GB/T 2423.50-2012 PDF in English
GB/T 2423.50-2012 (GB/T2423.50-2012, GBT 2423.50-2012, GBT2423.50-2012)
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| GB/T 2423.50-2012 | English | 210 |
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Environmental testing - Part 2: Test methods - Test Cy: Damp heat, steady state, accelerated test primarily intended for components
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| GB/T 2423.50-1999 | English | 359 |
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Environmental testing for electric and electronic products - Part 2: Tests - Test Cy: Damp heat, steady state, accelerated test primarily intended
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Standards related to (historical): GB/T 2423.50-2012
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GB/T 2423.50-2012: PDF in English (GBT 2423.50-2012) GB/T 2423.50-2012
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 19.040
K 04
GB/T 2423.50-2012 / IEC 60068-2-67:1995
Environmental testing - Part 2: Test methods - Test Cy:
Damp heat, steady state, accelerated test primarily
intended for components
(IEC 60068-2-67:1995, Environmental testing – Part 2: Tests – Test Cy:
Damp heat, steady state, accelerated test primarily intended for
components, IDT)
ISSUED ON: NOVEMBER 05, 2012
IMPLEMENTED ON: FEBRUARY 01, 2013
Issued by: General Administration of Quality Supervision, Inspection
and Quarantine;
Standardization Administration of the People’s Republic of
China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 General description ... 4
3 Description of test apparatus ... 4
4 Test conditions and severity level ... 5
5 Pretreatment ... 6
6 Initial measurements ... 6
7 Condition test ... 6
8 Intermediate measurements ... 7
9 Recovery ... 8
10 Final measurements ... 8
11 Information to be given in the relevant specification ... 8
Appendix A (Informative) Physical meaning of the experiment ... 9
Appendix B (Informative) Test equipment and its management ... 10
Appendix NA (Informative) Parts of the standard GB/T 2423 ... 12
Environmental testing - Part 2: Test methods - Test Cy:
Damp heat, steady state, accelerated test primarily
intended for components
1 Scope
This Part of GB/T 2423 specifies test methods to evaluate the effect of damp
heat resistance of small electric and electronic products (mainly non-airtight
components) in an accelerated manner.
This test does not apply to the evaluation of external effects such as corrosion
and deformation.
2 General description
In this test, the sample withstands a high unsaturated damp heat steam
pressure for a long period of time.
Usually apply a bias voltage.
This test provides a variety of preferred test durations under the conditions of a
relative humidity of 85% and a temperature of 85°C.
As far as plastic-packaged components are concerned, the degradation is
caused by the absorption of water vapor by the plastic and the penetration of
water vapor along the leading-out terminal.
3 Description of test apparatus
3.1 Test chamber
The parameters of the test chamber shall meet the following requirements:
a) It shall meet the temperature and relative humidity conditions that are
given in Table 1, and keep at least 2 000 h uninterrupted;
b) During the test, it shall be able to provide controlled temperature and
humidity conditions, and be able to increase and decrease the
temperature according to the specified conditions;
c) The temperature and humidity in the test chamber shall be detected by a
sensing apparatus that is placed in the work space or/and other areas that
can give the same result;
d) All water in the work space shall be drained continuously and cannot be
reused;
e) Condensed water is not allowed to fall on the test sample;
f) The structural material of the box wall shall not cause obvious corrosion of
the test sample or reduce the quality of humidifying water (see Appendix
B.1).
The temperature tolerance of ±2K takes into account the absolute error of the
measurement, the temperature fluctuation at any point in the work space, and
the temperature difference between any two points.
However, in order to maintain the relative humidity within the specified tolerance
zone of ±5%, the temperature difference between any two points in the work
space (at any time) shall be kept within a smaller range.
If this temperature difference exceeds 1.5 K, the specified humidity tolerance
will be out of tolerance. Therefore, it is also necessary to limit the short-term
temperature fluctuation that is caused by the periodic heating of the test
chamber heater to a similar value.
