HOME   Cart(0)   Quotation   About-Us Tax PDFs Standard-List Powered by Google www.ChineseStandard.net Database: 189760 (30 Nov 2024)

GB/T 2423.59-2008 PDF in English


GB/T 2423.59-2008 (GB/T2423.59-2008, GBT 2423.59-2008, GBT2423.59-2008)
Standard IDContents [version]USDSTEP2[PDF] delivered inName of Chinese StandardStatus
GB/T 2423.59-2008English280 Add to Cart 0-9 seconds. Auto-delivery. Environmental testing - Part 2: Test methods - Test Z/ABMFh: Combined temperature (cold and heat) / low air pressure / vibration (random) Valid
Standards related to (historical): GB/T 2423.59-2008
PDF Preview

GB/T 2423.59-2008: PDF in English (GBT 2423.59-2008)

GB/T 2423.59-2008 GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA ICS 19.020 K 04 Environmental testing for electric and electronic products - Part 2: Test methods - Test Z/ABMFh: Combined temperature (cold and heat)/low air pressure/vibration (random) ISSUED ON: DECEMBER 30, 2008 IMPLEMENTED ON: NOVEMBER 01, 2009 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 Normative references ... 4 3 Terms and definitions ... 5 4 General description ... 5 5 Test equipment ... 5 6 Installation of test specimens ... 6 7 Severities ... 6 8 Pretreatment ... 9 9 Initial inspection ... 9 10 Testing ... 9 11 Intermediate inspection ... 11 12 Recovery ... 11 13 Final inspection ... 12 14 Failure criteria ... 12 15 Information to be provided in relevant specification... 12 Annex A (informative) Guidelines ... 15 Annex B (informative) Parts of GB/T 2423 ... 18 Environmental testing for electric and electronic products - Part 2: Test methods - Test Z/ABMFh: Combined temperature (cold and heat)/low air pressure/vibration (random) 1 Scope This Part of GB/T 2423 specifies the basic requirements, severities, test procedures and other technical details for the combined temperature (cold and heat)/low air pressure/vibration (random) test. This Part applies to the determination of the adaptability of products under the combined effects of temperature (cold and heat), low air pressure and vibration (random). This Part applies as a reference to combined tests with temperature changes. 2 Normative references The provisions in following documents become the provisions of this Part of GB/T 2423 through reference in this Part. For dated references, the subsequent amendments (excluding corrigendum) or revisions do not apply to this Part, however, parties who reach an agreement based on this Part are encouraged to study if the latest versions of these documents are applicable. For undated references, the latest edition of the referenced document applies. GB/T 2422, Environmental testing - Guide to drafting of test methods - Terms and definitions GB/T 2423.1, Environmental testing - Part 2: Test methods - Tests A: Cold (GB/T 2423.1-2008, IEC 60068-2-1:2007, IDT) GB/T 2423.2, Environmental testing - Part 2: Test methods - Tests B: Dry heat (GB/T 2423.2-2008, IEC 60068-2-2:2007, IDT) GB/T 2423.21, Environmental testing - Part 2: Test methods - Test M: Low air pressure (GB/T 2423.21-2008, IEC 60068-2-13:1983, IDT) GB/T 2423.26, Environmental testing - Part 2: Tests methods - Test Z/BM: Combined dry heat/low air pressure tests (GB/T 2423.26-2008, IEC 60068-2- 41:1976, IDT) GB/T 2423.43, Environmental testing for electric and electronic products - Part 2: Test methods - Mounting of specimens for vibration impact and similar dynamic tests (GB/T 2423.43-2008, IEC 60068-2-47:2005, IDT) GB/T 2423.56, Environmental testing - Part 2: Test methods - Test Fh: Vibration, broadband random and guidance (GB/T 2423.56-2006, IEC 60068-2-64:1993, IDT) GB/T 2424.1, Environmental testing for electric and electronic products - Guidance for high temperature and low temperature tests (GB/T 2424.1-2005, IEC 60068-3- 1:1974, IDT) GB/T 4796, Classification of environmental conditions - Environmental parameters and their severities (GB/T 4796-2008, IEC 60721-1:2002, IDT) 3 Terms and definitions For the purposes of this Part, the terms and definitions given in GB/T 2422, GB/T 2423.1, GB/T 2423.2, GB/T 2423.56, GB/T 2423.21 and GB/T 2423.26 apply. 4 General description This test is a combined test of Test A (cold), Test B (dry heat), Test M (low air pressure) and Test Fh (vibration (random)). The test specimens shall be subject to a vibration (random) test, a temperature test and a combined temperature/low air pressure test at the test room temperature in sequence according to the test procedure, and finally superimposed with vibration (random) to make the test specimens withstand a combined test of temperature (cold and heat)/low air pressure/vibration (random). When the test specimen has passed a single vibration (random) test, a single temperature test and a combined temperature/low air pressure test, the combined temperature (cold and heat)/low air pressure/vibration (random) test can be directly carried out. Whether the test specimen is in working condition during the test shall be stipulated by the relevant specifications. 