Solar Module EVA Film Introduction 2
EVA-UV test:
Description: Test the attenuation ability of EVA to withstand ultraviolet (UV) irradiation, after a long time of UV irradiation, EVA film will appear brown, penetration rate decreased... And so on.
EVA environmental test project and test conditions:
Humid heat: 85℃ / RH 85%; 1,000 hrs
Thermal cycle: -40℃ ~ 85℃; 50 cycles
Wet freezing test: -40℃ ~ 85℃ / RH 85%; 10 times UV: 280~385nm/ 1000w/200hrs (no cracking and no discoloration)
EVA Test Conditions (NREL) :
High temperature test: 95℃ ~ 105℃/1000h
Humidity and heat: 85℃/85%R.H./>1000h[1500h]
Temperature cycle: -40℃←→85℃/>200Cycles
(No bubbles, no cracking, no desticking, no discoloration, no thermal expansion and contraction)
UV aging: 0.72W/m2, 1000 hrs, 60℃(no cracking, no discoloration) Outdoor: > California sunshine for 6 months
Example of EVA characteristics change under Damp heat test:
Discoloration, atomization, Browning, delamination
Comparison of EVA bond strength at high temperature and humidity:
Description: EVA film at 65℃/85%R.H and 85℃/85%R.H. The degradation of the bond strength was compared at 65℃/85%R.H under two different wet and hot conditions. After 5000 hours of testing, the degradation benefit is not high, but EVA at 85℃/85%R.H. In the test environment, the adhesion is quickly lost, and there is a significant reduction in bond strength in 250 hours.
EVA-HAST unsaturated pressurized vapor test:
Objective: Since EVA film needs to be tested for more than 1000 hours at 85℃/85%R.H., which is equal to at least 42 days, in order to shorten the test time and accelerate the test speed, it is necessary to increase the environmental stress (temperature & humidity & pressure) and speed up the test process in the environment of unsaturated humidity (85%R.H.).
Test conditions: 110℃/85%R.H./264h
EVA-PCT pressure digester test:
Objective: The PCT test of EVA is to increase the environmental stress (temperature & humidity) and expose EVA to wetting vapor pressure exceeding one atmosphere, which is used to evaluate the sealing effect of EVA and the moisture absorption status of EVA.
Test condition: 121℃/100%R.H.
Test time: 80h(COVEME) / 200h(toyal Solar)
EVA and CELL bond tensile force test:
EVA: 3 ~ 6Mpa Non-EVA material: 15Mpa
Additional information from EVA:
1. The water absorption of EVA will directly affect its sealing performance of the battery
2.WVTR < 1×10-6g/m2/day(NREL recommended PV WVTR)
3. The adhesive degree of EVA directly affects its impermeability. It is recommended that the adhesive degree of EVA and cell should be greater than 60%
4. When the bonding degree reaches more than 60%, thermal expansion and contraction will no longer occur
5. The bonding degree of EVA directly affects the performance and service life of the component
6. Unmodified EVA has low cohesion strength and is prone to thermal expansion and contraction leading to chip fragmentation
7.EVA peeling strength: longitudinal ≧20N/cm, horizontal ≧20N/cm
8. The initial light transmittance of the packaging film is not less than 90%, and the internal decline rate of 30 years is not less than 5%
Reliability - Environment
Reliability analysis is based on quantitative data as the basis of product quality, through the experimental simulation, the product in a given time, specific use of environmental conditions, the implementation of specific specifications, the probability of successful completion of work objectives, to quantitative data as the basis for product quality assurance. Among them, environmental testing is a common analysis item in reliability analysis.
Environmental reliability testing is a test performed to ensure that the functional reliability of a product is maintained during the specified life period, under all circumstances in which it is intended to be used, transported or stored. The specific test method is to expose the product to natural or artificial environmental conditions, to evaluate the performance of the product under the environmental conditions of actual use, transportation and storage, and to analyze the impact of environmental factors and their mechanism of action.
Sembcorp's Nanoreliability Analysis laboratory mainly evaluates IC reliability by increasing temperature, humidity, bias, analog IO and other conditions, and selecting conditions to accelerate aging according to IC design requirements. The main test methods are as follows:
TC temperature cycle test
Experimental standard: JESD22-A104
Objective: To accelerate the effect of temperature change on the sample
Test procedure: The sample is placed in a test chamber, which cycles between specified temperatures and is held at each temperature for at least ten minutes. The temperature extremes depend on the conditions selected in the test method. The total stress corresponds to the number of cycles completed at the specified temperature.
capacity of equipment
Temperature Range
-70℃—+180℃
Temperature Change Rate
15℃/min linear
Internal Volume
160L
Internal Dimension
W800*H500 * D400mm
External Dimension
W1000 * H1808 * D1915mm
Quantity of sample
25 / 3lot
Time/pass
700 cycles / 0 Fail2300 cycles / 0 Fail
BLT high temperature bias test
Experimental standard: JESD22-A108
Objective: The influence of high temperature bias on samples
Test process: Put the sample into the experimental chamber, set the specified voltage and current limit value in power supply, try run at room temperature, observe whether the limited current occurs in power supply, measure whether the input chip terminal voltage meets the expectation, record the current value at room temperature, and set the specified temperature in chamber. When the temperature is stable at the set value, power on at high temperature and record the high temperature current value
Equipment capacity:
Temperature Range
+20℃—+300℃
Internal Volume
448L
Internal Dimension
W800*H800 * D700mm
External Dimension
W1450 * H1215 * D980mm
Quantity of sample
25 / 3lot
Time/pass
Case Temperature 125℃ ,1000hrs/ 0 Fail
HAST highly accelerated stress test
Experimental standard: JESD22-A110/A118 (EHS-431ML, EHS-222MD)
Objective: HAST provides constant multiple stress conditions, including temperature, humidity, pressure, and bias. Carried out to assess the reliability of non-enclosed packaged equipment operating in humid environments. Multiple stress conditions can accelerate the infiltration of moisture through the encapsulation mold compound or along the interface between the external protective material and the metal conductor passing through the encapsulation. When water reaches the surface of the bare piece, the applied potential sets up an electrolytic condition that corrodes the aluminum conductor and affects the DC parameters of the device. Contaminants present on the chip surface, such as chlorine, can greatly accelerate the corrosion process. In addition, too much phosphorus in the passivation layer can also react under these conditions.
Device 1 and device 2
Equipment capacity:
Quantity of sample
25 / 3lot
Time/pass
130℃，85%RH ,96hrs/ 0 Fail
110℃，85%RH ,264hrs/ 0 Fail
Device 1
Temperature Range
-105℃—+142.9℃
Humidity Range
75%RH—100%RH
Pressure Range
0.02—0.196MPa
Internal Volume
51L
Internal Dimension
W355*H355 * D426mm
External Dimension
W860 * H1796 * D1000mm
Device 2
Temperature Range
-105℃—+142.9℃
Humidity Range
75%RH—100%RH
Pressure Range
0.02—0.392MPa
Internal Volume
180L
Internal Dimension
W569*H560 * D760mm
External Dimension
W800 * H1575 * D1460mm
THB temperature and humidity cycle test
Experimental standard: JESD22-A101
Objective: The influence of temperature and humidity change on the sample
Experimental process: Put the sample into the experimental chamber, set the specified voltage and current limit value in power supply, try run at room temperature, observe whether the limited current occurs in power supply, measure whether the input chip terminal voltage meets the expectation, record the current value at room temperature, and set the specified temperature in chamber. When the temperature is stable at the set value, power on at high temperature and record the high temperature current value
Equipment capacity:
Temperature Range
-40℃—+180℃
Humidity Range
10%RH—98%RH
Temperature Conversion Rate
3℃/min
Internal Volume
784L
Internal Dimension
W1000*H980 * D800mm
External Dimension
W1200 * H1840 * D1625mm
Quantity of sample
25 / 3lot
Time/pass
85℃，85%RH ,1000hrs/ 0 Fail
Procedure temperature and humidity cycle, there has no humidity when temperature over 100℃
TSA&TSB temperature shock test
Experimental standard: JESD22-A106
Objective: To accelerate the effect of temperature change on the sample
Test process: The sample is put into the test chamber, and the specified temperature is set inside the chamber. Before heating up, it is confirmed that the sample has been fixed on the mold, which has prevented damage due to the sample falling into the chamber during the experiment.
