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GB/T 2423.4-2008 (GB/T2423.4-2008)

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GB/T 2423.4-2008: PDF in English (GBT 2423.4-2008)

GB/T 2423.4-2008
Environmental testing for electric and electronic products - Part 2. Test method - Test Db. Damp heat, cyclic (12h 12h cycle)
ICS 19.040
K04
National Standards of People's Republic of China
GB/T 2423.4-2008/IEC 60068-2-30.2005
Replace GB/T 2423.4-1993
Environmental testing of electrical and electronic products
Part 2. Test Methods Test D犫.
(IEC 60068-2-30.2005, Environmentaltesting-
Part 2-30. Tests-TestDb. Dampheat, cyclic (12h+12hcycle), IDT)
Released on.2008-05-19
2009-01-01 implementation
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
China National Standardization Administration issued
Content
Foreword III
1 range 1
2 Normative references 1
3 General Description 1
4 test box --- construction requirements 1
5 severity 2
6 initial detection 2
7 Condition test 2
8 Intermediate detection 3
9 recovery 3
10 Final test 3
11 Information to be given in the relevant specifications 3
Appendix A (informative) Guide 8
GB/T 2423.4-2008/IEC 60068-2-30.2005
Foreword
This part is the fourth part of GB/T 2423.
This part is equivalent to IEC 60068-2-30.2005 "Environmental Test Part 2-30. Test Method Test Db. Alternating Damp Heat
(12h+12h cycle)》 (English version). The main editorial changes were made as follows.
--- Removed the preface and introduction to international standards;
--- Increased the preface to national standards;
--- Citation of national standards using international standards.
This section replaces GB/T 2423.4-1993, and the main differences are.
--- Figure 2 is changed to Figure 2a) and Figure 2b);
--- In the cooling phase, Method 2 allows for greater tolerances for relative humidity and temperature drop rates;
---Recovery condition Relative humidity changed from "(75±3)%" to "(75±2)%", and the temperature was changed from "laboratory temperature ±2K"
"Laboratory temperature ± 1K";
--- Added Appendix A.
Appendix A of this section is an informative annex.
This part is proposed and managed by the National Technical Committee for Environmental Conditions and Environmental Testing Standardization of Electrical and Electronic Products.
This section drafted by. China Electric Apparatus Research Institute, Shanghai Industrial Automation Instrumentation Institute.
The main drafters of this section. Yan Jinglian, Wang Jie.
The previous versions of the standards replaced by this part are. GB/T 2423.4-1981, GB/T 2423.4-1993.
GB/T 2423.4-2008/IEC 60068-2-30.2005
Environmental testing of electrical and electronic products
Part 2. Test Methods Test D犫.
1 range
This section applies to the determination of components, equipment or other products in combination with high humidity and temperature cycling and is usually on the surface of the test specimen.
Adaptability for use, transport and storage under conditions of condensation. If this test is used to test the packaged samples during transportation and storage
The performance should be tested together with the package.
For small, lightweight samples, it may be difficult to produce condensation on the surface of the sample; users should consider using other
Generation test, such as GB/T 2423.34-2005.
2 Normative references
The terms in the following documents become the provisions of this part by reference to this part of GB/T 2423. Quotations with dated
And all subsequent amendments (not including errata content) or revisions do not apply to this section, however, encouragement is achieved in accordance with this section.
The parties to the agreement study whether the latest versions of these documents can be used. For undated references, the latest edition applies to this
section.
GB/T 2421-1999 Environmental testing of electrical and electronic products - Part 1. General (idt IEC 60068-1.1988)
GB/T 2422-1995 Environmental test terminology for electrical and electronic products (eqv IEC 60068-5-2.1990)
GB/T 2423.34-2005 Environmental testing for electric and electronic products - Part 2. Test methods Test Z/AD. Temperature/Humidity
Combined cycle test (IEC 60068-2-38. 1974, IDT)
GB/T 2424.6-2006 Environmental testing of electrical and electronic products Temperature/humidity test chamber performance verification (IEC 60068-3-6.2001,
IDT)
3 General instructions
This test involves one or more temperature cycles in which the relative humidity is maintained at a higher level.
This section gives two cycles, except that the cooling phase is different, the rest is exactly the same; in the cooling phase, Method 2 allows relative
Humidity and temperature drop rates have large tolerances.
The upper limit of the temperature cycle and the number of cycles (see Chapter 5) determine the severity of the test.
