GB/T 2423.22-2012 PDF in English
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GB/T 2423.22-2012: PDF in English (GBT 2423.22-2012) GB/T 2423.22-2012
Environmental testing.Part 2. Test methods.Test N. Change of temperature
ICS 19.040
K04
National Standards of People's Republic of China
Replace GB/T 2423.22-2002, GB/T 2424.13-2002
Environmental testing - Part 2. Test methods
Test N. temperature change
Environmentaltesting-Part 2. Testmethods-
TestN. Changeoftemperature
(IEC 60068-2-14.2009, Environmentaltesting-
Part 2-14. Tests-TestN. Changeoftemperature, IDT)
Released on.2012-12-31
2013-06-01 implementation
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
China National Standardization Administration issued
Content
Foreword I
Introduction III
1 range 1
2 Normative references 1
3 Field conditions of temperature change 1
4 General 1
4.1 Design of temperature change test 1
4.2 Test parameters 2
4.3 Purpose of the test and test method selection 2
4.4 Choice of exposure duration 2
4.5 Conversion time selection 2
4.6 Application Limits for Temperature Change Tests 3
5 Test Type Selection Guide 3
6 initial detection and final detection 3
6.1 Initial detection 4
6.2 Final detection 4
7 Test Na. Specify a rapid temperature change for the transition time 4
7.1 Test Overview 4
7.2 Test procedure 4
7.3 Recovery 5
7.4 Information to be given in the relevant specifications 5
8 Test Nb. temperature change specifying the rate of change 6
8.1 Test Overview 6
8.2 Test procedure 6
8.3 Recovery 7
8.4 Information to be given in the relevant specifications 7
9 Test Nc. two liquid tank method rapid temperature change 8
9.1 Test Overview 8
9.2 Test procedure 8
9.3 Recovery 9
9.4 Information to be given in the relevant specification 9
10 Information to be given in the test report 9
Appendix NA (informative) Part of the GB/T 2423 standard 11
Foreword
This part is the 22nd part of the GB/T 2423 standard. The components of the GB/T 2423 standard are listed in the informative appendix NA.
This part is drafted in accordance with the rules given in GB/T 1.1-2009.
This part replaces GB/T 2423.22-2002 "Electrical and Electronic Products Environmental Test Part 2. Test Method Test N. Temperature
"Changes" and GB/T 2424.13-2002 "Electrical and Electronic Products Environmental Testing Part 2. Test Methods Temperature Change Test Guide".
This part is mainly based on GB/T 2423.22-2002, which integrates part of GB/T 2424.13-2002 with GB/T 2423.22-
In.2002, compared with GB/T 2424.13-2002, the main technical changes and editorial changes are as follows.
--- Test Na and test Nb, remove the relevant requirements for absolute humidity, tank wall temperature and air flow rate of the test chamber (see
7.2.1, 8.2.1);
--- Test Na, the provisions of the test chamber allowed to use a rapid temperature change rate are increased (see 7.2.1);
--- Test the severity of the Na and test Nb, increasing the "exposure duration" parameter (see 7.2.3, 8.2.3);
--- Test Na, deleted the "conversion time should be. (2 ~ 3) min, (20 ~ 30) s, < 10s" provisions, replaced by "conversion time
T2 should not exceed 3 minutes" (see 7.2.5);
--- Test Nb, increased two preferred values of temperature change rate. (10 ± 2) K/min and (15 ± 3) K/min (see 8.2.3);
--- Test Nc, deleted two sets of standardized duration parameters;
--- The unit of temperature deviation replaces "°C" with "K";
--- Deleted the contents of 3.4.2 and Chapter 4 of GB/T 2424.13-2002;
--- Updated the contents of 3.3 of GB/T 2424.13-2002;
--- Updated all the diagrams;
--- Combine the contents of the test Na, the test Nb, and the test Nc "initial and final test" into a separate chapter 6;
--- Added Chapter 10 "Information to be given in the test report";
--- The structure of each chapter describing the test Na, test Nb, test Nc has been adjusted (see Chapter 7, Chapter 8, Chapter 9).
This section uses the translation method equivalent to IEC 60068-2-14.2009 "Environmental Testing Part 2-14. Test Method Test N.
temperature change".