Equipment capacity:
TSA
TSB
Temperature Range
-70℃—+200℃
-65℃—+200℃
Temperature Change Rate
≤5min
＜20S
Internal Volume
70L
4.5L
Internal Dimension
W410*H460 * D3700mm
W150*H150 * D200mm
External Dimension
W1310 * H1900 * D1770mm
W1200 * H1785 * D1320mm
Application of TCT Temperature Cycle Chamber in Optical Communication Industry
The arrival of 5G makes people feel the rapid development of mobile Internet, and optical communication technology as an important basis has also been developed. At present, China has built the world's longest optical fiber network, and with the continuous advancement of 5G technology, optical communication technology will be more widely used. The development of optical communication technology not only allows people to enjoy faster network speed, but also brings more opportunities and challenges. For example, new applications such as cloud gaming, VR, and AR require more stable and high-speed networks, and optical communication technology can meet these needs. At the same time, optical communication technology has also brought more innovation opportunities, such as intelligent medical care, intelligent manufacturing and other fields, will use optical communication technology to achieve more efficient and accurate operation. But you know what? This amazing technology cannot be achieved without the credit of macro environmental test equipment, especially the TC temperature cycle test chamber, which is a rapid temperature change test chamber. This article introduces you to the optical communication product reliability test quality manager - rapid temperature change laboratory.
First, let's talk briefly about optical communication. Some people also say that it is called optical communication, so they are two in the end is not a concept. In fact, they are two of the same concept. Optical communication is the use of optical signals for communication technology, and optical communication is based on optical communication, through optical devices such as optical fibers, optical cables to achieve data transmission. Optical communication technology is widely used, such as our daily use of fiber optic broadband, mobile phone optical sensors, optical measurement in aerospace and so on. It can be said that optical communication has become an important part of modern communication field. So why is optical communication so popular? In fact, it has many advantages, such as high-speed transmission, large bandwidth, low loss and so on.
Common optical communication products include: optical cable, fiber switch, fiber modem, etc., used to transmit and receive optical signals of optical fiber communication equipment; Temperature sensor, strain sensor, displacement sensor, etc., can measure various physical quantities in real time and other optical fiber sensors; Erbium-doped optical amplifier, erbium-doped ytterbium-doped optical amplifier, Raman amplifier, etc., used to expand the intensity of optical signals and other optical amplifiers; Helium-neon laser, diode laser, fiber laser, etc., are light sources in optical communication, used to produce high brightness, directional and coherent laser light and other lasers; Photodetectors, optical limiter, photodiodes, etc., for receiving optical signals and converting them into electrical signals and other optical receivers; Optical switches, optical modulators, programmable optical arrays, etc. are used to control and adjust optical signal transmission and routing and other optical controllers. Let's take mobile phones as an example and talk about the application of optical communication products on mobile phones:
1. Optical fiber: Optical fiber is generally used as a part of the communication line, due to its fast transmission speed, communication signals are not easily affected by external interference and other characteristics, has become an important part of mobile phone communication.
2. Photoelectric converter/optical module: photoelectric converter and optical module are devices that convert optical signals into electrical signals, and are also a very important part of mobile phone communication. In the era of high-speed communication such as 4G and 5G, the speed and performance of such equipment need to be continuously improved to meet the needs of fast and stable communication.
3. Camera module: In the mobile phone, the camera module generally includes CCD, CMOS, optical lens and other parts, and its quality and performance also have a significant impact on the quality of optical communication of the mobile phone.
4. Display: Mobile phone displays generally use OLED, AMOLED and other technologies, the principle of these technologies are related to optics, but also an important part of mobile phone optical communication.
5. Light sensor: Light sensor is mainly used in mobile phones for environmental light sensing, proximity sensing and gesture sensing, and is also an important mobile phone optical communication product.
It can be said that optical communication products fill all aspects of our life and work. However, the production and use environment of optical communication products is often changeable, such as high or low temperature weather environment when working outdoors, or the use of a long time will also encounter changes in thermal expansion and contraction. So how is the reliable use of these products achieved? That has to mention our protagonist today - rapid temperature change test chamber, also known as TC box in the optical communication industry. In order to ensure that optical communication products still work normally under various environmental conditions, it is necessary to carry out rapid temperature change tests on optical communication products. The rapid temperature change test chamber can simulate a variety of different temperature and humidity environments, and simulate instantaneous extreme environmental changes in the real world within a rapid range. So how is the rapid temperature change test chamber applied in the optical communication industry?
1. Optical module performance test: Optical module is a key component of optical communication, such as optical transceiver, optical amplifier, optical switch, etc. The rapid temperature change test chamber can simulate different temperature environments and test the performance of the optical module at different temperatures to evaluate its adaptability and reliability.
2. Reliability test of optical devices: optical devices include optical fibers, optical sensors, grating, photonic crystals, photodiodes, etc. The rapid temperature change test chamber can test the temperature change of these optical devices and evaluate their reliability and life based on the test results.
3. Optical communication system simulation test: The rapid temperature change test chamber can simulate various environmental conditions in the optical communication system, such as temperature, humidity, vibration, etc., to test the performance, reliability and stability of the entire system.
4. Technology research and development: The optical communication industry is a technology-intensive industry, which needs to constantly develop new technologies and new products. The rapid temperature change test chamber can be used to test the performance and reliability of new products, helping to accelerate the development and market of new products.
In summary, it can be seen that in the optical communication industry, the rapid temperature change test chamber is usually used to test the performance and reliability of optical modules and optical devices. Then when we use the rapid temperature change test chamber for testing, different optical communication products may require different standards. The following are rapid temperature change test standards for some common optical communication products:
1. Optical fiber: Common test standards There are common optical fiber rapid temperature change test standards are the following: IEC 61300-2-22: The standard defines the stability and durability test method of optical fiber components, section 4.3 of which specifies the thermal stability test method of optical fiber components, in the case of rapid temperature changes to the optical fiber components for measurement and evaluation. GR-326-CORE: This standard specifies reliability test requirements for fiber optic connectors and adapters, including thermal stability tests to assess the reliability of fiber optic connectors and adapters in temperature changing environments. GR-468-CORE: This standard defines the performance specifications and test methods for fiber optic connectors, including temperature cycle testing, accelerated aging testing, etc., to verify the reliability and stability of fiber optic connectors under various environmental conditions. ASTM F2181: This standard defines a method for fiber failure testing under high temperature and high humidity environmental conditions to evaluate the long-term durability of the fiber. And the above standards such as GB/T 2423.22-2012 are tested and evaluated for the reliability of optical fiber in rapid temperature changes or long-term high temperature and high humidity environments, which can help the majority of manufacturers to ensure the quality and reliability of optical fiber products.
2. Photoelectric converter/optical module: The common rapid temperature change test standards are GB/T 2423.22-2012, GR-468-CORE, EIA/TIA-455-14 and IEEE 802.3. These standards mainly cover the test methods and specific implementation steps of photoelectric converters/optical modules, which can ensure the performance and reliability of products in different temperature environments. Among them, the GR-468-CORE standard is specifically for the reliability requirements of optical converters and optical modules, including temperature cycle test, wet heat test and other environmental tests, requiring optical converters and optical modules to maintain stable and reliable performance in long-term use.
