The constant chamber is a controllable air humidity and temperature environmental testing equipment. It can simulate products in use in different environments. Such as high temperature and low humidity, low temperature and high humidity environment. To test its adaptability, durability, and other performance parameters. In scientific research and experimental work, a constant chamber is indispensable experimental equipment. A constant temperature humidity chamber can provide a constant humidity temperature environment. At the same time, it can provide stable conditions for the experiment.
The chamber is an integral part of the product manufacturing and development process. To buy the best equipment for the experiments required. Buy constant temperature and humidity chambers need to pay attention to many factors. However, the market has different specifications and functions of a constant humidity chamber. How to choose a constant test chamber suitable for their needs has become an issue.
According to the test needs to choose the test chamber model
First, according to the test parameters select the test chamber model.
For example, if you need to determine the performance of high humidity conditions. Then you need to choose the model of the test chamber with high humidity control capability. To ensure the reliability and validity of test results. Users buy equipment based on test standards and specifications.
Secondly, users need to consider the application scenario of the test chamber.
Different industries and test projects need different test chambers. For example, climatic environment tests, biological culture tests, material tests, and so on. Different tests need different temperatures, humidity, and other conditions. Thus, we need to choose the right test chamber according to the specific needs.
Besides, users choose the type of test chamber that suits their needs. Different types of test chambers are applied in different testing scenarios. For example, constant temperature humidity chambers are suitable for testing in most industries. It is suitable for testing in aerospace, electronics, automotive, and chemical materials. When choosing a chamber, you must consider the testing needs and performance parameters.
Usage requirements include test time, size, and weight of the test chamber.
These factors will affect the efficiency and cost of the test. Thus, they need to consider when selecting a test chamber.
Finally, it is necessary to understand the standards and test requirements.
There are some industries where test chambers must meet specific specifications. For example, the food safety industry test chamber must follow food hygiene standards. Test chambers for medical devices must follow the standards for medical devices, etc.
The performance of constant temperature humidity chamber
Performance includes temperature range, humidity range, temperature fluctuation, humidity fluctuation, and so on. All these factors will affect the credibility of the test results. So users need to consider these factors together.
Selection of temperature and humidity range
First, we should consider the temperature and humidity range of the constant chamber. Each experiment has specific temperature and humidity requirements. If the experiment requires a higher precision of temperature and humidity control. Then you need to choose a device with a wider range. If the experiment on the temperature and humidity requirements are low. Then you can choose relatively simple equipment. To avoid parameter inconsistencies leading to experimental failure or inaccurate results. when selecting a constant chamber, one must ensure meets the experiment requirements.
Selection of temperature range
At present, the temperature test chamber range is roughly -73 ~ + 177 ℃, or -70 ~ +180 ℃. There are also some manufacturers of -70 ~ +150 ℃, -40 ~ +150 ℃, -20 ~ +150 ℃, there are also high temperature to 150 ℃. These temperature ranges can meet the majority of military and civilian product needs. Unless there is a special need. Such as the installation location near the engine and other heat sources of the product. Do not blindly raise the upper limit of temperature. Because the higher the upper limit temperature. The greater the temperature difference between the outside and inside of the chamber. This will lead to the uniformity of the flow field inside the box is also worse. The smaller the volume of the studio that is allowed to be utilized. The higher the need for the sealing of the box body is also, which increases the production cost of the box body.
Selection of humidity range
The humidity range of constant temperature and humidity chambers is generally 30 ~ 98% RH or 20 ~ 98% RH. High humidity can be achieved by spraying water vapor or atomized water droplets. Low humidity and cold temperatures are harder to control. Because the absolute humidity content of the test is very low. Sometimes much lower than the absolute water content of the atmosphere. Now the need to dehumidify the air flowing in the box, so that the air becomes dry.
Determine the temperature control ability of the test chamber
We need to focus on the temperature control range and other indicators. If the product is in a specific temperature environment to perform better. You need to buy a higher temperature control ability for the test chamber. At the same time, we also need to ensure that the control precision is high enough. Because high control precision ensures the accuracy of the experimental results.
Selection of suitable humidity control capability
Humidity control is important for the testing of some chemicals, and other industries. Select the humidity control accuracy according to the test environment, and other factors. For example, some items in the low temperature and humidity produce static electricity. So you need to choose the test chamber with an anti-static function.
Cooling method selection
The test chamber has two forms air-cooled, and water-cooled. Constant temperature humidity chambers usually use air cooling. Large constant temperature and humidity chambers use water cooling. General thermal shock test chamber using water-cooled more.
Power supply selection
Constant temperature humidity test chambers are generally more than a three-phase power interface. Temperature is below -40℃, box more than 225L, should choose a four-phase power interface. This is more stable for the laboratory power to extend the life of the equipment itself.
Functions and control methods
Constant temperature and humidity experimental chamber usually has a variety of functions. Such as alarm function, data logging function, and so on. According to the specific needs, choose the equipment with the corresponding functions. Besides, pay attention to the control mode of the equipment. Some devices provide touch screen or computer control. It can be more convenient to operate and watch the experimental box.
Stable operation and precise control are the important characteristics of the test chamber. We want the equipment to maintain set humidity and temperature levels. To ensure the accuracy and reproducibility of the experimental results. On the one hand, we can consult the manufacturer or check the product manual. On the other hand, understand the operational stability and temperature humidity control accuracy.