The documents of our country that have a consistent correspondence with the international documents referenced in this part are as follows.
GB/T 2423.1 Environmental testing of electrical and electronic products - Part 2. Test methods Test A. Low temperature (GB/T 2423.1-
2008, IEC 60068-2-1..2007, IDT)
GB/T 2423.2 Environmental testing of electrical and electronic products - Part 2. Test methods Test B. High temperature (GB/T 2423.2-
2008, IEC 60068-2-2.2007, IDT)
Compared with IEC 60068-2-14.2009, this part mainly made the following editorial changes.
--- The name of this section was changed to "Environmental Test Part 2. Test Method Test N. Temperature Change";
--- In Chapter 9, the original IEC number is incorrect. In this part, the number of the item 9.3 is changed to "9.2.4", and the number of the item 9.4 is changed to "9.3".
The number of 9.5 is changed to "9.4";
--- In Figure 2, the expression in the original IEC is incorrect. This section will be two places. \u003ct1/10”改为“≤t1/10”;
--- Added the informative appendix "components of the GB/T 2423 standard" (see Appendix NA).
This part is proposed and managed by the National Technical Committee for Environmental Conditions and Environmental Testing Standardization of Electrical and Electronic Products (SAC/TC8).
This section drafted by. China Electric Apparatus Research Institute Co., Ltd., Shenzhen Institute of Metrology and Quality Inspection, Zhejiang Institute of Metrology
Research Institute, Chongqing Sida Test Equipment Co., Ltd., Beijing University of Aeronautics and Astronautics, Shanghai Industrial Automation Instrumentation Research Institute, Shanghai Quality Supervision
Institute of Technology.
The main drafters of this section. Zhang Zhiyong, Zhu Jianhua, Zhang Hongyu, Chen Yunsheng, Yao Jun, Hu Honghui, Lu Zhaoming.
The previous versions of the standards replaced by this section are.
---GB/T 2423.22-1981, GB/T 2423.22-1987, GB/T 2423.22-2002;
---GB/T 2424.13-1981, GB/T 2424.13-2002.
introduction
The temperature change test is used to determine the effect of one or several consecutive temperature changes on the test sample.
The temperature change test is not used to determine the effect only due to high or low temperatures. To determine such effects, high or low temperatures should be used.
test.
The effect of the temperature change test depends on.
--- The high temperature value and low temperature value of the condition test, the temperature changes between these two values;
--- The duration of the test sample at high or low temperatures;
--- The rate of change of temperature from high to low or from low to high;
---The number of cycles of the condition test;
--- Heat transferred to the test sample or heat transferred from the test sample.
The detailed specifications contain suitable test parameters, and the selection guidelines for these parameters are given in this part of GB/T 2423.
Environmental testing - Part 2. Test methods
Test N. temperature change
1 Scope
The tests specified in this part of GB/T 2423 are used to determine the ability of components, equipment or other products to withstand rapid changes in ambient temperature.
force. The duration of exposure at each temperature required to achieve this depends on the characteristics of the test sample.
2 Normative references
The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this article.
Pieces. For undated references, the latest edition (including all amendments) applies to this document.
IEC 60068 (all parts) Environmental Test (Environmental testing)
IEC 60068-2-1 Environmental test Part 2-1: Test methods Test A. Low temperature (Environmental testing-Part 2-1: Tests-TestA.cold)
IEC 60068-2-2 Environmental test - Part 2-2: Test method Test B. High temperature
IEC 60068-2-17 Environmental testing - Part 2-17: Test method test Q. Seals
3 Field conditions of temperature change
Temperature changes in electronic devices and components are common. When the device is not powered, its internal parts are on its outer surface
The parts undergo a slow temperature change.
Fast temperature changes are foreseen in the following situations.
--- When the equipment is transferred from a warm indoor environment to a cold outdoor environment, or vice versa;
--- When the equipment is exposed to rain or immersed in cold water and suddenly cooled;
---Installed in an external airborne device;
--- Under certain transportation and storage conditions.
A high temperature gradient occurs in the device after power-on, and components are subject to stress due to temperature changes, for example, beside high-power resistors
On the side, the radiation causes the surface temperature of the adjacent components to rise, while the other parts are still cold.