3. Optical sensor: The common rapid temperature change test standards are GB/T 27726-2011, IEC 61300-2-43 and IEC 61300-2-6. These standards mainly cover the test methods and specific implementation steps of the temperature change test of the optical sensor, which can ensure the performance and reliability of the product in different temperature environments. Among them, the GB/T 27726-2011 standard is the standard for the performance test method of optical sensors in China, including the environmental test method of optical fiber sensors, which requires the optical sensor to maintain stable performance in a variety of working environments. IEC 60749-15 standard is the international standard for the temperature cycle test of electronic components, and it also has reference value for the rapid temperature change test of optical sensors.
4. Laser: Common rapid temperature change test standards are GB/T 2423.22-2012 "Electrical and electronic products environmental test Part 2: Test Nb: temperature cycle test", GB/T 2423.38-2002 "Basic test methods for electrical components Part 38: Temperature resistance test (IEC 60068-2-2), GB/T 13979-2009 "Laser product Performance test method", IEC 60825-1, IEC/TR 61282-10 and other standards mainly cover the laser temperature change test method and specific implementation steps. It can ensure the performance and reliability of products in different temperature environments. Among them, the GB/T 13979-2009 standard is the standard for the performance test method of laser products in China, including the environmental test method of the laser under temperature changes, requiring the laser to maintain stable performance in a variety of working environments. The IEC 60825-1 standard is a specification for the integrity of laser products, and there are also relevant provisions for the rapid temperature change test of lasers. In addition, the IEC/TR 61282-10 standard is one of the guidelines for the design of optical fiber communication systems, which includes methods for the environmental protection of lasers.
5. Optical controller: The common fast temperature change test standards are GR-1209-CORE and GR-1221-CORE. GR-1209-CORE is a reliability standard for optical fiber equipment, mainly for the reliability test of optical connections, and specifies the reliability experiment of optical connection systems. Among them, the rapid temperature cycle (FTC) is one of the test projects, which is to test the reliability of optical fiber modules under rapidly changing temperature conditions. During the test, the optical controller needs to perform temperature cycling in the range of -40 ° C to 85 ° C. During the temperature cycle, the module should maintain normal function and not produce abnormal output, and the test time is 100 temperature cycles. GR-1221-CORE is a reliability standard for fiber optic passive devices and is suitable for the testing of passive devices. Among them, the temperature cycle test is one of the test items, which also requires the optical controller to be tested in the range of -40 ° C to 85 ° C, and the test time is 100 cycles. Both of these standards specify the reliability test of the optical controller in the environment of temperature change, which can determine the stability and reliability of the optical controller under harsh environmental conditions.
In general, different rapid temperature change test standards may focus on different test parameters and test methods, it is recommended to choose the corresponding test standards according to the use of specific products.
Recently, when we discuss the reliability verification of optical modules, there is a contradictory indicator, the number of temperature cycles of optical module verification, there are 10 times, and 20 times, 100 times, or even 500 times.
Frequency definitions in two industry standards:
The references to these standards have clear sources and are correct.
For the 5G forward optical module, our opinion is that the number of cycles is 500, and the temperature is set at -40 °C ~85 °C
The following is the description of the 10/20/100/500 above in the original text of GR-468(2004)
Because of the limited space, this article introduces the use of rapid temperature change test chamber in the optical communication industry. If you have any questions when using rapid temperature change test chamber and other environmental test equipment, welcome to discuss with us and learn together.
IEC 60068-2 Combined Condensation and Temperature and Humidity Test
In the IEC60068-2 specification, there are a total of five kinds of humid heat tests. In addition to the common 85℃/85%R.H., 40℃/93%R.H. fixed-point high temperature and high humidity, there are two more special tests [IEC60068-2-30, IEC60068-2-38], they are alternating wet and humid cycle and temperature and humidity combined cycle, so the test process will change temperature and humidity. Even multiple groups of program links and cycles applied in IC semiconductors, parts, equipment, etc. To simulate the outdoor condensation phenomenon, evaluate the material's ability to prevent water and gas diffusion, and accelerate the product's tolerance to deterioration, the five specifications are organized into a comparison table of the differences in the wet and heat test specifications, and the main points of the test are explained in detail for the wet and heat combined cycle test, and the test conditions and points of GJB in the wet and heat test are supplemented.
IEC60068-2-30 alternating humid heat cycle test
Note: This test uses the test technique of maintaining humidity and temperature alternations to make moisture permeate into the sample and produce condensation (condensation) on the surface of the product to confirm the adaptability of the component, equipment or other products in use, transportation and storage under the combination of high humidity and temperature and humidity cycle changes. This specification is also suitable for large test samples. If the equipment and the test process need to keep the power heating components for this test, the effect will be better than IEC60068-2-38, the high temperature used in this test has two (40 °C, 55 °C), the 40 °C is to meet most of the world's high temperature environment, while 55 °C meets all the world's high temperature environment, the test conditions are also divided into [cycle 1, cycle 2], In terms of severity, [Cycle 1] is higher than [Cycle 2].
Suitable for side products: components, equipment, various types of products to be tested
Test environment: the combination of high humidity and temperature cyclic changes produces condensation, and three kinds of environments can be tested [use, storage, transportation ([packaging is optional)]
Test stress: Breathing causes water vapor to invade
Whether power is available: Yes
Not suitable for: parts that are too light and too small
Test process and post-test inspection and observation: check the electrical changes after moisture [do not take out the intermediate inspection]
Test conditions: humidity: 95% R.H. warming] after [humidity maintain (25 + 3 ℃ low temperature - - high temperature 40 ℃ or 55 ℃)
Rising and cooling rate: heating (0.14℃/min), cooling (0.08~0.16℃/min)
Cycle 1: Where absorption and respiratory effects are important features, the test sample is more complex [humidity not less than 90%R.H]
Cycle 2: In the case of less obvious absorption and respiratory effects, the test sample is simpler [humidity is not less than 80%R.H.]
IEC60068-2-30 Alternating temperature and humid test (condensation test)
Note: For component types of parts products, a combination test method is used to accelerate the confirmation of the test sample's tolerance to degradation under high temperature, high humidity and low temperature conditions. This test method is different from the product defects caused by respiration [dew, moisture absorption] of IEC60068-2-30. The severity of this test is higher than that of other humid heat cycle tests, because there are more temperature changes and [respiration] during the test, and the cycle temperature range is larger [from 55℃ to 65℃]. The temperature variation rate of the temperature cycle also becomes faster [temperature rise :0.14℃/min becomes 0.38℃/min, 0.08℃/min becomes 1.16 ℃/min]. In addition, different from the general humid heat cycle, the low temperature cycle condition of -10℃ is increased, which accelerates the breathing rate and makes the water condensing in the gap of the substitute icing. Is the characteristic of this test specification, the test process allows power and load power test, but can not affect the test conditions (temperature and humidity fluctuation, rising and cooling rate) because of the heating of the side product after power, due to the change of temperature and humidity during the test process, but the top of the test chamber can not condenses water droplets to the side product.