The test process is shown in Figure 1, Figure 2a), Figure 2b) and Figure 3.
The tolerances described in this section do not take into account measurement uncertainty.
4 test box --- construction requirements
4.1 The temperature can be cyclically varied between 25 °C ± 3K and the specified high temperature, and its tolerance and rate of change are in accordance with 7.3, Figure 2a) or Figure 2b)
Provisions.
The total temperature tolerance of ±3K takes into account the absolute error of the measurement, the slow change in temperature and the temperature change in the workspace.
definite. However, in order to maintain the relative humidity within the specified tolerance, the temperature difference between any two points in the workspace at any time
Must be maintained in a small range. If the temperature difference exceeds 1K, the humidity condition will not meet the requirements. In order to maintain the specified humidity,
Short-term temperature fluctuations must be maintained within ±0.5K.
4.2 The relative humidity of the workspace can be kept within the limits given in 7.3 Figure 2a) or Figure 2b) (when applicable).
GB/T 2423.4-2008/IEC 60068-2-30.2005
4.3 Pay attention to ensure that the conditions in the working space of the box are uniform, and the conditions near the appropriate temperature and humidity sensing device should be as
Close. The test chamber shall meet the corresponding performance requirements in GB/T 2424.6-2006.
4.4 The test sample should not be affected by the thermal radiation from the test chamber conditioning process.
4.5 The water used to maintain the humidity in the tank shall have a resistivity of not less than 500 Ωm.
The condensed water in the tank should be discharged in time and should not be used before purification.
Measures should be taken to ensure that condensate does not drip onto the test sample.
4.6 The size, nature or electrical load of the test sample is not allowed to significantly affect the conditions in the tank.
5 severity
5.1 The combination of high temperature and number of cycles determines the severity of the test.
5.2 The severity should be selected from the following values.
a) High temperature. 40 ° C; number of cycles. 2, 6, 12, 21, 56.
b) High temperature. 55 ° C; number of cycles. 1, 2, 6.
6 initial detection
Test samples shall be visually inspected for electrical and mechanical properties in accordance with relevant standards.
7 Conditional test
Test samples shall be placed in the test chamber without being packaged, energized, ready for use or in accordance with other regulations of the relevant standards.
If a specific mounting bracket is not specified, the heat transfer of the mounting bracket should be as low as possible, so that virtually all test samples are absolutely
hot.
7.1 Temperature tolerance
The total temperature tolerance of ±2K or ±3K takes into account the absolute error of the measurement, the slow change in temperature and the temperature in the workspace.
Determined by the degree of change. However, in order to maintain the relative humidity within the specified tolerance range, between any two points in the workspace at any time.
The temperature difference must be maintained within a small range. If the temperature difference exceeds 1K, the humidity condition will not meet the requirements. In order to maintain the rules
The humidity should be maintained at ±0.5K for short-term fluctuations.
7.2 Stability period
The temperature of the test sample should be stable at 25 °C ± 3K (GB/T 2421-1999 and GB/T 2422-1995 give temperature stability
Definition). Stabilization is achieved by.
a) Place the test sample in another box before placing the test sample in the test chamber, or,
b) After placing the test sample into the test chamber, adjust the temperature of the chamber to 25 °C ± 3K and keep it until the test sample reaches temperature stability.
Regardless of the method used, the relative humidity during the temperature stabilization period must be within the limits of the specified standard atmospheric conditions for the test.
Within the value.
After the sample is stabilized in the test chamber, the relative humidity inside the chamber should rise to not less than 95% and the ambient temperature is 25 °C ± 3K.
7.3 24-hour cycle
7.3.1 The temperature inside the tank should be raised to the appropriate high temperature value specified in the relevant standards. High temperature should be reached within 3h±30min, and its temperature rise rate
The rate should be kept within the bounds of the shaded areas in Figures 2a) and 2b).
The relative humidity at this stage should be no less than 95%, and the relative humidity within the last 15 minutes should be no less than 90%.
Condensation may occur on the test sample during the rising temperature phase.
Note. The presence of condensation conditions means that the surface temperature of the test sample is below the air dew point temperature inside the chamber.
7.3.2 The temperature shall be maintained within ±2K of the specified high temperature limit until 12h ± 30min from the start of the cycle.
During the first and last 15 minutes of this phase, the relative humidity should be between 90% and 100%, and the relative humidity should be (93 ± 3)% for the rest of the period.
