High and low temperature environment test chamber> is a common testing equipment that cycles through high temperature, low temperature, and humidity changes, simulate extreme weather environments more realistically, and obtain accurate test results.
High and low temperature chamber environmental test chambers are widely used in various tests and include many types of products. They are necessary hardware experimental equipment for simulating product environmental adaptability tests under various ambient temperatures. It is used to test the quality of mobile phones, plastic products, metals, food, chemicals, building materials, medical care, aerospace and other products. It can be said that our lives are closely related to it. For example, the mobile phone we use in our daily life, as a fast-response electronic product, requires very sensitive electronic components in order to make a quick response. At this time, the high and low temperature test chamber requires strict screening of electronic components. Although strict screening will lose part of the cost at the beginning, because electronic components have very strict requirements on temperature and humidity, once the temperature and humidity change and do not meet the requirements, the service life of electronic components will gradually decrease.
The principle of the high and low temperature environmental test chamber:>
The heating process of the high and low temperature environmental test chamber> is after the wires in the heating system are energized Heat is generated, and then the heat generated by the air circulation system is transported to the working room through circulating air to achieve the purpose of heating. Because of its fast heating speed and high heat, it has been widely used. Some users usually have high requirements on heating rate and high temperature range. Based on this principle, wires can be added and the control system adjusted accordingly to meet this requirement.
Followed by cooling, the core equipment of this process is the compressor, the compressor compresses the low-temperature and low-pressure gas into high-temperature and high-pressure gas, which is converted into liquid by the condenser, and the evaporator evaporates these liquids, enters the low-temperature and low-pressure gas, and enters the compressor , so it circulates continuously, absorbs a large amount of heat, and finally completes cooling. The heat generated by the operation of the compressor is taken away by the fan. Energy control devices are often added to equipment to control cooling energy and energy consumption to achieve maximum temperature with minimum energy consumption and reduce costs.
In addition to refrigeration and heating, the equipment should also go through a humidity control system, humidification or dehumidification to meet the necessary humidity during the work process.
The high and low temperature environmental test chamber can mainly carry out the following test methods: >
1. High temperature test
The purpose of the test: to assess the test samples under high temperature conditions Suitability for storage or use. It is used in instruments and equipment that work in high-temperature environments such as tropical weather or steel mills.
Test equipment: high and low temperature (humid heat) test chamber.
Test conditions: Generally, a constant temperature stress and holding time are selectedbetween.
Preferred commonly used temperatures: 200°C, 175°C, 155°C, 125°C, 100°C, 85°C, 70°C, 55°C, etc.;
Preferred and commonly used test times are: 2h, 16h, 72h, 96h etc.
2. Low temperature test
Purpose of test: used to assess the adaptability of test samples for storage or use under low temperature conditions. It is often used for type testing and component screening testing in the development stage of products.
Test equipment: high and low temperature (humid heat) test chamber
Test conditions: Generally, a constant temperature and test time are selected.
The preferred and commonly used temperatures are: - 65°C, -55°C, -40°C, -25°C, -10°C, -5°C, +5°C, etc.;
The preferred and commonly used test times are: 2h, 16h, 72h, 96h, etc.
3. Constant temperature and humidity test
Purpose of the test: To assess the adaptability of the product for use and storage under hot and humid conditions, and to observe the test sample under constant temperature, no condensation, and high humidity environment for a specified period of time. The influence of the test sample is evaluated in an accelerated manner on the resistance to moisture and heat degradation.
Test equipment: constant temperature and humidity chamber.
Test conditions: test temperature; test humidity; test time.
The preferred and commonly used temperatures/humidities are: 40°C, 85%; 40°C, 93%; 85°C, 85%, etc.;
The preferred and commonly used test times are: 48h, 96h, etc.
4. Temperature and humidity cycle test
Purpose of the test: It is suitable for determining the suitability of the test sample for use and storage under the conditions of temperature cycle change and condensation on the surface.
Test equipment: high and low temperature (humid heat) test chamber.
Test conditions: selected temperature, humidity, number of cycles, temperature change rate, and duration.
High and low temperature test standard:>
GB_T 2423.2-2008 Environmental testing for electrical and electronic products Part 2: Test method Test B: High temperature
GBT 2423.1-2008 Environmental testing for electrical and electronic products Part 2: Test method Test A: Low temperature
IEC 60068-2-2 Basic environmental test procedures Part 2-2: Test Test B: Dry heat
IEC 60068-2- 1: 2007 Environmental Test for Electrical and Electronic Products: Low Temperature
The impact of high temperature and low temperature on electronic (plastic) products:>
1. High temperature may overheat the product and affect the use Safety and reliability, even damage. Such as:
1. Make the grouting glue for insulation or sealing melt and lose, and the grease melt and lose, thus causing damage to the tower.
2. Change the material properties.The elasticity or mechanical strength of the sexual components is reduced, shortening the service life of the product
4. Accelerating the degradation and aging process of polymer materials and insulation materials, shortening the service life of the product.
2. The impact of low temperature on mechanical, electrical, and electronic products is multi-faceted and varies depending on the characteristics of the product's energy, degree and structure, such as:
1. Freeze the electrolyte. As a result, electrolytic capacitors and batteries cannot be used normally
2. The viscosity of lubricating oil increases and even condenses and freezes, affecting the starting performance of the product
3. It affects the normal starting of electronic products and increases instrument errors
4. Use Materials become brittle. For example, plastics and steel are prone to brittle damage at low temperatures. The hardness of rubber materials increases and their elasticity decreases.
Basic requirements that products should meet after high and low temperature tests:>
Product quality after high and low temperature tests is generally based on product technical conditions or technical agreements. requirements inspection. For example, the impact of high temperature environment on the performance of motor products is manifested in the increase in resistance of conductive materials, resulting in changes in current. For motors with precision requirements, it will also affect the accuracy. Therefore, after the high temperature test, the insulation resistance should be measured in the test box, and its value should not be less than 5MΩ. At the same time, other properties of the motor should also be tested. Generally speaking, if a product can meet the following basic requirements after a temperature test, it is considered to meet the high and low temperature requirements.
1. There is no damage, deformation or other defects on the surface of the product. If the surface is coated, there should be no peeling, bubbling or discoloration of the coating.
2 For plastic parts, there are no cracks, blistering, deformation, etc. on the surface.
3. Rubber products are free from aging, adhesion, softening and cracking.
4 There is no flow in the welded parts of the product parts.
5 Product performance data and structural functions must meet the technical requirements, and there should not be any other defects that hinder the normal operation of the product.
The high and low temperature humidity and heat alternating test chamber meets IEC60068-2-1 (IOS2423.1), IEC60068-2-2 (IOS2423.2), IEC60068-2-78, IEC60598-1 , IOS2423.17, IOS5170.2, IOS5170.5 and other standards. It can be applied to CFL/LED lighting industry testing and meets the IES LM-80-08 standard. It can also be used in electrical products, electronic components, materials and other industries.