When the cooling system is energized, the manually cooled components experience rapid temperature changes. Can also be caused during the manufacturing process of the device
Rapid temperature change of components. The number and magnitude of temperature changes and time intervals are important.
4 General
4.1 Design of temperature change test
Tests Na, Nb, and Nc include alternating high temperature and low temperature periods, and the conversion from one temperature to another is also well defined.
From the laboratory ambient temperature to the first condition test temperature, then to the second condition test temperature, and then back to the laboratory ambient temperature
The knot process is considered a test cycle.
4.2 Test parameters
Test parameters include the following.
---Test room ambient temperature;
---high temperature;
---low temperature;
---Exposure duration;
--- Conversion time or rate of change;
---The number of test cycles.
High temperature and low temperature refer to the ambient temperature, which is reached by most test samples, but the time is delayed.
Only in exceptional cases can the high temperature or low temperature be specified for normal storage or outside the operating temperature range of the test sample.
Since the number of sudden changes in temperature during a given time is greater than the number of occurrences of field conditions, the test is accelerated.
4.3 Purpose of the test and selection of test methods
It is recommended to select the temperature change test as follows.
--- Evaluation of electrical properties under temperature changes, select test Nb;
--- Evaluation of mechanical properties under temperature changes, select test Nb;
---Evaluate the electrical performance after a specified number of rapid temperature changes, select test Na or test Nc;
---Evaluate whether the mechanical parts, materials and material combinations are suitable for withstanding rapid temperature changes, choose test Na or test Nc;
--- Evaluate whether the structure of the component is suitable for withstanding artificial stress, and choose test Na or test Nc.
The temperature change test specified in GB/T 2423 is not used to evaluate the test sample to work under two extreme conditions of extreme temperature.
Material stability or electrical performance differences.
4.4 Choice of exposure duration
The duration of exposure should be based on the requirements of 7.2.3, 8.2.3 or 9.2.2, or the requirements of the relevant specifications, pay attention to the following points.
a) Once the test sample is placed in a new environment, the exposure begins immediately.
b) When the temperature difference ΔT between the test sample and the test medium is in the range of 3K~5K, or the range specified by the test specification, the temperature is
Stable. The temperature stabilization period ts is the time from the start of exposure until the temperature reaches a prescribed temperature difference. Optional
A representative point or point on the test sample is measured.
c) The exposure duration t1 should be longer than the test sample temperature stabilization time ts. An illustration of this process is shown in Figure 1. This may not be suitable for
Fecal test sample.
4.5 Conversion time selection
In the case of the two-box method, if the conversion cannot be completed within 3 minutes due to the large sample size, then as long as the test results are not produced
Perceptible effects, increase conversion time as follows.
T2≤0.05ts
In the formula.
T2---conversion time;
Ts---The temperature stabilization time of the test sample.
Figure 1 Determination of exposure duration (t1)
4.6 Application limits for temperature change tests
Within the test sample, the rate of temperature change depends on the thermal conductivity of the test sample material, the spatial distribution of the test sample heat capacity, and the test.
Sample size.
The temperature change at a point on the surface of the test sample generally follows an exponential law. Within the large test sample, such an alternating exponential rise
And falling results in a periodic, approximately sinusoidal temperature change that is much lower than the magnitude of the alternating temperature applied.
The heat transfer mechanism between the test sample and the conditioning medium in the tank or tank should be considered. The flowing liquid causes the surface of the test sample to be very high
The rate of temperature change, while still air causes a very low rate of change.
The two-tank method (test Nc) with water as the medium of regulation should be limited to sealed test samples or test samples with water-insensitive properties.
Product, because the performance and characteristics of the test sample may be degraded by water immersion.
In certain cases, such as test samples that are sensitive to water, it is necessary to stipulate the use of other liquids that are not water for testing. When designing this test
During the inspection, it should be considered that the heat transfer characteristics of the liquid used may be different from water.
Note. The evaluation results obtained from Test Q. Seal (IEC 60068-2-17) may be helpful in evaluating the applicability of the two tank method.