Suitable for side products: components, metal components sealing, lead end sealing
Test environment: combination of high temperature, high humidity and low temperature conditions
Test stress: accelerated breathing + frozen water
Whether it can be powered on: it can be powered on and external electric load (it can not affect the conditions of the test chamber because of power heating)
Not applicable: Can not replace moist heat and alternating humid heat, this test is used to produce defects different from respiration
Test process and post-test inspection and observation: check the electrical changes after moisture [check under high humidity conditions and take out after test]
Test conditions: damp temperature and humidity cycle (25 ↔ 65 + 2 ° C / 93 + 3% r.h.) - low temperature cycle (25 ↔ 65 + 2 ℃ / 93 + 3% r.h. -- 10 + 2 ° C) X5 cycle = 10 cycle
Rising and cooling rate: heating (0.38℃/min), cooling (1.16 °C/min)
GJB150-o9 humid heat test
Description: The wet and heat test of GJB150-09 is to confirm the ability of equipment to withstand the influence of hot and humid atmosphere, suitable for equipment stored and used in hot and humid environment, equipment prone to high humidity storage or use, or equipment may have potential problems related to heat and humidity. Hot and humid locations may occur throughout the year in tropical areas, seasonal occurrences in mid-latitudes, and in equipment subjected to comprehensive changes in pressure, temperature and humidity. The specification specifically emphasizes 60 ° C /95%R.H. This high temperature and humidity does not occur in nature, nor does it simulate the humid and thermal effect after solar radiation, but it can find potential problems in the equipment. However, it is not possible to reproduce complex temperature and humidity environments, assess long-term effects, and reproduce humidity effects associated with low humidity environments.
IEC 60068-2
Instructions:
IEC(International Electrotechnical Association) is the world's oldest non-governmental international electrical standardization organization, for the people's livelihood of the electronic products to develop relevant test specifications and methods, such as: mainframe board, notebook computers, tablets, smartphones, LCD screens, game consoles... The main spirit of its test is extended from IEC, the main representative of which is IEC60068-2, environmental test conditions its [environmental test] refers to the sample exposed to natural and artificial environments, but the performance of its actual use, transportation and storage conditions are evaluated. The environmental test of the sample can be uniform and linear through the use of standardized standards. Environmental testing can simulate whether the product can adapt to environmental changes (temperature, humidity, vibration, temperature change, temperature shock, salt spray, dust) at different stages (storage, transport, use). And verify that the characteristics and quality of the product itself will not be affected by it, low temperature, high temperature, temperature impact can produce mechanical stress, this stress makes the test sample more sensitive to the subsequent test, impact, vibration can produce mechanical stress, this stress can make the sample immediately damaged, air pressure, alternating humid heat, constant humid heat, corrosion application of these tests and can be continued thermal and mechanical stress test effects.
Important IEC specification sharing:
IEC69968-2-1- Cold
Test purpose: To test the ability of automotive components, equipment or other component products to operate and store at low temperatures.
Test methods are divided into:
1.Aa: Temperature sudden change method for non-thermal specimens
2.Ab: Temperature gradient method for non-thermal specimens
3.Ad: Temperature gradient method of thermogenic specimen
Note:
Aa:
1. Static test (without power supply).
2. First cool down to the specified temperature of the specification before placing the test part.
3. After stability, the temperature difference of each point on the specimen does not exceed ±3℃.
4. After the test is completed, the specimen is placed under standard atmospheric pressure until the fog is completely removed: no voltage is added to the specimen during the transfer process.
5. Measure after returning to the original condition (at least 1hr).
Ab:
1. Static test (without power supply).
2. The specimen is placed in the cabinet at room temperature, and the temperature change of the cabinet temperature does not exceed 1℃ per minute.
3. The specimen shall be kept in the cabinet after the test, and the temperature change of the cabinet temperature shall not exceed 1℃ per minute to return to the standard atmospheric pressure; The specimen should not be charged during temperature change.
4. Measure after returning to the original condition (at least 1hr). (The difference between the temperature and the air temperature is more than 5℃).
Ac:
1. Dynamic test (plus power supply) when the temperature of the specimen is stable after charging, the temperature of the specimen surface is the most hot spot.
2. The specimen is placed in the cabinet at room temperature, and the temperature change of the cabinet temperature does not exceed 1℃ per minute.
3. The specimen should be kept in the cabinet after the test, and the temperature change of the cabinet temperature should not exceed 1℃ per minute, and return to the standard atmospheric pressure; The specimen should not be charged during temperature change.
4. Measure after returning to the original condition (at least 1hr).
Test conditions:
1. Temperature :-65,-55,-40,-25,-10,-5,+5°C
2. Resident time :2/16/72/96 hours.
3. Temperature variation rate: no more than 1℃ per minute.
4. Tolerance error :+3°C.
Test setup:
1. Heat generating specimens should be placed in the center of the test cabinet and the wall of the cabinet > 15cm
Sample to specimen > 15cm test cabinet to test volume ratio > 5:1.
2. For heat-generating specimens, if air convection is used, the flow rate should be kept to a minimum.
3. The specimen should be unpacked, and the fixture should have the characteristics of high heat conduction.
IEC 60068-2-2- Dry heat
Test purpose: To test the ability of components, equipment or other component products to operate and store in high temperature environments.
The test method is:
1. Ba: Temperature sudden change method for non-thermal specimens
2.Bb: Temperature gradient method for non-thermal specimens
3.Bc: Temperature sudden change method for thermogenic specimens
4.Bd: Temperature gradient method for thermogenic specimens
Note:
Ba:
1. Static test (without power supply).
2. First cool down to the specified temperature of the specification before placing the test part.
3. After stability, the temperature difference of each point on the specimen does not exceed +5℃.
4. After the test is completed, place the specimen under standard atmospheric pressure and return to the original condition (at least 1hr).
Bb:
1. Static test (without power supply).
2. The specimen is placed in the cabinet at room temperature, and the temperature change of the cabinet temperature does not exceed 1℃ per minute, and the temperature is reduced to the temperature value specified in the specification.
3. The specimen shall be kept in the cabinet after the test, and the temperature change of the cabinet temperature shall not exceed 1℃ per minute to return to the standard atmospheric pressure; The specimen should not be charged during temperature change.
4. Measure after returning to the original condition (at least 1hr).
Bc:
1. Dynamic test (external power supply) When the temperature of the specimen is stable after charging, the difference between the temperature of the hottest spot on the surface of the specimen and the air temperature is more than 5℃.
2. Heat up to the specified temperature of the specification before placing the test part.
3. After stability, the temperature difference of each point on the specimen does not exceed +5℃.
4. After the test is completed, the specimen will be placed under the standard atmospheric pressure, and the measurement will be carried out after the original condition is returned (at least 1hr).
5. The average temperature of the decimal point on the plane of 0~50mm on the bottom surface of the specimen.
Bd:
1. Dynamic test (external power supply) when the temperature of the specimen is stable after charging, the temperature of the most hot spot on the surface of the specimen is more than 5°C different from the air temperature.
2. The specimen is placed in the cabinet at room temperature, and the temperature change of the cabinet temperature does not exceed 1℃ per minute, and rises to the specified temperature value.
3. Return to standard atmospheric pressure; The specimen should not be charged during temperature change.
4. Measure after returning to the original condition (at least 1hr).
Test conditions:
1. The temperature 1000,800,630,500,400,315,250,200,175,155,125,100,85,70,55,40,30 ℃.
1. Resident time: 2/16/72/96 hours.
2. Temperature variation rate: no more than 1℃ per minute. (Average in 5 minutes)
3. Tolerance error: tolerance of ±2℃ below 200℃. (200~1000℃ tolerance ±2%)
IEC 60068-2-2- Test method Ca: Steady damp heat
1. Test purpose:
The purpose of this test method is to determine the adaptability of components, equipment or other products to operation and storage at constant temperature and high relative humidity.
Step 2: Scope
This test method can be applied to both heat-dissipating and non-heat-dissipating specimens.
3. No limits
4. Test steps:
4.1 Specimens shall be inspected visually, electrically and mechanically in accordance with relevant specifications before testing.
