As the demand for environmental testing continues to increase, as one of the main test chambers for temperature and humidity testing, the application of high and low temperature damp heat test chambers is also increasingly widespread. So, how to choose the right model is also one of the issues that the majority of users are more concerned about. The following information is comprehensively organized according to the specific practice of the Beijing Yashilin Sales Department and the Technology Department, combined with theory, for the reference of the users. .
First, the choice of volume
When the test product (components, components, parts or the whole machine) is placed in a high and low temperature and humidity environment box for testing, in order to ensure that the test product can meet the environmental test conditions specified in the test specifications, the working size of the test box and the outline of the product under test The following points should be followed between sizes:
1. The volume of the tested product (W × D × H) shall not exceed (20 ～ 35)% of the effective working space of the test chamber (20% is recommended). It is recommended to select no more than 10% for products that generate heat during the test.
2. The ratio of the windward cross-sectional area of ​​the tested product to the total area of ​​the test chamber studio on this cross-section is not greater than (35-50)% (35% is recommended).
3. The distance between the outer surface of the tested product and the wall of the test box should be at least 100-150mm (150mm is recommended).
Second, the choice of temperature range
At present, the temperature range of foreign test chambers is generally -73 ～ + 177 ℃. Most domestic manufacturers are generally -60 ~ +130 ℃, Beijing Yashilin R & D Department through technological innovation, the temperature range of high and low temperature test chamber is -80 ~ +180 ℃, the temperature range can usually meet most domestic military and civilian For the needs of product temperature testing, customers should select the temperature range according to their actual test requirements. Unless there are special needs, such as products installed near the engine and other heat sources, the upper temperature limit cannot be blindly increased. Because the higher the upper limit temperature, the greater the temperature difference between inside and outside the box, and the worse the uniformity of the flow field inside the box. On the other hand, the higher the upper limit temperature value, the higher the heat resistance requirement of the thermal insulation material (such as glass wool) in the wall sandwich. The higher the sealing requirements of the box, the higher the manufacturing cost of the box.
3. Selection of humidity range
The humidity index given by Beijing Yashilin High and Low Temperature Humidity and Heat Test Chamber is divided into 20 ～ 98% RH and 30 ～ 98% RH. Because the production cost is different, customers can make a reasonable choice according to their own test needs. Relative humidity is directly related to temperature. For the same absolute moisture content, the higher the temperature, the lower the relative humidity.
Fourth, the choice of control method
There are two cases of temperature and humidity test chamber: constant test chamber and alternating test chamber.
The ordinary high and low temperature test chamber generally refers to the constant high and low temperature test chamber, and its control method is: setting a target temperature, and the test chamber has the ability to automatically thermostat to the target temperature point. The control and control method of the constant temperature and humidity test box is also similar. Set a target temperature and humidity point. The test box has the ability to automatically thermostat to the target temperature and humidity point. The high and low temperature alternating test chamber has one or more high and low temperature change and cycle programs. The test chamber has the ability to complete the test process according to the preset curve, and can be accurately controlled within the range of the maximum heating and cooling rate capability The heating and cooling rate can be controlled according to the slope of the set curve. Similarly, the high and low temperature alternating heat and humidity test chamber also has preset temperature and humidity curves, and the ability to control according to presets. Of course, the alternating test chamber also has the function of a constant test chamber.
Five, the choice of manufacturers
At present, according to our market survey, there are more than 3,000 companies selling high and low temperature damp heat test chambers in the Chinese market, but there are less than 100 production manufacturers. Many of them are hand-workshop production. There are less than twenty manufacturers forming scale, and good environmental test chambers are not only reflected in price, but more importantly in product quality and service. Quality is the root and service is the basis. As one of the well-known manufacturers in the field of environmental testing equipment, Beijing Yashilin Testing Equipment Co., Ltd. has long been focusing on the research and development, production and sales of environmental testing equipment, and has repeatedly achieved good results in the industry. We warmly welcome customers to write to us to consult the environmental test chamber. We will use first-class technology, first-class products and first-class service to return our customers' care
Changxing Mingwang Rubber & Plastic Technologies Co.,Ltd. , https://www.cxmingwang.com