Some Testing Methods

When both temperature and humidity are controlled, the standard conditioning time is a minimum of 16h, and where temperature only controlled at 23°C or 27°C, a minimum of 3h. At the sub-normal and elevated temperatures it is simply specified that the time should be sufficient for the test piece to reach equilibrium with the environment. Tables of approximate times required to reach equilibrium in both air and liquid media have been given6 for a wide range of temperatures and various test piece geometries, and a relevant selection of these is reproduced in an annex to the standard. Also, specific instructions are given in some test method standards. 

In some test methods it is recommended that the color of the ash be noted, as it gives an approximate indication of the fusion point. Generally, highly colored ash has a low fusion point, whereas white ash, provided that there are essentially no basic oxides, has a high fusion point. 

A clear area where there is a need for testing is that of the composite components, namely, the starting fibers, the matrix material, and the fiber-matrix interface. Some test methods for determining the interface properties are discussed in the previous section, others will be described later in this section. For determining the properties of matrix materials, recourse can be had to a large number of techniques developed over several decades. Several comprehensive reviews of these techniques have been published in the past 10-15 years,54,55 and the topic will not be discussed further here. 

An annual schedule of validation of methods for each type of test could be established as regards limited-scope accreditation. Some test methods similar among themselves may allow the use of previously established validation procedures, such... 

In order to compare the relative sensitivity of the MARA test with some test methods employed for regulatory purposes range of EC50 values for three pertinent tests are given in Table 3.1.2. 

In addition to the specific comments, the panelists discussed the availability and implications of medical tests to characterize PCB levels in blood, body fat, and breast milk. Though the profile clearly states that routine clinical tests are not available, some panelists suggested that ATSDR include more detailed information on this topic, such as whether tests will be commercially available, how people can get tested by physicians and specialists, and how medical professionals should interpret the significance of measured PCB levels. During this discussion, several panelists indicated that the profile does not acknowledge that no treatments are currently available to reduce body burdens of PCBs. One panelist noted that PCB tests are currently available to physicians, but some testing methods have relatively high detection limits and inadequate quality assurance measures. 

The determination of density (specific gravity) (ASTM D-287, ASTM D-891, ASTM D-941,ASTM D-1217, ASTM D-1298,ASTM D-1555, ASTM D-1657, ASTM D-2935, ASTM D-4052, ASTM D-5002, IP 160, IP 235, IP 365) provides a check on the uniformity of the gasoline, and it permits calculation of the weight per gallon. The temperature at which the determination is carried out and for which the calculations are to be made should also be known (ASTM D-1086). However, the methods are subject to vapor pressure constraints and are used with appropriate precautions to prevent vapor loss during sample handling and density measurement. In addition, some test methods should not be appUed if the samples are so dark in color that the absence of air bubbles in the sample cell cannot be established with certainty. The presence of such bubbles can have serious consequences for the reUabiUty of the test data. 

Eiirther laboratory and greenhouse test methods development is needed to assess the potential adverse effects of genetically altered microbial pesticides. Although some test methods are available atri analysis of field testing proposals can proceed on a case-by-case basis, there is a need for further research in test method development. 

Migration studies are affected by several parameters including simulant, temperature, the size (and especially the thickness) of the sample, and the ratio of sample volume to simulant volume. The proper selection of simulants is especially important to ensure that the test yields useful data. " " The following section describes some test methods of study and provides experimental data on migration. 

Under the normal conditions of a real fire, combustion is never complete. The carbon content of the materials is partially transformed into carbon dioxide a good deal is oxidized only to carbon monoxide or remains as char residue. For this reason, some test methods aim at modelling natural circumstances. The results of these methods should refer to particular experimental conditions in order to be as informative as possible for practical purposes, but they should not be regarded as true heats of combustion. 

Standard test methods have been developed for examining the ignition behavior of polymeric materials. Some test methods provide qualitative data, while others provide partial or complete quantitative data for the ignition resistance of materials (Sectimi 53.3, Tables 53.3 and 53.4). The following are examples of the common standard test methods used for examining the ignition resistance of materials ... 

Selected ASTM and similar ISO standards are shown in Table 3.2. Some test methods and specifications shown are prior to or after the year 2000. 

Test order is usually such that the continuity test is performed first. This verifies that each network is intact within itself, and that contact is established between any test fixture and the product. The isolation test can then be performed using only a single test point per network. Some test methods attempt indirect inference of continuity and isolation without making direct current (DC) measurements. These methods are commonly employed in flying probe systems. 

As some test methods use flammable gases such as propane in the flame photometers and ethylene, die safe handling of these gases is viul. 

A number of nondestructive test (NDT) techniques have been developed that permit detection and measiu-ement of both internal and surface flaws. Such techniques are used to examine stmctmal components that are in service for defects and flaws that could lead to premature faUme in addition, NDTs are used as a means of quahty control for manufacturing processes. As the name implies, these techniques do not destroy the material/structure being examined. Furthermore, some testing methods must be conducted in a laboratory setting others may be adapted for use in the field. Several commonly employed NDT techniques and their characteristics are listed in Table 8.2. One important example of the use of NDT is for the detection of cracks and leaks in the walls of oil pipelines in remote areas such as Alaska. Ultrasonic analysis is utilized in conjunction with a robotic analyzer that can travel relatively long distances within a pipeline. 

Besides complexity, analysis of viscous oils may be complicated by handling problems. The higher viscosity of the fluids makes them more difficult to sample and transfer. Many viscous oils have a very dark color, which causes problems with some test methods. 

Note S—For some Test Method D 323 apparatus, a Number 6.3 rubber stopper has been found satisfactory. For the horizontal or Herzog apparatus, a Number 3 rubber stopper and a Number 000 cork in the vent hole is satisfactory. Another procedure is to attach a spare liquid chamber to the vapor chamber during the conditioning period. A third alternative is to utilize a cap threaded to match the threads of the vapor chamber. Several apparatus manufacturers have indicated the intention to supply such caps for equipment. In any procedure used, the interior surfaces of the vapor pressure apparatus and the sample must be kept completely free of water. 

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