. (1) The structure of the common high and low temperature damp heat test chamber. In addition to correctly operating the high and low temperature damp heat test box in accordance with the operating procedures, the test personnel should also have an understanding of the structure of the damp heat test box. The high and low temperature damp heat test chamber is composed of a test chamber, an air circulation system, a refrigeration system, a heating system and a humidity control system. The air circulation system generally adopts the structure with adjustable air supply direction; the humidification system has two types: boiler humidification and surface evaporation; the cooling and dehumidification system adopts air-conditioning refrigeration structure; the heating system adopts electric heating fin heating and electric furnace wire direct heating Two structures; the temperature and humidity test method adopts the dry and wet bulb test method, and the direct measurement method of the humidity sensor is also used; the control and display operation interface adopts the independent temperature and humidity and the temperature and humidity combined controller and other methods. (2) Some common faults and troubleshooting methods of the high and low temperature damp and heat test chamber: 1. In the high temperature test, if the temperature change does not reach the test temperature value, you can check the electrical system and eliminate the faults one by one. If the temperature rises very slowly, check the air circulation system to see if the adjustment baffle of the air circulation is open normally, otherwise, check if the motor of the air circulation is operating normally. If the temperature overshoot is severe, then you need to tune the PID setting parameters. If the temperature rises directly and the over-temperature protection is applied, then the controller fails and the control instrument must be replaced. 2. If the low temperature fails to reach the test index, then you have to 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 be checked to see if the temperature will be changed before the low temperature test. Drying in the studio. After keeping the studio dry, put the test samples in the studio and do the test again. Whether the test samples in the studio are placed too much so that the wind in the studio cannot be fully circulated. After removing the above reasons, It is necessary to consider whether it is a fault in the refrigeration system, so that it is necessary to ask the manufacturer's professional personnel to perform maintenance. The latter phenomenon is caused by the bad environment in which the equipment is used. The environment temperature and position (the distance between the back of the cabinet and the wall) of the equipment must meet the requirements (there are provisions in the operating instructions of the test equipment). 3. In the damp heat test, it appears that the actual humidity will reach 100% or the actual humidity is very different from the target humidity, and the value is much lower. The former phenomenon: it may be caused by the dryness of the gauze on the wet bulb 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 due to the long use time or the purity of the water supply, making the gauze unable to absorb water and dry. The above phenomenon can be eliminated by replacing or cleaning the gauze. The latter phenomenon is mainly that 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 for controlling the water level of the humidification boiler is normal, and whether the water level in the humidification boiler is normal. If everything above is normal, then check the electrical control system, which requires professional maintenance personnel to overhaul. 4. When the test equipment suddenly fails during the constant temperature test operation, the corresponding failure display prompt and audible alarm prompt will appear on the control instrument of the test box. The operator can quickly check which type of fault belongs to in the troubleshooting chapter of the operation and use of the equipment, and then ask professionals to quickly repair and troubleshoot to ensure the normal progress of the test.