5 Test Type Selection Guide
The severity of the test increases with temperature differences, rate of temperature change, and heat transfer to the test sample.
Test N is preferably used as part of the sequence test. Some types of damage may not be obvious in the final test of test N, but only
Will appear in subsequent tests (for example, Test Q. Seal, Test Fc. Vibration or Test Db. Alternating Damp Heat 1)).
The temperature change test Nc (two-tank method) should not be used instead of the test Q (sealing).
When specifying a temperature change test, attention should be paid to the characteristics of the test sample affected by temperature change conditions and their possible failure mechanisms.
Reason. The initial test and the final test should be accordingly specified accordingly.
6 initial detection and final detection
The requirements for initial and final testing of tests Na, Nb and Nc are as follows.
1) IEC 60068-2-14.2009 original text is "Test F. Vibration or Test D. Accelerated Damp Heat", but in the test method specified in IEC 60068, there is no "test"
Test D. Accelerate damp heat, "Test F" is also divided into several methods, so it is still corrected here as IEC 60068-2-33.1971.
6.1 Initial detection
The test samples shall be visually inspected and tested for electrical and mechanical properties in accordance with the relevant specifications.
6.2 Final inspection
The test samples shall be visually inspected and tested for electrical and mechanical properties in accordance with the relevant specifications.
7 Test Na. specifies the rapid temperature change of the switching time
7.1 Test Overview
This test determines the ability of components, equipment, or other products to withstand rapid changes in ambient temperature. Exposure time required to achieve this
Depends on the nature of the test sample.
The test sample shall be in a state of being unpackaged, not energized, ready for use, or otherwise specified by relevant specifications.
The test sample is exposed to rapidly changing air or a suitable inert gas and is alternately exposed to high temperatures and low temperatures.
7.2 Test procedure
7.2.1 Test box
Two separate temperature chambers or one chamber with a fast temperature change rate can be used. If you use two test chambers, one test
The test chamber is used for low temperature, one test chamber is used for high temperature, and the position of the two test chambers is such that the test sample is transferred from one test chamber to another.
The box can be completed within the specified time. Manual or automatic conversion methods can be used.
Any area in which the test sample is placed in the test chamber shall be capable of maintaining the air temperature specified in the test.
After the test sample is placed, the air temperature should reach the specified tolerance within 10% of the exposure duration.
7.2.2 Installation or support of test samples
Unless otherwise specified in the relevant specifications, the mounting or support frame should have low thermal conductivity so that the test sample is actually thermally insulated. When several
When the test sample is tested at the same time, the test sample shall be placed so that the air between the test sample, the test sample and the inner surface of the test chamber is free.
Circulation.
7.2.3 Severity rating
The severity of the test is determined by the combination of two temperatures, conversion time, exposure duration, and number of cycles.
The relevant specifications shall specify a low temperature TA and shall be selected from the test temperatures specified in IEC 60068-2-1 and IEC 60068-2-2.
The relevant specifications shall specify high temperature TB and shall be selected from the test temperatures specified in IEC 60068-2-1 and IEC 60068-2-2.
The exposure duration t1 at two temperatures depends on the heat capacity of the test sample. The duration of exposure can be 3h, 2h, 1h,
30 min, 10 min or the time specified in the relevant specifications. When the relevant specification does not specify the exposure duration, then the time is 3h.
Unless otherwise specified in the relevant specifications, the preferred number of test cycles is 5.
Note. The exposure time of 10 min is suitable for the test of small test samples.
7.2.4 Conditional test initial state
The temperature in the test sample and test chamber shall be at the laboratory ambient temperature, 25 ° C ± 5K. If the relevant specifications require, the test sample should be made
The product begins to enter the running state.
7.2.5 Test cycle
The test sample was exposed to a low temperature TA.
The temperature TA should be maintained for the specified time t1. T1 includes the temperature stabilization time of the air in the tank, which is no longer than 0.1 t1 (see 7.2.1).
Note 1. The duration of exposure is calculated from the moment the test sample is placed in the temperature chamber.
The test sample is then switched to exposure to high temperature TB, and the conversion time t2 should not exceed 3 minutes.
