Climatic Chamber Manufacturer – High and Low Test Chamber

The high and low temperature test chamber is a common test equipment for simulating the heat dissipation performance, stability performance, power consumption parameters and estimating the service life of the product in the high and low temperature environment.

The selection of environmental and reliability test equipment should follow the following five basic principles
1. Reproducibility of environmental conditions
Complete and accurate reproduction of the environmental conditions that exist in nature in the laboratory is elusive. However, within a certain tolerance range, people can accurately and approximately simulate the external environmental conditions experienced by engineering products during use, storage, and transportation. The created environmental conditions (including the platform environment) surrounding the tested product should meet the requirements of the environmental conditions and their tolerances specified in the product test specification.” For example, the temperature chamber used for the test of military products should not only meet the high temperature and low temperature test values and test time specified in the national military standards GJB150.3-86 and GJB150.4-86 according to different types of products, but also meet the test values. Requirements for the uniformity of the temperature field and the accuracy of temperature control in the specification. Only in this way can the reproducibility of the environmental conditions in the environmental test be guaranteed.

2. Repeatability of environmental conditions
An environmental test equipment may be used for multiple tests of the same type of product, and a tested engineering product may also be tested in different environmental test equipment. The comparability of the test results obtained under the conditions necessarily requires the environmental conditions provided by the environmental test equipment to be repeatable. That is to say, the stress level (such as thermal stress, vibration stress, electrical stress, etc.) applied by the environmental test equipment to the tested product is consistent with the requirements of the same test specification.

The repeatability of the environmental conditions provided by the environmental test equipment is guaranteed by the national metrological verification department after passing the verification according to the verification regulations formulated by the national technical supervision agency. For this reason, the environmental test equipment must be required to meet the requirements of various technical indicators and accuracy indicators in the verification regulations, and the use time does not exceed the time limit specified in the verification cycle. If a very common electric vibrating table is used, in addition to meeting the technical indicators such as excitation force, frequency range, and load capacity, it must also meet the requirements of accuracy indicators such as lateral vibration ratio, table acceleration uniformity, and harmonic distortion specified in the verification regulations. , and the use cycle after each verification is two years, and it must be re-certified after two years before it can be put into use.

3. The controllability of environmental condition parameters
The environmental conditions provided by any environmental test equipment must be observable and controllable, not only to limit the environmental parameters within a certain tolerance range to ensure the reproducibility and repeatability of the test conditions, but also It is also necessary to proceed from the safety of product testing, in order to prevent damage to the tested product due to uncontrolled environmental conditions, resulting in unnecessary losses.

4. Exclusivity of Environmental Test Conditions
Each environmental or reliability test carried out has strict regulations on the types, magnitudes and tolerances of environmental factors, and excludes environmental factors not required for the test to penetrate into it, so as to judge and analyze the product during or after the test. In the case of failure and failure mode, the exact basis is provided. Therefore, the environmental test equipment is required to provide the specified environmental conditions, and it is not allowed to add other environmental stress interference to the tested product. For example, the table surface leakage, acceleration signal-to-noise ratio, and the total root mean square value ratio of the acceleration in and out of the band as defined in the verification regulations of the electric vibrating table. Accuracy indicators such as random signal inspection and harmonic distortion are all verification items formulated to ensure the uniqueness of environmental test conditions.

5. Safety and reliability of test equipment
Environmental tests, especially reliability tests, have a long test period, and the test objects are sometimes high-value military products. During the test, the test personnel often need to operate or test around the site, so the environmental test equipment must have the ability to operate. Safety, convenient operation, reliable use, long working life, etc., to ensure the normal operation of the test itself. Various protection, alarm measures and safety interlocking devices of the test equipment should be perfect and reliable to ensure the safety and reliability of the test personnel, the tested product and the test equipment itself. First of all, choose a suitable test equipment, and choose the inner tank of the test chamber according to the size of the test sample. When putting trial products (components, assemblies, components or complete machines) into a climate chamber for testing, In order to ensure that the tested product can meet the environmental conditions specified in the test specification, three points should be followed between the working space size of the climate chamber and the outer dimension of the tested product:
1. The volume of the tested product shall not exceed the effective working space of the test chamber (20-35 mm), and it is recommended to select no more than 30 mm 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 working cavity of the test box on the cross-section is not greater than (35-50);
3. The distance between the outer surface of the product to be tested and the wall of the test chamber should be at least 100-150mm.