4.2 The test specimen must be placed in the test cabinet in accordance with the relevant specifications. In order to avoid the formation of water droplets on the test specimen after it is placed in the cabinet, it is best to preheat the temperature of the test specimen to the temperature condition in the test cabinet in advance.
4.3 The specimen shall be insulated in accordance with the specified residence.
4.4 If specified in the relevant specifications, functional tests and measurements shall be performed during or after the test, and the functional tests shall be performed in accordance with the cycle required in the specifications, and the test pieces shall not be moved out of the test cabinet.
4.5 After the test, the specimen must be placed under standard atmospheric conditions for at least one hour and at most two hours to return to its original condition. Depending on the characteristics of the specimen or the different laboratory energy, the specimen can be removed or retained in the test cabinet to wait for recovery, if you want to remove the time to be as short as possible, preferably not more than five minutes, if maintained in the cabinet the humidity must be reduced to 73% to 77% R.H. within 30 minutes, while the temperature must also reach the laboratory temperature within 30 minutes +1℃ range.
5. Test conditions
5.1 Test temperature: The temperature in the test cabinet should be controlled within the range of 40+2°C.
5.2 Relative humidity: The humidity in the test cabinet should be controlled at 93(+2/-3)% R.H. Within the range.
5.3 Resident time: The resident time can be 4 days, 10 days, 21 days or 56 days.
5.4 Test tolerance: temperature tolerance is +2℃, error of packet content measurement, slow change of temperature and temperature difference in the temperature cabinet. However, in order to facilitate the maintenance of humidity within a certain range, the temperature of any two points in the test cabinet should be maintained within the minimum range as far as possible at any time. If the temperature difference exceeds 1 ° C, the humidity changes beyond the permissible range. Therefore, even short-term temperature changes may need to be controlled within 1 ° C.
6. Test setup
6.1 Temperature and humidity sensing devices must be installed in the test cabinet to monitor the temperature and humidity in the cabinet.
6.2 There shall be no condensation water droplets on the test specimen at the top or wall of the test cabinet.
6.3 The condensed water in the test cabinet must be discharged continuously and shall not be used again unless it is purified (re-purifed).
6.4 When the humidity in the test cabinet is achieved by spraying water into the test cabinet, the moisture resistance coefficient shall not be less than 500Ω.
7. Other
7.1 The temperature and humidity conditions in the test cabinet must be uniform and similar to those in the vicinity of the temperature and humidity sensor.
7.2 The temperature and humidity conditions in the test cabinet shall not be changed during the power-on or functional test of the specimen.
7.3 Precautions to be taken when removing moisture from the specimen surface shall be detailed in the relevant specifications.
IEC 68-2-14 Test method N: Temperature variation
1. Test purpose
The purpose of this test method is to determine the effect of the specimen on the environment of temperature change or continuous temperature change.
Step 2: Scope
This test method can be divided into:
Test method Na: Rapid temperature change within a specified time
Test method Nb: Temperature change at specified temperature variability
Test method Nc: Rapid temperature change by double liquid immersion method.
The first two items apply to components, equipment or other products, and the third item applies to glass-metal seals and similar products.
Step 3 Limit
This test method does not validate high or low temperature environmental effects, and if such conditions are to be validated, "IEC68-2-1 test Method A:" cold "or "IEC 60068-2-2 Test Method B: dry heat" should be used.
4. Test procedure
4.1 Test method Na:
Rapid temperature change in a specific time
4.1.1 Specimens shall be inspected visually, electrically and mechanically in accordance with relevant specifications before testing.
4.1.2 The specimen type shall be unpacked, unpowered and ready for use or other conditions specified in relevant specifications. The initial condition of the specimen was room temperature in the laboratory.
4.1.3 Adjust the temperature of the two temperature cabinets respectively to the specified high and low temperature conditions.
4.1.4 Place the specimen in the low-temperature cabinet and keep it warm according to the specified residence time.
4.1.5 Move the specimen into the high-temperature cabinet and keep it warm according to the specified residence time.
4.1.6 The transfer time of high and low temperature shall be subject to the test conditions.
4.1.7 Repeat the procedure of Steps 4.1.4 and 4.1.5 four times
4.1.8 After the test, the specimen should be placed under standard atmospheric conditions and kept for a certain time to make the specimen reach temperature stability. The response time shall refer to the relevant regulations.
4.1.9 After the test, the specimens shall be inspected visually, electrically and mechanically in accordance with relevant specifications.
4.2 Test method Nb:
Temperature change at a specific temperature variability
4.2.1 The specimens shall be inspected visually, electrically and mechanically in accordance with relevant specifications before testing.
4.2.2 Place the test piece in the temperature cabinet. The shape of the test piece should be unpacked, unpowered and ready for use or other conditions specified in relevant specifications. The initial condition of the specimen was room temperature in the laboratory.
The specimen can be made operational if required by the relevant specification.
4.2.3 The temperature of the cabinet shall be lowered to the prescribed low temperature condition, and the insulation shall be carried out according to the prescribed residence time
4.2.4 The temperature of the cabinet shall be raised to the specified high temperature condition, and heat preservation shall be carried out according to the specified residence time
4.2.5 The temperature variability of high and low temperature shall be subject to the test conditions.
4.2.6 Repeat the procedure in Steps 4.2.3 and 4.2.4:
Electrical and mechanical tests shall be performed during the test.
Record the time used for electrical and mechanical testing.
After the test, the specimen should be placed under standard atmospheric conditions and kept for a certain time to make the specimen reach the temperature stability recovery time referred to the relevant specifications.
After the test, the specimens shall be inspected visually, electrically and mechanically in accordance with the relevant specifications
5. Test conditions
Test conditions can be selected by the following appropriate temperature conditions and test time or in accordance with the relevant specifications,
5.1 Test method Na:
Rapid temperature change in a specific time
High temperature: 1000800630500400315250200175155125100,85,70,55,4030 ° C
Low temperature :-65,-55,-40,-25.-10.-5 °C
Humidity: Vapor content per cubic meter of air should be less than 20 grams (equivalent to 50% relative humidity at 35 ° C).
Residence time: The temperature adjustment time of the temperature cabinet can be 3 hours, 2 hours, 1 hour, 30 minutes or 10 minutes, if there is no provision, it is set to 3 hours. After the test piece is placed in the temperature cabinet, the temperature adjustment time cannot exceed one-tenth of the residence time. Transfer time: manual 2~3 minutes, automatic less than 30 seconds, small specimen less than 10 seconds.
Number of cycles :5 cycles.
Test tolerance: The tolerance of temperature below 200℃ is +2℃
The tolerance of the temperature between 250 and 1000C is +2% of the test temperature. If the size of the temperature cabinet cannot meet the above tolerance requirements, the tolerance can be relaxed: the tolerance of the temperature below 100 ° C is ±3 ° C, and the tolerance of the temperature between 100 and 200 ° C is ±5 ° C (the tolerance relaxation should be indicated in the report).
5.2 Test method Nb:
Temperature change at a specific temperature variability
High temperature: 1000800630500400315250200175155125100,85,70 55403 0 'C
Low temperature :-65,-55,-40,-25,-10,-5,5℃
Humidity: Vapor per cubic meter of air should be less than 20 grams (equivalent to 50% relative humidity at 35 ° C) Residence time: including rising and cooling time can be 3 hours, 2 hours, 1 hour, 30 minutes or 10 minutes, if there is no provision, set to 3 hours.
Temperature variability: The average temperature fluctuation of the temperature cabinet within 5 minutes is 1+0.2 ° C /min, 3+0.6 ° C /min, or 5+1 ° C /min.
Number of cycles :2 cycles.
Test tolerance: The tolerance of temperature below 200℃ is +2℃.