7.3.3 Temperature can be reduced by one of the two methods given below.
GB/T 2423.4-2008/IEC 60068-2-30.2005
Method 1 (see Figure 2a))
The temperature should drop to 25 °C ± 3K within 3h ~ 6h. The cooling rate at the initial 1.5h should be as shown in Figure 2a) within 3h ± 15min
The temperature reached 25 ° C ± 3K. In the first 15 minutes, the relative humidity should be not less than 90%, and the relative humidity during the rest of the time should be not less than 95%.
Note. The applicable sample description for Method 1 is given in Appendix A.
Method 2 (see Figure 2b))
The temperature should drop to 25 °C ± 3K within 3h ~ 6h, but there is no additional requirement for the first 1.5h in Type 1. Relative humidity should not be less than
80%.
Note. The applicable sample description for Method 2 is given in Appendix A.
7.3.4 The temperature should be maintained at 25 °C ± 3K, while the relative humidity is not less than 95%, until the end of a cycle of 24 hours.
8 intermediate detection
The relevant standards may require performance testing during the conditional test.
Note. Measurements taken before the recovery test samples are taken out of the box and are not allowed in the condition test. If you want to make an intermediate measurement, then
The standard shall specify the measurement item and which stage of the conditional test period to follow.
9 recovery
The relevant standards should specify whether the recovery process is under standard atmospheric conditions for testing (5.3 of GB/T 2421-1999) or controlled
Under the recovery conditions (5.4.1 in GB/T 2421-1999).
If controlled recovery conditions are required (see Figure 3), the test sample can be transferred to another tank or left in a wet heat box.
restore.
In the former case, the conversion time should be as short as possible and should not exceed 10 minutes.
In the latter case, the relative humidity is reduced to (75 ± 2)% within 1 h, and then the temperature is adjusted to the laboratory temperature for another 1 h.
Degree ± 1K. For large test samples, the relevant standards allow for longer conversion times.
The calculation of the recovery time (1h to 2h) is calculated from the time when the specified recovery condition is reached.
If the test sample has a large thermal time constant, it is allowed to have a sufficient temperature to stabilize (GB/T 2421-1999)
The recovery period in Chapter 4).
The relevant standards should state whether any special measures are required to remove moisture from the surface of the test sample.
10 final inspection
Samples should be visually inspected and performance tested in accordance with relevant specifications.
Measurements should be taken immediately after the end of the recovery period and the parameters most sensitive to relative humidity are measured first. Unless there are relevant regulations
The measurement of all parameters should be completed within 30 minutes.
11 Information to be given in the relevant specifications
When the test is included in the relevant specification, the following information should be provided as much as possible.
Terms
a) Severity. temperature and cycle times 5.2
b) Initial inspection Chapter 5
c) Status of the sample in the conditional test Chapter 7
d) Case of mounting bracket or support Chapter 7
e) Method 1 or Method 2 7.3.3
f) Intermediate Inspection Chapter 8
g) Recovery conditions Chapter 9
GB/T 2423.4-2008/IEC 60068-2-30.2005
h) Measures taken to remove surface moisture Chapter 9
i) Visual inspection and performance test after the end of the test, which should be measured first
The parameter, which ultimately measures the maximum time allowed for all parameters. Chapter 10
Figure 1 Test D犫---stability phase
GB/T 2423.4-2008/IEC 60068-2-30.2005
Figure 2犪) Test D犫---Test Cycle---Method 1
GB/T 2423.4-2008/IEC 60068-2-30.2005
Figure 2犫) Test D犫---Test Cycle---Method 2
GB/T 2423.4-2008/IEC 60068-2-30.2005
Figure 3 Test D犫---Recovery under controlled conditions
GB/T 2423.4-2008/IEC 60068-2-30.2005
Appendix A
(informative appendix)
Guidelines
Two methods of cooling are provided in this test.
Method 1, starting 90 minutes, the rate of temperature drop should be strictly controlled, the relative humidity should not be lower than 95%, except for the first 15 minutes.
Less than 90%. This method requires a special test chamber.
Method 1 is particularly suitable for samples that are wetted by moisture due to respiration, such as samples that form a condensation inside the inner surface.
Method 2 has good reproducibility for other samples.
Further information on the damp heat test including steady state and alternating tests can be obtained from GB/T 2424.2-2005.
GB/T 2423.4-2008/IEC 60068-2-30.2005
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Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.