GB/T 2423.27-2020Environmental testing - Part 2: Test methods - Test method and guidance: Combined temperature or temperature and humidity with low air pressure tests (English PDF)

Preface

GB/T 2423 "Environmental Testing Part 2.Test Methods" is divided into several parts according to the test methods.

Refer to Appendix NA for the components of GB/T 2423.

This part is part 27 of GB/T 2423.

This section was drafted in accordance with the rules given in GB/T 1.1-2009.

This part replaces GB/T 2423.25-2008 "Environmental Testing of Electrical and Electronic Products Part 2.Test Method Test Z/AM. Low

Temperature/low pressure comprehensive test", GB/T 2423.26-2008 "Environmental test of electrical and electronic products Part 2.Test method test Z/

BM. High temperature/low air pressure comprehensive test and GB/T 2423.27-2005 "Environmental testing of electrical and electronic products Part 2.Test methods

Test Z/AMD. Low temperature/low air pressure/humid heat continuous comprehensive test".

Compared with GB/T 2423.25-2008, GB/T 2423.26-2008 and GB/T 2423.27-2005, the main technical changes in this part are as follows.

---Combined the main technical aspects of GB/T 2423.25-2008, GB/T 2423.26-2008 and GB/T 2423.27-2005

Content and rearrange the structure of this part;

--- Deleted the "general description of the test", "description of the test equipment" and other aspects;

--- Deleted the distinction between heat dissipation test samples and non-heat dissipation test samples in the test;

---Added Appendix A "Temperature/Low Pressure or Temperature/Humidity/Low Pressure Comprehensive Test Guide".

The translation method used in this part is equivalent to the use of IEC 60068-2-39.2015 Environmental Testing Part 2-39.Test Test Methods and Guidance

Then. temperature/low pressure or temperature/humidity/low pressure comprehensive test".

The Chinese documents that have a consistent correspondence with the international documents cited in this section are as follows.

---GB/T 2421-2020 Environmental Test Overview and Guidelines (IEC 60068-1.2013, IDT)

---GB/T 2423.3-2016 Environmental Test Part 2.Test Method Test Cab. Constant Humidity Test (IEC 60068-

2-78.2012, IDT)

Compared with IEC 60068-2-39.2015, this part mainly makes the following editorial changes.

---The name of this part is changed to "Environmental Testing Part 2.Test Methods, Test Methods and Guidelines. Temperature/Low Pressure or Temperature/Humidity

Degree/low air pressure comprehensive test";

---Informative appendix NA "Components of GB/T 2423" has been added.

This part is proposed and managed by the National Standardization Technical Committee on Environmental Conditions and Environmental Tests for Electrical and Electronic Products (SAC/TC8).

Drafting organizations of this section. China Electrical Equipment Research Institute Co., Ltd., Shenzhen Urit Testing Technology Co., Ltd., AVIC Great Wall

Metrology and Testing (Tianjin) Co., Ltd., Guangzhou Power Supply Bureau Co., Ltd. Electric Power Test Research Institute, Wuxi Soyat Test Equipment Co., Ltd., Jiangsu

Topmilo Environmental Testing Equipment Co., Ltd., Nanjing Wuhe Testing Equipment Co., Ltd., Chongqing Hongrui Testing Instrument Co., Ltd., Guangdong Midea Health

Huo Electric Manufacturing Co., Ltd., Bell Laboratory Equipment Jiangsu Co., Ltd., Zhejiang Institute of Metrology, Fujian Xinneng Offshore Wind Power Research Institute

Development Center Co., Ltd., Shanghai Institute of Metrology and Testing Technology, Shenzhen Institute of Metrology and Quality Inspection, Ningbo Chinese Academy of Sciences Information Technology

Applied Research Institute.

introduction

When exposed to different natural environmental conditions, the performance of equipment and components should not cause serious deterioration. For example, temperature, humidity, low

Air pressure synthesis may only have a certain effect on components and gaskets.

The types and severity of environmental parameters depend on the operating, transportation, and storage environments exposed to equipment and components. Environmental impact on equipment performance

It is very different in the tropics and humid tropics and the Arctic. Different environmental parameters will cause various or overlapping effects on equipment and components.

Added effect.

Manufacturers try to ensure that, at the same time, users also hope that equipment and components can withstand the impact of the environment during the service life. Can be passed

The test samples are exposed to a laboratory that simulates a series of environmental parameters to test whether the equipment meets this expectation. Usually by raising the ring

The severity of the environmental parameters can achieve meaningful results in a relatively short period of time. This can be used to evaluate similar actual environmental conditions.