The tolerance of the temperature between 250 and 1000℃C is +2% of the test temperature. If the size of the temperature cabinet cannot meet the above tolerance requirements, the tolerance can be relaxed. The tolerance of the temperature below 100 ° C is +3 ° C. The temperature between 100 ° C and 200 ° C is +5 ° C. (The tolerance relaxation should be indicated in the report).
6. Test setup
6.1 Test method Na:
Rapid temperature change in a specific time
The difference between the inner wall temperature of the high and low temperature cabinets and the temperature test specifications shall not exceed 3% and 8%(shown in °K) respectively to avoid thermal radiation problems.
The thermogenic specimen should be placed in the center of the test cabinet as far as possible, and the distance between the specimen and the cabinet wall, the specimen and the specimen should be greater than 10 cm, and the ratio of the volume of the temperature cabinet and the specimen should be greater than 5:1.
6.2 Test method Nb:
Temperature change at a specific temperature variability
Specimens shall be inspected visually, electrically and mechanically in accordance with relevant specifications before testing.
The specimen shall be in unpacked, unpowered and ready for use condition or other conditions specified in relevant specifications. The initial condition of the specimen was room temperature in the laboratory.
Adjust the temperature of the two temperature cabinets respectively to the specified high and low temperature conditions
The specimen is placed in a low-temperature cabinet and kept warm according to the specified residence time
The specimen is placed in a high temperature cabinet and insulated according to the specified residence time.
The transfer time of high and low temperature shall be performed according to the test conditions.
Repeat the procedure of steps d and e four times.
After the test, the specimen should be placed under standard atmospheric conditions and kept for a certain time to make the specimen reach the temperature stability recovery time referred to the relevant specifications.
After the test, the specimens shall be inspected visually, electrically and mechanically in accordance with the relevant specifications
6.3 Test method NC:
Rapid temperature change of double liquid soaking method
The liquid used in the test shall be compatible with the specimen and shall not harm the specimen.
7. Others
7.1 Test method Na:
Rapid temperature change in a specific time
When the specimen is placed in the temperature cabinet, the temperature and air flow rate in the cabinet must reach the specified temperature specification and tolerance within one-tenth of the holding time.
The air in the cabinet must be maintained in a circle, and the air flow rate near the specimen must not be less than 2 meters per second (2m/s).
If the specimen is transferred from the high or low temperature cabinet, the holding time cannot be completed for some reason, it will stay in the previous holding state (preferably at low temperature).
7.2 Test method Nb:
The air in the cabinet must be maintained in a circle at a specific temperature variability, and the air flow rate near the specimen must not be less than 2 meters per second (2m/s).
7.3 Test method NC:
Rapid temperature change of double liquid soaking method
When the specimen is immersed in the liquid, it can be quickly transferred between the two containers, and the liquid cannot be stirred.
What are the High and Low Temperature Explosion-proof Devices?
Due to the particularity of the test product, during the test process, the test product may produce a large amount of gas in the high temperature or high pressure state, which may catch fire and explode. In order to ensure production safety, preventive safety protection devices can be used as optional equipment. Therefore, the high and low temperature test chamber needs to add special devices - explosion-proof devices when testing these special products. Today, let's talk about what are the high and low temperature explosion-proof devices.
1. Pressure relief port
When the air generated in the test chamber increases and the gas pressure in the chamber reaches a threshold, the pressure relief port automatically opens and releases the pressure outwards. This design ensures that when the system overpressure, the pressure can be released, thereby preventing the system from collapsing or exploding. The location and number of pressure relief ports are determined according to the specific fire extinguishing system design and application requirements.
2. Smoke detector
The smoke detector mainly realizes fire prevention by monitoring the concentration of smoke. The ionic smoke sensor is used inside the smoke detector. The ionic smoke sensor is a kind of sensor with advanced technology and stable and reliable operation. When the concentration of smoke particles in the chamber is greater than the threshold, it will sense and alarm to remind the production to stop operation and achieve the effect of preventing fire.
3. Gas detector
A gas detector is an instrument that detects the concentration of a gas. The instrument is suitable for dangerous places where combustible or toxic gases exist, and can continuously detect the content of the measured gas in the air within the lower explosive limit for a long time. The gas diffuses into the working electrode of the sensor through the back of the porous film, where the gas is oxidized or reduced. This electrochemical reaction causes a change in the current flowing through the external circuit, and the gas concentration can be measured by measuring the size of the current.
4. Smoke exhaust system
The air inlet of the pressurized fan is directly connected with the outdoor air. In order to prevent the outdoor air from being polluted by smoke, the air inlet of the supply fan should not be located at the same level as the air outlet of the exhaust machine. A one-way air valve should be installed on the outlet or inlet air pipe of the fan. Mechanical smoke exhaust system adopts smoke exhaust fan for mechanical exhaust air. According to relevant information, a well-designed mechanical smoke exhaust system can discharge 80% of the heat in the fire, so that the temperature of the fire scene is greatly reduced, and it has an important role in the safety of personnel evacuation and fire fighting.
5. Electromagnetic lock and mechanical door buckle
The electromagnetic lock uses the electromagnetic principle to achieve the fixing of the lock body, without the need to use a mechanical lock tongue, so the electromagnetic lock does not exist the possibility of mechanical lock tongue damage or forced destruction. The electromagnetic lock has a high anti-impact strength, when the external impact force acts on the lock body, the lock body will not be easily destroyed, and there will be certain protective measures when the explosion occurs.
6. Automatic fire extinguishing device
The automatic fire extinguishing device is mainly composed of four parts: detector (thermal energy detector, flame detector, smoke detector), fire extinguisher (carbon dioxide extinguisher), digital temperature control alarm and communication module. Through the digital communication module in the device, the real-time temperature changes, alarm status and fire extinguisher information in the fire area can be remotely monitored and controlled, which can not only remotely monitor the various states of the automatic fire extinguishing device, but also master the real-time changes in the fire area, which can minimize the loss of life and property when the fire occurs.
7. Indicator and warning light
Communicate equipment status or transmission status by visual and acoustic signals to machine operators, technicians, production managers and plant personnel.
What are the Safety Protection Systems of the High and Low Temperature Test Chamber?
1, Leakage/surge protection:Leakage circuit breaker leakage protection FUSE.RC electronic surge protection from Taiwan
2, The controller internal self-automatic detection and protection device
(1) Temperature/humidity sensor: The controller controls the temperature and humidity in the test area within the set range through the temperature and humidity sensor
(2) Controller overtemperature alarm: when the heating tube in the chamber continues to heat up and exceeds the temperature set by the internal parameters of the controller, the buzzer in it will alarm and need to be manually reset and reused
3, Fault detection control interface: external fault automatic detection protection Settings
(1) The first layer of high temperature overtemperature protection: operation control overtemperature protection Settings
(2) The second layer of high temperature and overtemperature protection: the use of anti-dry burning overtemperature protector to protect the system will not be heated all the time to burn the equipment
(3) Water break and air burning protection: humidity is protected by anti-dry burning overtemperature protector
(4) Compressor protection: refrigerant pressure protection and over-load protection device
4, Fault abnormal protection: when the fault occurs, cut off the control power supply and the fault cause indication and alarm output signal
5, Automatic water shortage warning: the machine water shortage active warning
6, Dynamic high and low temperature protection: with the setting conditions to dynamically adjust the high and low temperature protection value
Comparison of Natural Convection Test Chamber, Constant Temperature and Humidity Test Chamber and High Temperature Oven
Instructions:
Home entertainment audio-visual equipment and automotive electronics are one of the key products of many manufacturers, and the product in the development process must simulate the adaptability of the product to temperature and electronic characteristics at different temperatures. However, when using a general oven or thermal and humidity chamber to simulate the temperature environment, either the oven or thermal and humidity chamber has a test area equipped with a circulating fan, so there will be wind speed problems in the test area.