The test sample shall not obstruct the air flow significantly.
No condensation is allowed to form on the sample at any time during the test.
3.2 Water for humidification
Distilled or deionized water shall be used. When the water is at 23 °C, the
resistivity shall not be less than 0.5 MΩ·cm, and the pH value shall be at 6.0 ~
7.2.
Before putting water into the humidifier, clean the internal parts of the test
chamber. Cleaning guidelines are given in Appendix B.3.
After each test, all the water in the humidifier and the test box shall be removed.
4 Test conditions and severity level
In this Part, the test severity level is determined by the duration of the test.
Unless otherwise specified, the severity level shall be selected from the
durations that are given in Table 1.
7.3 If it is required by the relevant standards, a bias voltage shall be applied to
the test sample during the test. The guidelines for applying the bias voltage are
given in Appendix B.2.
The bias voltage (or bias cycle) shall be applied to the test sample when the
temperature and relative humidity reach a stable state, and continuously
applied until the test sample is in the recovery condition.
7.4 Test cycle
7.4.1 Raise the temperature and relative humidity of the test chamber to an
appropriate value. During this period, the temperature and relative humidity
shall not exceed the specified limits. During the test, no condensed water is
allowed on the test sample, and the temperature and humidity shall be stable
within 3 h.
7.4.2 During the duration that is specified in the relevant standards, the
temperature and relative humidity shall be maintained within the specified range.
The duration of the test shall be calculated as soon as the test conditions are
stabilized.
7.4.3 After the specified test time is over, the temperature and relative humidity
of the test chamber shall be restored to the standard atmospheric conditions for
measurement and testing within 1 h ~ 4 h.
7.4.4 During this period, the temperature and relative humidity shall not exceed
the specified values, and the bias voltage shall be maintained.
7.4.5 Once the cooling phase is over, the sample shall enter the recovery
procedure.
8 Intermediate measurements
Relevant standards may require electrical and/or mechanical performance
measurement during the test.
If intermediate measurements are required, the relevant standards shall specify
the test items and the stage at which these tests shall be carried out, but these
measurements shall not cause any changes in the test conditions.
During the test, it is not allowed to move the test sample out of the test chamber
for post-recovery measurement.
Appendix B
(Informative)
Test equipment and its management
B.1 Selection of materials
Careful selection of the materials which are used in the test chamber will
significantly reduce the release of pollutants and the degradation due to
corrosion and other mechanical reasons. These are all produced under the
comprehensive conditions of temperature and humidity specified in this test.
Suitable materials are: stainless steel, glass, ceramics and other corrosion-
resistant materials.
B.2 Bias voltage
The definition of bias voltage is to enhance the humidity effect; the voltage that
is applied for the purpose of the test is not necessarily related to the normal
function of the test sample.
The bias voltage shall be applied according to the following guidelines (the
following points are arranged in order of decreasing importance):
a) After the bias voltage is applied, the difference BETWEEN the temperature
of each specified point inside and on the surface of the sample in the work
space AND the nominal temperature shall be less than 2 K;
b) When selecting the bias voltage, attention shall be paid to not only
promoting the hydrolysis, but also limiting the self-heating of the test
sample, because self-heating will affect the penetration and/or absorption
of water. When the continuous application of a bias voltage cannot prevent
significant self-heating, it is recommended to apply the bias voltage
intermittently; unless otherwise specified, the period of applying the bias
voltage is: no bias voltage is applied for 3 hours; a bias voltage is applied
for 1 hour; the bias voltage is never applied;
c) Precautions shall be taken to limit energy loss due to fault conditions.
Note: Applying a bias voltage to the test sample under constant relative
humidity conditions can enhance various effects that are induced by
water vapor. In addition, the bias voltage will cause power dissipation,
which has the opposite effect to the purpose of the test, because it will
cause a local temperature increase and thereby reduce the relative
humidity of the critical position.
B.3 Cleaning
......
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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