Equivalent Test Method

Machine and stmctures subjected to cyclic loadings quite often if not always present complex geometric shapes that favor the presence of localized plastic deformations. 

6 Stiain-Based Fatigue Analysis Low Cycle Fatigtie 

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Pour point The pour point measures the temperature at which a base stock no longer flows, and for paraffinic base stocks, pour points are usually between -12°C and -15°C, and are determined by operation of the dewaxing unit For specialty purposes, pour points can be much lower. The pour points of naphthenic base stocks, which can have very low wax content, may be much lower (-30°C to -50°C). For very viscous base stocks such as Bright stocks, pour points may actually reflect a viscosity limit Pour points are measured traditionally by ASTM D97,4 but three new automated equivalent test methods are the tilt method (ASTM D5950), the pulse method (ASTM D5949), and the rotational method (ASTM D5985). 

It is a liquid, other than an aqueous solution containing less than 24 percent alcohol by volume and has flash point less than 60°C (140°F), as determined by a Pensky-Martens Closed Cup Tester, using the test method specified in ASTM Standard D-93-79 or D-93-80 or a Setaflash Closed Cup Tester, using the test method specified in ASTM Standard D-3278-78, or as determined by an equivalent test method approved by the Administrator. ... 

It is an ignitable compressed gas as defined by DOT, as determined by the test methods provided by that agency or equivalent test methods approved by the Administrator. 

It is aqueous and has a pH less than or equal to 2 or greater than or equal to 12.5, as determined by a pH meter using either an EPA test method or an equivalent test method approved by the Administrator. The EPA test method for pH is specified as Method 5.2 in Test Methods for the Evaluation of Solid Waste, Physical/Chemical Methods. "... 

It is a liquid and corrodes steel (SAE 1020) at a rate greater than 6.35 mm (0.250 inch) per year at a test temperature of 55°C (130 F) as determined by the test method specified in NACE (National Association of Corrosion Engineers) Standard TM-01-69 or an equivalent test method approved by the Administrator. 

Several of these ASTM test methods have also been separately issued by other international standards writing bodies such as IP, ISO, DIN, JIS, and AI OR. These equivalent test methods are listed in Table 5 [9]. In an ever-expanding global market, it is useful in commerce to recognize the analytical methodology used in other industrialized nations. 

Note "Gases which cause or contribute to the combustion of other material more than air does means pure gases or gas mixtures with an oxidizing power greater than 23.5% (as determined by a method specified in ISO 10156 or 10156-2 (incorporated by reference. See 1910.6) or an equivalent testing method.)... 

Analytical and Test Methods. Potentiometric titration with sodium hydroxide [1310-73-2] is employed. Both equivalent points are... 

Fig. 1. Relative efficiency of plasticizers where H represents Cg phthalate +, C q phthalate A, phthalate and , phthalate phr = parts per hundred mbber. Values for the trimeUitates fall in the shaded area. BSS 35 is equivalent to a Shore A hardness of 80, test method BS2782.

Method vahdation is the demonstration, accompanied by a high degree of assurance, that the test method consistently performs as expected. Vahdation of test methods is especially important when the intended method differs from a compendial or other referenced method and yet is expected to provide equivalent or perhaps better test results. When the reference method is to be used unchanged, no vahdation is necessary. Thus a primary benefit of using compendial methods as written is not needing to do a method vahdation. 

Method Transfer. Method transfer involves the implementation of a method developed at another laboratory. Typically the method is prepared in an analytical R D department and then transferred to quahty control at the plant. Method transfer demonstrates that the test method, as mn at the plant, provides results equivalent to that reported in R D. A vaUdated method containing documentation eases the transfer process by providing the recipient lab with detailed method instmctions, accuracy and precision, limits of detection, quantitation, and linearity. 

This is the most commonly misused test method, except in those few cases where one is truly only comparing two groups of data and the group sizes are roughly equivalent. Not valid for multiple comparisons (because of resulting additive errors) or where group sizes are very unequal. 

Currently there are few methods for specific investigation of immunotoxic effects, which are regarded as sufficiently validated for routine use (EC 2003). The plaque forming assay or the equivalent using the ELISA method (Enzyme-linked Immunosorbent Assay) are recommended to identify altered T-cell-dependent humoral responses. Of particular value for hazard assessment are the so-called host resistance models, in which the clinical relevance of immunotoxicity can be evaluated. Other methods may also be of value to provide information on the mode of immunotoxic action, e.g., mitogen stimulation tests and leucocyte phenotyping. However, further work is needed on standardization and validation of these test methods. 

However, another large meta-analysis study found no difference between different viability testing methods for predicting survival after revascularization, suggesting that decisions driven by viability studies are clinically equivalent and have similar outcomes, irrespective of the technique used [88]. While improved LV function is a major factor affecting... 

A complementary approach is to conduct the assays under high-throughput automated conditions. This can be either through the miniaturization of assays, that is, 96-384 plates and if possible 1536, or through the use of alternative assay technologies (e.g., microfluidics). Both scenarios require studies of equivalency testing and backwards compatibility with previous methods and results. 

There are two different ways of carrying out this test. The first one involves taking a single sample and analysing it by both methods a number of times. The usual procedure is to undertake a number of analyses (preferably not less than 6) for the chosen sample with both methods and calculate the value of the t-statistic. This is then compared with the tabular value for the appropriate degrees of freedom at the selected confidence level. If the calculated value is less than the tabulated t value then the mean values, and hence the methods, are accounted equivalent. This method has the advantage that the number of replicates undertaken for each method does not have to be equal. However, it is not always recognised that for this test to be valid the precision of the two methods should be equal. The method used to compare the precisions of methods is the F-ratio test and is carried out as part of the procedure. 

Data can be obtained from tests in uniaxial tension, uniaxial compression, equibiaxial tension, pure shear and simple shear. Relevant test methods are described in subsequent sections. In principle, the coefficients for a model can be obtained from a single test, for example uniaxial tension. However, the coefficients are not fully independent and more than one set of values can be found to describe the tension stress strain curve. A difficulty will arise if these coefficients are applied to another mode of deformation, for example shear or compression, because the different sets of values may not be equivalent in these cases. To obtain more robust coefficients it is necessary to carry out tests using more than one geometry and to combine the data to optimize the coefficients. 

Few details of the apparatus are given in ISO 4663, it is simply stated that means shall be provided to measure frequency to 1% ( 5% in a transition region), amplitude to 1% and, for method C, the supplied energy to 2%. It is suggested that a moment of inertia of about 0.03 gm is suitable for the inertia member which may be a disc or rod. For methods B and C the torsion wire should be of such dimensions that its restoring torque is not more than 25% of the total restoring torque due to the test piece and suspension. BS 903 (equivalent to method B of ISO 4663) suggests that moments of inertia between 50 and 500 g cm are suitable and states that the tensile strain on the test piece should be between 0 and 5%. The British... 

The standard states that the measured equilibrium water vapour absorption is substantially the same as the equilibrium absorption which would be obtained by immersion in an aqueous solution and which would be in equilibrium with the vapour (apart from effects due to extraction of water soluble constituents), i.e. in a solution which would maintain the test humidity. As this implies, the equilibrium water absorption of rubber is reduced if the water is not pure and this test method, because 100% R.H. is not readily maintained, does not measure the absorption of pure water. When approaching 100% R.H. the effect is rapid and even very small amounts of a salt in solution will significantly lower the equilibrium absorption. Hence, tests intended to simulate the use of rubber in contact with an aqueous solution, rather than pure water, should be made with that solution or with one having the same equivalent relative humidity. 

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