High and low temperature environmental test chamber> is a common test equipment, through high temperature, low temperature, humidity cycle Changes, more realistic simulation of extreme weather conditions, to obtain accurate test results.
In various tests, the high and low temperature chamber environmental test chamber is widely used, and it contains many types of products. It is the necessary hardware experimental equipment for simulating the environmental adaptability test of products 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 needs to strictly screen the 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 delivered to the working chamber through the 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 the cycle is continuous, absorbing a lot of heat, and finally cooling is completed. The heat generated by the compressor is carried 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 cooling and heating, the equipment should also pass through the humidity control system, humidification or dehumidification to meet the necessary humidity in the working 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. Applied to instruments, equipment, etc. that work in high temperature environments such as tropical weather or steel factories.
Test equipment: high and low temperature (humid heat) test chamber.
Test conditions: generally select a constant temperature stress and hold timebetween.
Preferred commonly used temperatures: 200°C, 175°C, 155°C, 125°C, 100°C, 85°C, 70°C, 55°C, etc.;
Preferred commonly used test times are: 2h, 16h, 72h, 96h etc.
2. Low temperature test
Purpose of the test: To assess the adaptability of the test samples for storage or use under low temperature conditions. It is often used in the type test of products in the development stage, the screening test of components, etc.
Test equipment: high and low temperature (humid heat) test chamber
Test conditions: generally select a constant temperature and test time.
The preferred commonly used temperatures are: - 65°C, -55°C, -40°C, -25°C, -10°C, -5°C, +5°C, etc.;
The preferred 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 humid and hot conditions, and to observe the test samples in a constant temperature, no condensation, high humidity environment for a specified time To evaluate the effect of the test sample on the resistance to heat and humidity degradation in an accelerated manner.
Test equipment: constant temperature and humidity chamber.
Test conditions: test temperature; test humidity; test time.
The preferred commonly used temperature/humidity are: 40°C, 85%; 40°C, 93%; 85°C, 85%; 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, cycle times, temperature change rate, 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.4. Accelerate the deterioration and aging process of polymer materials and insulating materials, shortening the service life of products.
Second, the impact of low temperature on mechanical, electrical, and electronic products is multifaceted, and varies according to the characteristics of the product's energy, degree of auxiliary structure, such as:
1. Freezing the electrolyte t Cause electrolytic capacitors and batteries cannot be used normally
2. The viscosity of lubricating oil increases, or even condenses and freezes, affecting the starting performance of the product
3. Affecting the normal startup of electronic products and increasing the error of the instrument
4. The material becomes brittle, such as plastic and steel, which are prone to brittle crack damage at low temperature, and the hardness of the rubber material increases, and the elasticity decreases.
The basic requirements that the product should meet after the high and low temperature test:>
The quality of the product after the high and low temperature test is generally stipulated in the product technical conditions or technical agreement requirements inspection. For example, the impact of high temperature environment on the performance of motor products is manifested in the increase in the resistance of conductive materials, resulting in changes in current, and 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 lower than 5MΩ, and other performances of the motor should be tested at the same time. In general, after the temperature test, if the product can meet the following basic requirements, it is considered that the product meets the high and low temperature requirements.
1 The surface of the product has no defects such as damage and deformation. If the surface is coated, there should be no peeling, blistering or discoloration of the coating.
2 For plastic parts, there are no cracks, blisters and deformations on the surface.
3 Rubber products have no aging, bonding, softening and cracking.
4 There is no flow phenomenon in the welding part of the product parts.
5 The performance data and structure of the product meet the requirements of the technical conditions, and there should be no 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.