T2 shall include the time from which the test sample is removed from one test chamber, the time it is placed in the second test chamber, and the ambient temperature at the test chamber.
The time of stay.
Note 2. For high quality test samples, the conversion time from one test chamber to another can be increased according to the relevant standards or specifications.
The temperature TB should be maintained for the specified time t1. T1 includes the temperature stabilization time of the air in the tank, which is no longer than 0.1 t1 (see 7.2.1).
Note 3. The duration of exposure is calculated from the moment the test sample is placed in the temperature chamber.
For the next cycle, the test sample should be switched to exposure to low temperature TA, and the conversion time t2 should not exceed 3 min.
The first cycle includes 2 exposure times t1 and 2 conversion times t2 (see Figure 2).
At the end of the last cycle, the test sample should be subjected to a recovery procedure.
Description.
A---the first cycle begins;
B---The first cycle ends and the second cycle begins.
Note 1. The dotted line has been explained before.
IEC TC104 has been confirmed and corrected here.
Figure 2 Na test cycle
7.3 Recovery
At the end of the test cycle, the test sample shall be held for a sufficient period of time under test standard atmospheric conditions to achieve temperature stability.
For a particular type of test sample, the relevant specification can specify a specific recovery time.
7.4 Information to be given in the relevant specifications
When the relevant specification contains this test, any of the following applicable details should be given.
a) type of test;
b) pretreatment;
c) initial detection;
d) installation and support details;
e) low temperature TA, high temperature TB;
f) exposure duration t1;
g) the number of cycles;
h) detection and/or load during the conditional test;
i) recovery;
j) final detection;
k) Any deviation from the program agreed between the customer and the supplier.
8 Test Nb. temperature change specifying the rate of change
8.1 Test Overview
This test determines the tolerance and normal function of components, equipment or other products under ambient temperature changes.
The test sample shall be in a state of being unpackaged, not energized, ready for use, or otherwise specified by relevant specifications.
The test sample is exposed to temperature-changing air in the test chamber, the test chamber is maintained at the specified temperature value, and is controlled at a controlled rate.
Chemical. The performance of the test sample can be monitored during the exposure.
8.2 Test procedure
8.2.1 Test box
The test chamber for this test shall be designed such that the temperature cycle in the work space in which the test sample is placed is operated.
a) can maintain the low temperature required by the test;
b) can maintain the high temperature required by the test;
c) The rate of change from low to high or from high to low can meet the test requirements.
8.2.2 Installation or support of test samples
Unless otherwise specified in the relevant specifications, the mounting or support frame should have low thermal conductivity so that the test sample is actually thermally insulated. When several
When the test sample is tested at the same time, the test sample shall be placed so that the air between the test sample, the test sample and the inner surface of the test chamber is free.
Circulation.
8.2.3 Severity rating
The severity of the test is determined by the combination of two temperatures, rate of temperature change, duration of exposure, and number of cycles.
The relevant specifications shall specify a low temperature TA and shall be selected from the test temperatures specified in IEC 60068-2-1 and IEC 60068-2-2.
The relevant specifications shall specify high temperature TB and shall be selected from the test temperatures specified in IEC 60068-2-1 and IEC 60068-2-2.
In the range between 90% and 10% of the test temperature difference D (= TB-TA), the tolerance of the air temperature decrease or increase rate should be within the gauge
Within 20% of the fixed rate. Unless otherwise specified in the relevant specifications, the preferred values for the rate of temperature change are.
(1±0.2) K/min;
(3±0.6) K/min;
(5±1) K/min;
(10±2) K/min;
(15 ± 3) K/min.
The exposure duration t1 at two temperatures depends on the heat capacity of the test sample. The duration of exposure can be 3h, 2h, 1h,
30 min, 10 min or the time specified in the relevant specifications. When the relevant specification does not specify the exposure duration, then the time is 3h.
Test samples shall be tested continuously for 2 cycles unless otherwise specified in the relevant specifications.
8.2.4 Conditional test initial state
The temperature in the test sample and test chamber shall be at the laboratory ambient temperature, 25 ° C ± 5K. If the relevant specifications require, the test sample should be made
The product begins to enter the running state.
8.2.5 Test cycle
The air temperature in the chamber is lowered to the specified low temperature TA at a specified rate (see Figure 3).