Environmental testing Part 2.Test methods

Test methods and guidelines. temperature/low pressure or

Temperature/humidity/low air pressure comprehensive test

1 Scope

This part of GB/T 2423 gives the test methods for the temperature/low pressure or temperature/humidity/low pressure comprehensive test of equipment or components.

Law and its guidelines.

The purpose of the comprehensive test is to study the influence of temperature/low pressure or temperature/humidity/low pressure comprehensive test on equipment or components.

Comprehensive test methods are used to evaluate electrical properties, mechanical properties or other physical properties.

2 Normative references

The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this article

Pieces. For undated references, the latest version (including all amendments) applies to this document.

IEC 60068-1 Environmental Testing Part 1.Overview and Guidelines

IEC 60068-2-78 Environmental Test Part 2-78.Test Test Cab. Constant Damp Heat

3 Terms and definitions

no.

4 Test method

5 Final inspection

The test sample shall be inspected for appearance, size and function according to relevant specifications.

The relevant specifications shall provide the basis for whether the test sample passes the test.

6 Information that should be given by relevant specifications

The relevant specifications should at least give the following information.

a) Test time;

b) Temperature at low pressure;

c) Low pressure value;

d) The temperature value when determining the humidity;

e) humidity value;

f) Type of test procedure;

h) Type and scope of initial testing;

i) Type and scope of intermediate testing;

j) recovery;

k) The type and scope of the final inspection;

l) Test criteria;

m) Type and scope of test report.

7 Information to be given in the test report

The test report should contain at least the following information.

a) Customer (name and address);

b) Testing laboratory (name and address, accreditation details, if any);

c) Test date (date when the test was conducted);

d) Test type (e.g. temperature/low pressure, temperature/humidity/low pressure);

e) Test requirements (temperature, low air pressure, etc.);

f) Test purpose (R&D, identification, etc.);

g) Test standard and version (GB/T 2423.27, version used);

h) Related laboratory test procedures (code and issue number);

i) Description of test samples (drawings, photos, quantity, composition status, etc.);

j) Test box (manufacturer, model, unique code, etc.);

k) Test equipment performance (set point temperature control, etc.);

l) Wind speed and direction (air speed and direction of air flow blowing towards the test sample);

m) Uncertainty of the measurement system (uncertainty data);

n) Calibration date (the date of the last calibration and the next calibration);

o) Initial, intermediate and final inspections (initial, intermediate and final inspections);

p) The required severity level (obtained from relevant specifications);

q) Actual test conditions (measurement points, data, etc.);

r) The performance of the test sample (function test results, etc.);

s) Observations and measures taken during the test (any relevant observations);

Appendix A

(Informative appendix)

Temperature/low pressure or temperature/humidity/low pressure comprehensive test guide

A.1 Overview

Based on the parts of the IEC 60068-2 series, this appendix provides basic tests for temperature/low pressure, temperature/humidity/low pressure comprehensive tests

evaluation of.

For the purpose of comprehensive testing, IEC 60068-1 should be used together with the preferred severity levels listed in the IEC 60068-2 series.

A.2 Environmental effects

A.2.1 The temperature/low pressure comprehensive test generally has the following effects on the test sample.

a) Compared with the specified value, the change of the surface temperature and temperature gradient of the heat dissipation sample is caused by the decrease of the convection coefficient under low air pressure.

Into. Although the surface temperature can be increased by using a higher test temperature under normal air pressure, this test

The temperature value cannot be determined, and the correct temperature gradient cannot be achieved without the combination of low air pressure.

b) Low pressure gas and changes in air dielectric properties cause changes in the function and safety performance of the test sample. Under low pressure, special

Especially when combined with high temperature, the dielectric strength of the air is significantly reduced, resulting in an increased risk of arcing, surface or corona discharge.

c) The change in material properties caused by low or high temperature increases the risk of deformation or rupture of sealed equipment or components under low air pressure.

A.2.2 Mainly caused by temperature, the effect of significant acceleration due to low air pressure is.

a) As the mechanical and electrical properties of each part of the test sample change, plasticizers and plastic degradation products volatilize. These volatile

The product can condense on nearby surfaces and/or produce changes in characteristics, corrosion and/or degradation.

b) Evaporation of lubricant may block moving parts.

c) Dissolved gas escapes from the liquid. The reduced low air pressure may cause a brief boiling and may leak the liquid.

A.3 Temperature measurement

The decrease in convection coefficient due to low air pressure makes the heat exchange efficiency of the gas in the box and the thermometer sensor element for temperature monitoring

reduce.

therefore.

---The response time of the thermometer to temperature changes is greater than normal pressure;

---The thermometer is more sensitive to the heat radiation of the sample.

In response to these consequences, a shield can be placed between the thermometer and the test sample to reduce the effect of thermal radiation. To compensate for temperature

The response time of the meter may require a longer measurement time.

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