During the test, the temperature uniformity is balanced by rotating the circulating fan. Although the temperature uniformity of the test area can be achieved through the wind circulation, the heat of the product to be tested will also be taken away by the circulating air, which will be significantly inconsistent with the actual product in the wind-free use environment (such as the living room, indoor).
Because of the relationship of wind circulation, the temperature difference of the product to be tested will be nearly 10℃. In order to simulate the actual use of environmental conditions, many people will misunderstand that only the test chamber can produce temperature (such as: oven, constant temperature humidity chamber) can carry out natural convection test. In fact, this is not the case. In the specification, there are special requirements for wind speed, and a test environment without wind speed is required. Through the natural convection test equipment and software, the temperature environment without passing through the fan (natural convection) is generated, and the test integration test is performed for the temperature detection of the product under test. This solution can be used for home related electronics or real-world ambient temperature testing in confined Spaces (e.g., large LCD TV, car cockpits, automotive electronics, laptops, desktops, game consoles, stereos, etc.).
Unforced air circulation test specification :IEC-68-2-2, GB2423.2, GB2423.2-89 3.31 The difference between the test environment with or without wind circulation and the test of products to be tested:
Instructions:
If the product to be tested is not energized, the product to be tested will not heat itself, its heat source only absorbs the air heat in the test furnace, and if the product to be tested is energized and heated, the wind circulation in the test furnace will take away the heat of the product to be tested. Every 1 meter increase in wind speed, its heat will be reduced by about 10%. Suppose to simulate the temperature characteristics of electronic products in an indoor environment without air conditioning. If an oven or a constant temperature humidifier is used to simulate 35 °C, although the environment can be controlled within 35 °C through electric heating and compressor, the wind circulation of the oven and the thermal and humidify test chamber will take away the heat of the product to be tested. So that the actual temperature of the product to be tested is lower than the temperature under the real windless state. It is necessary to use a natural convection test chamber without wind speed to effectively simulate the actual windless environment (indoor, no starting car cockpit, instrument chassis, outdoor waterproof chamber... Such environment).
Comparison table of wind speed and IC product to be tested:
Description: When the ambient wind speed is faster, the IC surface temperature will also take away the IC surface heat due to the wind cycle, resulting in the faster the wind speed and the lower the temperature.
Comparison of Climatic Test and Environmental Test
Climate environment test -- constant temperature and humidity test chamber, high and low temperature test chamber, cold and hot shock test chamber, wet and heat alternating test chamber, rapid temperature change test chamber, linear temperature change test chamber, walk-in constant temperature and humidity test chamber, etc. They all involve temperature control.
Because there are multiple temperature control points to choose from, the climate chamber temperature control method also has three solutions: inlet temperature control, product temperature control and "cascade" temperature control. The first two are single-point temperature control, and the third is two-parameter temperature control.
Single point temperature control method has been very mature and widely used.
Most of the early control methods were "ping-pong" switch control, commonly known as heating when it's cold and cooling when it's hot. This control mode is a feedback control mode. When the temperature of the circulating air flow is higher than the set temperature, the electromagnetic valve of refrigeration is opened to deliver cold volume to the circulating air flow and reduce the temperature of the air flow. Otherwise, the circuit switch of the heating device is switched on to directly heat the circulating air flow. Raise the temperature of the air stream. This control mode requires that the refrigeration device and heating components of the test chamber are always in a standby working state, which not only wastes a lot of energy, but also the controlled parameter (temperature) is always in an "oscillation" state, and the control accuracy is not high.
Now the single-point temperature control method is mostly changed to the universal proportional differential integral (PID) control method, which can give the controlled temperature correction according to the past change of the controlled parameter (integral control) and the change trend (differential control), which not only saves energy, but also the "oscillation" amplitude is small and the control accuracy is high.
Dual-parameter temperature control is to collect the temperature value of the air inlet of the test chamber and the temperature value near the product at the same time. The air inlet of the test chamber is very close to the installation position of the evaporator and heater in the air modulation room, and its magnitude directly reflects the air modulation result. Using this temperature value as the feedback control parameter has the advantage of quickly modulating the status parameters of the circulating air.
The temperature value near the product indicates the real temperature environmental conditions suffered by the product, which is the requirement of the environmental test specification. Using this temperature value as the parameter of feedback control can ensure the effectiveness and credibility of the temperature environmental test, so this approach takes into account the advantages of both and the requirements of the actual test. The dual-parameter temperature control strategy can be the independent "time-sharing control" of the two groups of temperature data, or the weighted two temperature values can be combined into one temperature value as a feedback control signal according to a certain weighting coefficient, and the value of the weighting coefficient is related to the size of the test chamber, the wind speed of the circulating air flow, the size of the temperature change rate, the heat output of the product work and other parameters.
Because heat transfer is a complex dynamic physical process, and is greatly affected by the atmospheric environment conditions around the test chamber, the working state of the tested sample itself, and the complexity of the structure, it is difficult to establish a perfect mathematical model for the temperature and humidity control of the test chamber. In order to improve the stability and accuracy of control, fuzzy logic control theory and method are introduced in the control of some temperature test chambers. In the control process, the thinking mode of human is simulated, and the predictive control is adopted to control the temperature and humidity space field more quickly.
Compared with the temperature, the selection of humidity measurement and control points is relatively simple. During the circulation flow of the well-regulated humid air into the high and low temperature cycle test chamber, the exchange of water molecules between the wet air and the test piece and the four walls of the test chamber is very small. As long as the temperature of the circulating air is stable, the circulating air flow from entering the test chamber to exiting the test chamber is in the process. The moisture content of wet air changes very little. Therefore, the relative humidity value of the detected air at any point of the circulating air flow field in the test box, such as the inlet, the middle stream of the flow field or the return air outlet, is basically the same. Because of this, in many test chambers that use the wet and dry bulb method to measure humidity, the wet and dry bulb sensor is installed at the return air outlet of the test chamber. Moreover, from the structural design of the test box and the convenience of maintenance in use, the wet and dry bulb sensor used for relative humidity measurement and control is placed at the return air inlet for easy installation, and also helps to regularly replace the wet bulb gauze and clean the temperature sensing head of the resistance PT100, and according to the requirements of the GJB150.9A wet heat test 6.1.3. The wind speed passing through the wet-bulb sensor should not be lower than 4.6m/s. The wet-bulb sensor with a small fan is installed at the return air outlet for easier maintenance and use.
Application of Thermal Shock Test Chamber
Thermal shock test chamber is an indispensable test equipment for aviation, automotive, home appliances, scientific research and other fields, used to test and determine the parameters and performance of electrical, electronic and other products and materials after temperature environment changes in high temperature, low temperature, alternating humidity and heat degree or constant test; Or constant humid heat test after the temperature environment changes the parameters and performance. Applicable to schools, factories, research positions, etc.
1, the high and low temperature impact test chamber with automatic, high-precision system loop, any part action, fully PLC locking processing, all use PID automatic calculation control, high temperature control precision, advanced scientific air circulation cycle design, make the indoor temperature uniform, avoid any dead corners; The complete protection device avoids any possible hidden dangers and ensures the long-term reliability of the equipment.
2, high and low temperature impact test chamber adopts advanced measuring device, and the controller adopts a large color LCD man-machine touch dialogue LCD man-machine interface controller, which is simple to operate, easy to learn, stable and reliable, and displays the complete system operation status, execution and setting program curve in Chinese and English. With 96 test specifications independently set, impact time 999 hours 59 minutes, cycle cycle 1~999 times can be set, can realize the automatic operation of the refrigerator, to a large extent to achieve automation, reduce the workload of the operator, can automatically start and stop working at any time.
