Extending the Service Life of a Constant Temperature and Humidity Test Chamber

The constant temperature and humidity test chamber is a combination of high temperature, low temperature, and humid heat. Its repair difficulty is greater than other environmental testing equipment, and it is representative. Taking the constant temperature and humidity test chamber as an example, let's talk about its structure, some common faults, and troubleshooting methods.

The constant temperature and humidity test chamber is composed of a box, an air circulation system, a refrigeration system, a heating system, and a humidity control system. The air circulation system generally adopts a structure with adjustable air supply direction; There are two types of humidification systems: boiler humidification and surface evaporation; The cooling and dehumidification system adopts a refrigeration structure under air conditioning conditions; The heating system adopts two structures: electric fin heating and direct heating with electric furnace wire; The temperature and humidity testing method adopts the dry and wet bulb testing method, as well as the direct measurement method using humidity sensors; The control and display operation interface adopts methods such as temperature and humidity separation, independent control, and temperature and humidity combination controller.

Some common faults and troubleshooting methods of constant temperature and humidity test chambers. In high temperature tests, if the temperature change cannot reach the test temperature value, the electrical system can be checked and the faults can be eliminated one by one. If the temperature rises very slowly, check the air circulation system to see whether the regulating baffle of air circulation is opened normally. Otherwise, check whether the motor of air circulation is running normally. If the temperature overshoot is severe, it is necessary to adjust the PID setting parameters. If the temperature rises directly and there is over temperature protection, then if the controller malfunctions, the control instrument must be replaced.

If the low temperature does not meet the test indicators, it is necessary to observe the temperature changes. Whether the temperature drops slowly or there is a trend of temperature recovery after reaching a certain value, the former needs to check whether the studio is dried before conducting the low temperature test. After keeping the studio dry, the test samples are placed in the studio before conducting the test. If there are too many test samples placed in the studio, the air in the studio cannot be fully circulated, After eliminating the above reasons, it is necessary to consider whether it is a malfunction in the refrigeration system. Therefore, the rotor pump needs to be repaired by professional personnel from the manufacturer. The latter phenomenon is caused by the poor operating environment of the equipment, and the environmental temperature and location of the equipment placement (distance from the back of the box to the wall) must meet the requirements (as specified in the equipment operation instructions).

In the damp heat test, the actual humidity will reach 100% or the actual humidity is significantly different from the target humidity, and the value is much lower. The former phenomenon: it may be caused by the drying of the gauze on the wet bulb sensor. It is necessary to check whether the water tank of the wet bulb 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 wet bulb gauze may become hard due to prolonged use or the purity of the water supply, making it unable to absorb moisture and dry. Simply replacing or cleaning the gauze can eliminate the above phenomenon. 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 of the humidification boiler water level is normal, and whether the water level in the humidification boiler is normal. If everything above is normal, then it is necessary to check the electrical control system, which requires professional maintenance personnel for maintenance.

When the equipment suddenly malfunctions during the test operation, the corresponding fault display prompt and sound alarm prompt appear on the control instrument. Operators can quickly check which type of fault belongs to in the chapter on troubleshooting during equipment operation and use, and then ask professional personnel to quickly troubleshoot to ensure the normal operation of the test. Other environmental testing equipment may have other phenomena during use, so it is necessary to analyze and eliminate specific phenomena.