After the temperature in the tank has stabilized, the test sample shall be exposed to low temperature conditions for a specified time t1.
The air temperature in the chamber is then raised to the specified high temperature TB at a specified rate (see Figure 3).
After the temperature in the tank has stabilized, the test sample shall be exposed to high temperature for a specified time t1.
The air temperature in the chamber is then reduced to the laboratory ambient temperature at a specified rate, 25 ° C ± 5 K (see Figure 3).
The above process constitutes a loop.
Description.
A---The first cycle begins.
Figure 3 Nb test cycle
8.3 recovery
At the end of the test cycle, the test sample shall be held for a sufficient period of time under test standard atmospheric conditions to achieve temperature stability.
For a particular type of test sample, the relevant specification can specify a specific recovery time.
8.4 Information to be given by the relevant specifications
When the relevant specification contains this test, any of the following applicable details should be given.
a) type of test;
b) pretreatment;
c) initial detection;
d) installation and support details;
e) low temperature TA, high temperature TB;
f) exposure duration t1;
g) temperature change rate;
h) the number of cycles;
i) detection and/or load during conditional testing;
j) recovery;
k) final detection;
l) Any deviation from the program agreed between the customer and the supplier.
9 Test Nc. rapid change of temperature in two-tank method
9.1 Test Overview
This test determines the ability of components, equipment, or other products to withstand rapid temperature changes.
This test procedure results in severe thermal shock and is suitable for glass-to-metal seals and similar test specimens.
The test samples were alternately immersed in two tanks, one tank containing a low temperature TA liquid and one tank containing a high temperature TB liquid.
9.2 Test procedure
9.2.1 Test equipment
Two liquid tanks, one low temperature tank and one high temperature tank should be arranged so that the test sample can be easily immersed in the liquid tank or quickly from a liquid
The tank is switched to another tank.
The cryogenic liquid tank should be able to maintain the liquid temperature at the low temperature TA specified by the relevant regulations. If there is no specified temperature, the liquid temperature should be 0 °C.
The high temperature liquid tank should be able to keep the liquid temperature at the high temperature TB specified in the relevant regulations. If there is no specified temperature, the temperature of the liquid should be
100 ° C.
The structure of the liquid tank should be such that the temperature rise of the low temperature liquid tank should not exceed 2K of TA at any time of the test, and the high temperature liquid tank
The temperature drop should not be lower than 5K of TB.
The liquid used in the test shall be compatible with the materials and protective layers used in the manufacture of the test sample.
Note. The heat transfer rate depends on the liquid used and affects the severity of the test for a given temperature range. In special cases, relevant specifications should be specified
The liquid used.
9.2.2 Severity rating
The severity of the test is determined by the specified two tank temperatures, the transition time t2 from one tank to the other, and the number of cycles.
The relevant specification should specify the duration parameter used and the selected value of t1.
The number of test cycles is 10 unless otherwise specified in the relevant specifications.
9.2.3 Conditional test initial state
Test samples should be tested without packaging.
9.2.4 Test cycle
The test sample at the laboratory ambient temperature is immersed in a cryogenic liquid tank, and the liquid temperature in the tank is the temperature TA specified by the relevant specification.
The test sample shall be kept submerged in the cryogenic tank for the time t1 specified.
The test sample is then removed from the cryogenic liquid tank and immersed in a high temperature liquid bath in which the liquid temperature is the temperature TB specified in the relevant specification.
The conversion time t2 shall comply with the relevant specifications.
The test sample shall be kept submerged in the high temperature bath for the time t1 specified.
The test sample is then removed from the high temperature bath. The conversion time t2 of the test sample taken out of the high temperature liquid tank and immersed in the low temperature liquid tank
Should comply with the relevant regulations.
One cycle consists of 2 immersion times t1 and 2 conversion times t2 (see Figure 4).
At the end of the last cycle, the test sample should be subjected to a recovery procedure.
Description.
A---The first cycle begins.
Figure 4 Nc test cycle
9.3 Recovery
At the end of the test cycle, the test sample should be kept at the laboratory ambient temperature. The droplets should be removed. If you need to clean, ...
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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