Electronics environmental tests

Most design books continually report that plastics cannot take the heat of metal (steel, etc.) indicating that plastics cannot take heat. As reviewed, by far practically most plastic products do not have to take any more heat then the human body. Practically all plastics easily meet this heat requirement for these type products and in fact many types of these plastics meet the higher heat requirements of plastic products that exist under the engine hood of an automobile, in the trunk of an automobile (excellent user-environmental test), electrical/electronic devices, etc. 

The results of studies are discussed into the co-combustion of plastics with respect to the recycling of scrap plastics from the building, packaging, automotive, electrical and electronic industries. Tests were carried out by APME on plastic waste from these end-use industries in a typical large scale EfW facility with respect to operational and environmental problems. 

Apart from qualification testing, a medical device should undergo a number of environmental tests, as oudined in standards such as BS 2011 (British Standard for environmental testing), CISPR 11 (limits and methods of measurement of electro-magnetic disturbance characteristics of industrial, scientific), ISM (medical radio frequency equipment), and BS4826 (British Standard for packaging electronic equipment for transport). 

Second, the uncertainty in measurement of relative humidity using commonly available electronic hygrometers is at least 2% of the reading and is often greater due to non-linearity, hysteresis and drift [see Pragnell, R.F. SIRA Ltd "The relationship between humidity calibration standards and standards for environmental testing," Humidity seminar, June 1988]. 

JIS C 0052-95. Environmental testing procedtrre of electronic and electrical resistance to solvents. 

Zhang Shifeng and Li Rong. Bayesian reliability analysis based on Dirichlet priors [J]. Electronic Product Reliability and Environmental Testing, 1996,6 12 15. 

Environmental Testing of Electronic and Associ- MIL-T-5422 ated Equipment... 

TABLE 6— Environmental tests and standards for electronics corrosion. 

Environmental tests for electronics can be divided into two groups based on the information they provide. 

China Electronic Product Reliability and Environmental Testing Research Institute, Guangzhou, China... 

Khan, M. M. (1989). Environmental testing for commercial and mUitaiy applications. Electronic materials handbook, vol. 1, packaging (pp. 493—503). ASM International, Materials Park, OH. 

For the failure analysis of the test samples after the harsh environmental tests, various analysis tools are employed, e.g., scanning electron microscopy (SEM) with a cross-sectional analyzing technique, x-ray microscopy, A-, B-, and C-mode scanning acoustic microscopy (A-SAM, B-SAM, and C-SAM, respectively), and tomographic acoustic microimaging (TAMI), to analyze the failure samples. The continuous measurement of the electrical resistance should consequently be conducted during all of the environmental tests mentioned above. 

ASTMD 1169-11. Standard test method for specific resistance (resistivity) of electrical insulating liquids. JIS C 0052-95. Environmental testing procedure of electronic and electrical resistance to solvents. 

Khan MM. Environmental testing for commercial and military applications. In Electronic Materials Handbook. Vol 1. Packaging. Materials Park, OH ASM International 1989 493—503. 

The production of reduced products like methane and ammonia by the gut microbial flora has important environmental consequences, as such compounds contribute to the chemical and biological oxygen demand. The detection of dissolved oxygen in the gut of piglets led to tests to show whether methane and other reduced products could be oxidized in the pig gut. The production of C-labelledCOj from C-labelledmethane has been demonstrated however, it is calculated that at most only a very small proportion of methane produced is likely to be oxidized using O 2 as electron acceptor. Methane may also be oxidized anaerobically, but only an extremely small amount of methane is likely to... 

Modem electronic replacements for the Orsat apparatus include equipment manufactured in the United States by Bacharach, Inc. (www.bacharach-inc.com). This company produces handheld and boxed instruments that can be employed as comprehensive combustion and environmental analyzers, gas burner combustion testers, single gas analyzers, draft gauges, smoke test sets, sling psychrometers, and the like. 

By a strict definition, these electrical and electronic wastes are hazardous. Fluorescent lamps contain mercury, and almost all fluorescents fail the U.S. Environmental Protection Agency (U.S. EPA) toxicity test for hazardous wastes. Fluorescent lamp ballasts manufactured in the mid-1980s contain polychorinated biphenyls (PCBs), a carcinogen most of these ballasts are still in service. Batteries can contain any of a number of hazardous materials, including cadmium (nickel-cadmium... 

The two metal surfaces covered by SAMs are brought into contact by the use of a micro-manipulator in the presence of a liquid medium, such as hexadecane the presence of hexadecane transforms the defects of the SAMs into insulating sites. The use of a semitransparent solid surface (Au or Ag) allows (1) evaluation of the contact area by collecting the image of the contact area by a mirror and (2) electrical measurements under irradiation of the SAMs through the Au surface. The disadvantage of Hg-based junctions is related to the environmental unfriendly characteristics of Hg, which prevent any application. For this main reason, these junctions are valuable only as versatile test-beds for organic electronics. 

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