3, The left side of the chamber has a test hole with a diameter of 50mm, which can be used for wiring test parts with external power load. Can be independently set high temperature, low temperature and cold and thermal shock three different conditions of the function, and in the implementation of cold and thermal shock conditions, you can choose two or three trough and cold flushing, hot flushing impact function, with high and low temperature testing machine function.
Solar Module Test Project
1. solar module reliability test specification:
The reliability test of the solar module is to confirm the performance of the solar module (early), and the test specifications for the module are mainly IEC61215, IEC61646, UL1703 three test specifications. IEC61215 is suitable for crystalline (Si) modules; IEC61646 is suitable for thin-film (Thin-flm) modules; The UL1703 is suitable for both crystalline and thin film solar modules. In addition, the GB and CNS solar energy specifications are partially modified from the IEC.
2. the relationship and importance of Macro Exhibition and solar energy test projects:
According to IEC61215, IEC61646 test items a total of about 10 (solar module test items corresponding to the general table). Among them, the test equipment manufactured by Hongjian will be used, and the relevant test conditions are temperature cycling (Thermal cycling, 10.11). There are three categories of Humidity freeze (10.12) and Damp heat (10.13), while UL1703 only has two items of temperature cycle wet freezing without the item of damp heat.
3. Thermal cycling test (Thermal cycling)lEC61215-10-11:
Solar module temperature cycle test is used to determine the fatigue, thermal failure, or other stress failure caused by repeated changes in temperature of the module. The current number of temperature cycles is 200 times, and the future trend will be 600 times (according to the test results of the American Association for Renewable Energy [NREL], the power degradation rate of 600 times is greater than 200 times as much as twice).
Through the temperature cycle: defects of the module can be found: crack growth, module cracks, warping, sealing material delamination, point shedding, glass corrosion... Let's wait.
Temperature conditions: Low temperature :-40℃, high temperature :85°C(IEC), 90 °C(UL), the fastest temperature variability (average):100 °C /h, 120 °C /h, relevant measurements need to be carried out during the test (using the Qingsheng solar energy measurement system), the test process needs to measure the module: module surface temperature, voltage and current, ground continuity, insulation... Let's wait.
4. the purpose of the temperature cycle test process through bias:
Temperature cycle test process, the specification requires through bias, the purpose of the test is to make the defective Cell heat to accelerate aging and accelerate failure test purposes, so it needs to be energized above 25℃ during the temperature cycle process, the laboratory in the United States has statistics, It was found that the difference between the failure rate of the solar module with power and without power is as high as 30%, and the experimental data indicates that if there is no power, the solar module is not easy to fail in the temperature cycle environment, so when carrying out the temperature cycle test of the solar cell (Cel)& module, it needs to be matched with a special measurement system.
5. the introduction of wet freezing test lEC61215-10-12:
Description: To determine whether the component is sufficiently resistant to corrosion damage and the ability of moisture expansion to expand the material molecules, frozen moisture is the stress to determine the cause of failure. For the product to be tested, the test stress is high temperature and high humidity (85℃/85%R.H) to low temperature (-40℃ humidity 85%R.H). Maintain to 25℃), and low temperature rise to high temperature and high humidity, rather than 85℃/85%R.H./20 hours, 85℃/85%R.H./20 hours, the purpose of 85℃/85%R.H./20 hours is to let the module surrounding full of water, 20 hours dwell time is too short, is not enough for water to penetrate into the module and junction box inside.
Through wet freezing test: Module defects can be found: cracks, warping, severe corrosion, lamination of sealing materials, failure of adhesive delamination junction box & water accumulation, wet insulation **... Etc.
Test conditions: 85 ℃ / 85% R.H. (h) 20-40 ℃ (0.5 ~ 4 h), maximum heat up 100, 120 ℃ / h, and maximum temperature of 200 ° C/h.
6. Purpose of wet freezing test:
The wet freezing test method is mainly to perform two kinds of damage to the solar module in a snowy environment.
(1). High temperature and humidity (85℃/85%R.H.) drop to -4℃ before 25℃, humidity should be controlled at 85%+5% RH. The purpose of this is to simulate the high humidity sudden change before the snow.
Before the snow, the environment will show a high humidity state, and when the temperature drops to 0℃, the water gas around the module and the junction box sealant will freeze. When the water gas freezes, its volume will expand to 1.1 times of the original, and the destruction method of ice expansion after the water gas penetrates the material gap through the water gas to achieve the purpose of this test. At present, the statistical results of wet freezing have the highest damage to junction box sealant, which will cause junction box degumming and water, and the failure ratio of module is estimated at 7%.
(2). The purpose of heating up from low temperature (-40℃) and humidity (50℃/85%R.H.) is to simulate the temperature rise in the module at sunrise in a snowy climate. Although the outdoor environment is still below 0℃, the solar module will generate electricity when there is light, and because the snow is still on the module, the heat spot effect will occur in the module. The temperature inside the module will also reach 50 ° C.
7. wet heat test (Damp heat) test IEC61215-10-13:
Description: To determine the ability of the module to resist long-term moisture penetration, according to the test results of BP Solar, its 1000 hours is not enough. The actual condition is found that the time to make the module have problems needs at least 1250 hours. According to the current requirements of the specification, the wet heat test process is not powered on, but the future trend is also to be powered on (positive and reverse bias), because it can accelerate the aging and failure of solar cells.
Test conditions: 85℃/85%R.H., time :1000 hours Defects can be found through the wet and thermal test: CELL delamination EVA(delamination, discoloration, bubble formation, atomization, Browning), connection line blackening, TCO corrosion, spot corrosion, Thin-film yellow discoloration, junction box degumming off
Working Principle of UV Weathering Test Chamber
Uv weathering test chamber is a kind of experimental equipment specially used to test the durability and stability of materials and products under ultraviolet radiation. Its working principle revolves around mimicking UV radiation conditions in the natural environment to assess how materials behave when exposed to sunlight for long periods of time. The chamber is equipped with a series of high-intensity ultraviolet light sources that effectively emit ultraviolet light in a specific wavelength range, mimicking the UV-A and UV-B bands of natural sunlight.
During the test, the sample is placed in the test chamber, and ultraviolet radiation will cause changes in the chemical structure of the surface of the material, such as color fading, strength reduction and brittleness increase. At the same time, the test chamber can also be combined with environmental factors such as temperature and humidity for a more comprehensive evaluation of the sample. For example, the humidity control system in the laboratory can simulate the effects of rain and moisture, while the temperature control equipment can reproduce extreme hot or cold conditions.
By exposing the samples to multiple rounds of ultraviolet radiation at different time periods, researchers were able to collect a large amount of experimental data and analyze the aging resistance and service life of the samples in depth. These data play a vital role in material development, product quality control and market demand analysis. In addition, the use of UV weathering test chambers also helps companies anticipate possible performance problems before the launch of new products, so as to make timely adjustments and improvements.
Such tests are not only applicable to plastics, coatings, fibers and other materials, but also widely used in various industries such as automobiles, construction fields and even electronic products. By studying the performance of products in different climatic conditions, companies can improve the competitiveness of their products in the market, but also contribute to the environmental cause, because good weather resistance products usually mean a longer life cycle and less material waste.
In short, UV weathering test chambers play a key role in materials science and product development, not only allowing developers to better grasp material properties, but also for consumers to bring higher quality and more durable products. In the future development of science and technology, with the continuous progress of ultraviolet weathering test technology, we may be able to witness the birth of more new materials and new products, adding more convenience and beauty to our lives.
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