Environmental testing equipment variety, but the use of environmental testing equipment most widely used for high temperature, low temperature, damp heat test box, which is a popular collection of high temperature, low temperature, damp heat as one of the test box - test box with constant temperature and humidity, it is difficult to repair other environmental testing equipment, and representative. The following talks about the structure of constant temperature and humidity test box and some common faults and troubleshooting methods.
(A) The common structure of temperature and humidity test chamber
Test personnel in addition to correct according to the rules of operation, should also have an understanding of its structure. Cold and hot impact testing machine consists of box, air circulation system, refrigeration system, heating system and humidity control system. Air circulation system generally adopts the structure of adjustable wind direction; humidification system using boiler humidification and surface evaporation two; cooling and dehumidifying system using air conditioning refrigeration structure; heating system using direct heating electric heating furnace of wire and fin structure of two kinds of test methods; humidity by psychrometer temperature test method, also useful for direct measurement of humidity sensor; control and display interface with temperature and humidity independent temperature and humidity controller combination etc..
(B) Temperature and humidity test chamber of some common failures and troubleshooting:
1. Test at high temperature, such as temperature change is not up to the test temperature, can check the electrical system troubleshooting, one by one. If the temperature rises slowly, the wind circulation system should be checked to see if the wind regulating plate is normal, otherwise, check whether the motor operated by the wind circulation is normal or not. If the temperature overshoot is severe, the setting parameter of PID should be set. If the temperature rises directly, over temperature protection, then the controller is out of order, the control instrument must be replaced.
2. Test equipment in the operation process, control instruments appear on the corresponding fault display and voice prompt alarm. Operators can control the operation of the use of the equipment in the troubleshooting chapter, which kind of fault is quickly checked, you can ask professionals to quickly troubleshoot, in order to ensure the normal test. Other environmental test equipment in use
3. Low temperature is not up to the test index, then you have to observe the change of temperature, the temperature drop is very slow, or temperature to a certain value after the temperature rise, the former will check whether low temperature drying studio before the test, the studio remained dry before the test sample in the studio to do the test, the test sample is placed in the studio too much, the wind can not in studio full circle, excluding the above reasons, it is necessary to consider whether the fault is in the refrigeration system, so as to invite manufacturers of professional personnel for maintenance. The latter is caused by the poor use of the equipment, the environmental temperature placed in the equipment, placed position (the distance between the box and the wall) to meet the requirements (in the equipment operation instructions are specified).
4. in the damp heat test, the actual humidity will reach 100% or the actual humidity and humidity goal difference, low values of a lot, the former phenomenon: the wet bulb on the sensor may be caused by dry gauze to check, the wet bulb sensor in a tank is water shortage, water level in the water tank is automatically controlled a water level controller, water level controller system check whether normal water supply, the water level controller is working properly. Another possibility is that the wet bulb gauze due to the use of a long time, or water purity, the gauze hardens, the gauze can not absorb moisture and dry, as long as the replacement or cleaning gauze can be eliminated by the above phenomenon. The latter phenomenon is mainly the humidification system does not work, check the water supply system humidification system, if there is a water supply system, water level control of boiler water level control humidification is normal, the water level in the boiler is normal. If all of the above is normal, then check the electrical control system, which requires professional maintenance personnel for repair.
5. low temperature is not up to the test index, then you have to observe the change of temperature, the temperature drop is very slow, or temperature to a certain value after the temperature rise, the former will check whether low temperature drying studio before the test, the studio remained dry before the test sample in the studio to do the test, the test sample is placed in the studio too much, the wind can not in studio full circle, excluding the above reasons, it is necessary to consider whether the fault is in the refrigeration system, so as to invite manufacturers of professional personnel for maintenance.
The latter phenomenon is the use of equipment caused by the environment is not good, the equipment placed the ambient temperature, the location (distance from the wall of the box body to meet the requirements (after) are specified in the equipment operation instructions).
Environmental testing equipment and regular maintenance, condenser cooling system for moving parts should be cleaned regularly, according to the manual lubrication, electric control system and regular maintenance checks and so on, these work is essential.