5 Test equipment 5.1 General requirements for test equipment Unless otherwise specified in the relevant specifications, the test equipment shall meet the requirements for test equipment in GB/T 2423.1, GB/T 2423.2, GB/T 2423.21 and GB/T 2423.56. It is at the test room temperature in the comprehensive test chamber (room). The test specimen shall be installed on the vibrating table according to the specified axial direction under the state of no packaging and no power supply, and then the vibration (random) test shall be carried out according to the severity specified in the relevant specifications. When required by relevant specifications, the test specimens shall be tested for performance. 10.2.2 Temperature test Keep the test specimen in the installation during the vibration (random) test. The temperature in the test chamber (room) shall be adjusted to the value specified in the relevant specifications, and the temperature of the test specimen shall be stabilized. The average rate of temperature change in the test chamber (room) is: 0.7 °C/min ~ 1 °C/min (the average rate is calculated every 5 minutes). When required by the relevant specifications, perform performance testing on test specimens. 10.2.3 Combined temperature/low air pressure test After 10.2.2, the air pressure in the test chamber (room) drops to the value specified in the relevant specifications; the rate of air pressure change shall not be greater than 10 KPa/min or as specified in the relevant specifications. After the temperature and air pressure reach the specified value of the relevant specification and stabilize, when required by the relevant specifications, carry out a performance test on the test specimen. 10.2.4 Combined temperature (cold and heat)/low air pressure/vibration (random) test After the temperature and air pressure reach the specified value and stabilize, carry out the vibration (random) test according to the severity stipulated in the relevant specifications. When the vibration response check is required to determine the critical frequency of the test specimen, the temperature and air pressure shall be kept constant for the specified duration. See Figure 2 or Figure 3. When required by the relevant specifications, perform performance testing on test specimens. Stop the vibration at the end of the test, and cut off the power or unload the test specimens running (or working) during the test. 11 Intermediate inspection Intermediate inspection shall be completed within the shortest possible time before the end of the test. Relevant specifications may specify loading and/or testing during or at the end of the test (the test specimen shall be still in the test chamber), and the testing items and time shall be specified when necessary. When testing, the test specimen shall not be taken out of the test chamber (room). Note 1: During the test period, the test specimen shall not be taken out of the test chamber (room) for detection before recovery, and then put back into the test chamber (room). Note 2: If it is necessary to know the performance of the test specimen at a specific time before the end of the duration, an additional batch of test specimens shall be added for each specific time. 12 Recovery The air pressure in the test chamber (room) shall return to normal atmospheric pressure at a rate not greater than 10 KPa/min. During pressurization, temperature control is not necessary. After the air pressure is recovered, the temperature in the test chamber (room) shall return to the normal laboratory climate state at a rate not greater than 1 °C/min (the average rate is calculated every 5 minutes). Thereafter, the test specimens shall be recovered in the test chamber (room) according to the relevant specifications. See Figures 2 and 3. Test specimens shall be recovered under standard atmospheric conditions. When the standard atmospheric conditions are not suitable for the test specimens, other recovery conditions may be stipulated in the relevant specifications. When the test specimen is recovered under standard atmospheric conditions, the recovery time shall be sufficient to allow it to reach temperature stabilization, with a minimum time of 1 h. When several test specimens are tested at the same time, and the recovery time of 1 h is not enough, the maximum recovery time shall be 2 h, within which the test must be completed. If required by the relevant