How to Select Temperature and Humidity Climate Test Chamber

The temperature and humidity environment test chamber also called high and low temperature humidity test chamber, temperature and humidity cycle test chamber, etc.

It is an environmental simulation system and equipment commonly used in laboratories and factories. The temperature and humidity environment test chamber is used to test the performance stability of materials or products in various environments by simulating natural environments such as high temperature, low temperature, humidity, and dryness.

So how to choose a suitable temperature and humidity environment test chamber?

Here I will explain in detail how to choose a temperature and humidity environment test chamber from several aspects such as volume, temperature, humidity, and control method.

Capacity Selection:

Put the product to be tested (components, assemblies, components or complete machines) into the climate environment test chamber for testing to ensure that the environmental test conditions specified in the test specification are met around the tested product. The following points should be followed between the size of the climate chamber and the size of the tested product.

1 The volume of the test product shall not exceed (20~35)% of the effective working space of the laboratory (recommended 20%).

2 The proportion of the windward area of ​​the test product to the total area of ​​the laboratory studio shall not exceed (35~50)% (recommended 35%).

3 The distance between the outer contour of the test product and the inner wall of the test chamber is at least 100~150mm, (150mm is recommended).

The main reason for this regulation is that when the test piece is placed in a crowded channel in the box, the narrowing of the channel will lead to increased airflow, which will affect the uniformity of the environmental parameters in the test chamber. The larger the space occupied by the test piece, the more serious this effect.

According to the principle of heat conduction, the airflow temperature around the inner wall of the test space is generally 2℃~3℃ different from the center of the flow field, and high or low temperatures can even reach 5℃. The greater the difference between the experimental temperature and the external atmospheric environment, the greater the above temperature difference.

Therefore, the space within the distance (100~150mm) from the inner wall of the cavity is unusable space. Test data show that the temperature difference between the windward and leeward sides of the flow field can reach 3℃~8℃, and in severe cases can reach more than 10℃. Therefore, it is necessary to meet the two requirements of 1.1 and 1.2 as much as possible to ensure the consistency of the environmental parameters around the tested product.

For example, the relevant standards for temperature-related environmental tests include that the air flow around the test chamber shall not exceed 1.7m/s to avoid the test product and the surrounding environment from feeling unreal. If the volume or windward cross-sectional area of the test product is not limited, the actual test airflow speed will increase to exceed the maximum speed of the test standard, and the validity of the test results will be questioned.