Some precautions for the use of high and low temperature test chambers:
1. The dry bulb over-temperature protection switch in the test box should be checked whether it is set at the temperature of the test machine +10~20℃. If it is not handled according to the regulations, it needs to be adjusted appropriately;
2. After the testing machine is placed on the testing site, check whether the power cord is installed and grounded.
3. The testing machine needs to be filled with water before use, check whether the water volume is sufficient and whether the water cover is properly covered. Water: Pure water (conductivity in the range of 0.1 to 20 μs/cm).
4. Please check whether the over-temperature protection switch is set at 150°C. When the test is only for temperature test, the gauze should be removed. If the gauze is operated at a high temperature above 85°C, the gauze should be replaced before the next operation. Can no longer absorb water, please wash your hands before changing the gauze.
5. Check whether the wet bulb gauze of the testing machine is installed correctly and whether the humidity sensor is wet.
6. External wiring is also important. Whether the power cord is in good condition and the wiring is firm. On these issues, the power supply voltage needs to be checked carefully before starting the device;
7. Check the internal cleanliness, just like the seriousness of the appeal, check whether the box is clean, especially after the inside of the water tank needs to be rinsed with clean water, you need to add an appropriate amount of water to test the water source.
8. Before starting to use the high and low temperature test chamber or stopping repeated use for a long time, it is necessary to operate the above items, otherwise it may lead to safety accidents or irreversible failures of the equipment during use. Through this test device, try to carry out reliability test, product screening test, etc., improve the reliability of the product, and carry out quality control.
9. The high and low temperature test chamber meets the requirements of national standards such as GB 2423.1–2001, GB 2423.2–2001, and other relevant standards. It is designed and manufactured in strict accordance with the technical conditions of GB 10592–89 high and low temperature test chamber, and various high and low temperature environmental tests can be made according to military standard test requirements GJB150.3-86, GJB150.4-86, and non-standard.

Eight safety items of high and low temperature test chamber
1. The casing of the test chamber must be grounded during installation. If the test chamber is not grounded, there will be a risk of electric shock if electricity leaks.
2. Do not run the equipment before the equipment is installed, make sure the installation is reliable and then test
3. If the heating sample is placed in the chamber, please use the external power supply for the sample control power supply, and do not use the local power supply directly.
4. The operation of the chamber will generate dangerous current, non-professionals should not open the cover of the electric control cabinet
5. If the high and low temperature test chamber is not equipped with humidification function, pay attention to the difference in use and requirements when reading the instructions
6. When the machine is running, various motors and fans are controlled by the controller and start according to the instructions. Never touch the components that are temporarily in a static state with your hands to prevent the components from suddenly starting and causing personal injury. It is indeed necessary to approach the rotating parts. When working at the place, please cut off the main power switch and make sure the protective device is in good condition
7. It is forbidden to move the test chamber when there is a sample in it, otherwise the sample may reverse or fall
8. Make sure that the high and low temperature test chamber is fixed before use, that is, the casters are off the ground and the feet are on the ground, otherwise the test box will move unexpectedly when subjected to external force.

Lisun Instruments Limited was found by LISUN GROUP in 2003. LISUN quality system has been strictly certified by ISO9001:2015. As a CIE Membership, LISUN products are designed based on CIE, IEC and other international or national standards. All products passed CE certificate and authenticated by the third party lab.

Our main products are Goniophotometer, Integrating Sphere, Spectroradiometer, Surge Generator, ESD Simulator Guns, EMI Receiver, EMC Test Equipment, Electrical Safety Tester, Environmental Chamber, Temperature Chamber, Climate Chamber, Thermal Chamber, Salt Spray Test, Dust Test Chamber, Waterproof Test, RoHS Test (EDXRF), Glow Wire Test and Needle Flame Test.

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