specifications, energize or load the test specimen during the recovery period, and test its performance continuously. Note: For test specimens with a low temperature, in order to remove water droplets, the test specimens can be shaken manually, or blown with air at room temperature for a short time. Annex A (informative) Guidelines A.1 General instructions A.1.1 Other applicable standards The test method of combined temperature (cold and heat)/low air pressure/vibration (random) is formulated on the basis of GB/T 2423.1 or GB/T 2423.2, as well as GB/T 2423.56 and GB/T 2423.21. Therefore, the relevant basic test principles in GB/T 2424.1 are also applicable to this combined test. A.1.2 Test air pressure range This combined test considers the air pressure range commonly used on the ground and aircraft; the air pressure lower than 1 KPa is not within the range of this Part. A.1.3 Selection of cooling method In the air pressure range considered, the surface temperature of the heat dissipation test specimen will be greatly reduced under the condition of forced air circulation compared with the “free air” condition, so the “free air” condition shall be adopted for the heat dissipation test specimen. However, considering the additional thermal interference generated by the vibrating table and the fact that the equipment cannot meet the “free air” condition, the forced air circulation test method with a wind speed of less than 0.5 m/s is allowed at this time. A.1.4 Determination of specimen quantity Under low air pressure conditions, due to the decrease in the efficiency of convective heat transfer and the increased influence of heat radiation, the mutual heat interaction between the heat dissipation test specimens in the same test chamber (room) also increases. Due to thermal interference caused by radiation, it is best to test only one test specimen at a time in this test. For non-heat dissipation test specimens and those heat dissipation test specimens known to have little thermal interference with each other (which does not affect the reproducibility of the test), multiple test specimens are allowed to be tested together. A.1.5 Natural frequency of test specimens Since the change of material properties caused by temperature will cause the natural frequency of the test specimen (such as rubber or plastic device) to drift (that is, drift to the direction of high frequency at low temperature, and drift to the direction of low frequency at high temperature), it is necessary to obtain the natural frequency of test specimens precisely. The vibration response check shall be carried out under combined environmental test conditions. A.1.6 Combined test procedure For the combined test procedure of the test specimens, conduct a combined random vibration and temperature test first, and then a combined temperature (cold and heat)/low air pressure/vibration (random) test. A.1.7 Recovery During the pressure recovery period, no temperature control is necessary. After the air pressure is recovered, the temperature in the test chamber (room) shall return to the normal laboratory climate state at a rate not greater than 1 °C/min (the average rate is calculated every 5 minutes). A.2 Environmental effects of the combined temperature (cold and heat)/low air pressure/vibration (random) test The simultaneous action of temperature, low air pressure and vibration on the test specimen may produce the following combined effects: a) changes in material properties caused by temperature will increase the deformation and cracking of sealing equipment or seals at low air pressure, which is aggravated by the superposition of vibration stress and increases the possibility of leakage; b) under the simultaneous action of low air pressure and temperature, the plastic decomposition products in engineering plastics are volatilized, resulting in changes in the mechanical or electrical properties of the parts. When superimposed with vibration stress, the tendency of deformation and cracking of parts is increased; c) other combined effects not revealed by individual or combined tests. A.3 Measurement of environmental parameters A.3.1 Temperature measurement Under the combined environmental conditions of low air pressure and vibration, the temperature sensor with small mass shall be selected for temperature measurement, and shall be installed firmly so that it will not change the dynamic characteristics of the monitoring point. For heat dissipation test specimens, radiation shielding shall be used around the temperature sensor to reduce errors caused by thermal radiation of test specimens. A.3.2 Air pressure measurement ......
 
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.