Reliability and safety of constant temperature and humidity test chambers
First, we need to ensure that the test chamber can work properly. Meanwhile, users should emphasize the safety performance of a constant temperature and humidity chamber. Such as avoiding the operator causing harm to equipment. And the test process prevents accidents.
Climate chamber working chamber environment
The higher the upper limit temperature, the greater the temperature difference. And the volume of the studio available to the user is also smaller. Box sealing requirements are also higher so that the production cost increases.
Volume size selection
To meet environmental test condition specifications. Users will be tested in the climatic environment box for testing. The working size and the test product outline dimensions should follow the following provisions:
- (a) The volume of the test product will not exceed (20-35)% of the effective working space of the test chamber. It is recommended that choose 20%. For the product in the test heat recommended selection of not more than 10%.
- (b) The ratio of the windward area of the product under test to the total area of the chamber studio is not more than (35-50)%. It recommended that the user choose 35%.
- (c) The test product profile surface from the test box wall distance of at least 100 ~ 150mm. It recommended a selection of 150mm.
The three provisions mentioned above are harmonized and interdependent. To 1 m³ box, for example, the area ratio of 1: (0.35 ~ 0.5) is equal to the volume ratio of 1: (0.207 ~ 0.354). Distance from the box wall 100 ~ 150 mm equal to the volume of the ratio of 1: (0.343 ~ 0.512).
Including the above three provisions. The volume of the outer contour of the product to be measured should be 1/3 to 1/5 of the volume of the chamber. This provision is made for the following reasons:
- The operator placed the specimen inside the box, resulting in a congested aisle. Narrowing of the channel increases the airflow rate. This failed to coincide with the reproduction of environmental conditions. Because of the environment test in the test specimen airflow velocity should not exceed 1.7m / s. In the unloaded test chamber average wind speed of 0.6 ~ 0.8m / s, not more than 1m / s. The flow field of the wind speed may be increased by (50 ~ 100) percent. The average largest wind speed is (1 ~ 1.7) m / s, to meet the requirements of the standard. If in the test without limitation increase the volume of the test piece or the wind area. The maximum wind speed specified in the test standard will be lower than the airflow wind speed. This will affect the validity of the test results.
- The accuracy index of the environmental parameters is the result of testing under no load. Putting in a specimen affects the homogeneity of the environmental parameters. The more space the sample takes up, the greater this effect will be. This results in a temperature difference of 3 to 8 °C between the leeward and windward sides of the flow field. Severe cases can reach more than 10 ℃. Want to ensure the consistency of the environmental parameters of the sample. Both requirements (a) and (b) must be met as far as possible.
- The temperature difference between the airflow near the wall of the box and the center of the flow field is 2 to 3℃. In the upper and lower limits of high and low temperatures, may also reach 5 ℃. The box wall and the temperature difference between the nearby flow field is generally 2 ~ 3 ℃. So the distance from the box wall (100 ~ 150mm) within the space is not available space.
Compare different constant temperature and humidity box manufacturers use accessories
Controller, compressor, and box material are very important accessories.
The brain of the constant temperature humidity chamber is the controller. It is a very important part, it is good or bad to determine the results of the test. Buy a constant temperature humidity chamber before you can understand the mainstream controller. South Korean TEMI880 controller price is more expensive. One to eight thousand or so, but the quality is very good. And then look at the controller used by manufacturers. From this, you can know the good and bad constant temperature and humidity chamber.
The housing is generally made of stainless steel, but stainless steel varies. Such as “201 stainless steel” will rust after a long time, and the price on the market is relatively cheap. ChiuVention’s constant temperature and humidity test box using SUS304 stainless steel plate. 304 stainless steel has a brightness close to the mirror surface, the touch of hard ice Dan Pi cold. It belongs to the more avant-garde decorative materials. It has excellent corrosion resistance, compatibility, strong toughness, and other series of characteristics.
The compressor affects the constant temperature humidity chamber cooling effect. When purchasing, users should note the brand of compressor used. Environmental chamber offer is low, so we must pay attention to whether the second best. the use of miscellaneous brands of compressors. Even the use of second-hand compressors or refurbished compressors. Such product quality can not be guaranteed, buy with caution!
Manufacturer and service
You can find out about the manufacturer’s technical prowess, etc. before you buy. Choosing a reliable manufacturer can guarantee the quality of the test chamber. It can also provide better technical support and solutions.
Compare after-sales service
Buy a constant temperature humidity chamber not only consider the price. More should consider the after-sales service and cost. You can visit the manufacturer before purchasing the product. There is also to see the buying of the products of other customers on the product evaluation.
Attention to the maintenance of the test chamber
Under the long-term incorrect operation of the chamber, there will be some problems. Such as inaccurate temperature control, unstable humidity changes, and noise increase. Thus, users need to know more about the basic problems of the test chamber. Such as replacement parts, maintenance, and cleaning and maintenance issues. This can ensure the normal use of the test chamber and extend the service life of the test chamber. Thus, in the buy of a constant test chamber, we need to pay attention to the maintenance. At the same time, we also need to understand the daily maintenance, maintenance cycle, and so on. Ensure that the test chamber has high stability and reliability in normal use.
In summary, selecting a constant temperature humidity chamber requires consideration of many factors. Including size and capacity, operational stability, control accuracy, functions, and other factors. Buy a constant temperature humidity chamber, you can learn information from various aspects. According to the specific circumstances for comprehensive consideration, and comparison and evaluation. To choose the suitable equipment to improve the experiment’s efficiency and accuracy.