Test Methods, Standards

The most extensive body of tests are provided under the auspices of ASTM Standard methods. Specific ASTM test designations and descriptions are available (48). The other compendium of fire-retardant tests are contained ia Federal Test Method Standards 191A (49). 

Federal Test Method Standards 191 A, General Services Administration, Washington, D.C., July 20,1978. 

Properties, Specifications, and Test Methods Standard test methods are required to measure the properties of electroplated materials. Documents on plating specifications for many phases of the plating process are pubHshed by such organizations as the Federal government, the military, ASTM, ISO, SAE, etc. An excellent cross-index of these is available (37). 

An alternate test for charge-dissipating performance is the charge decay test, in which the time of charge decay is measured after a potential of 5 kV has been applied to the specimen (Federal Test Method Standard 101C, Method 4046.1). For many purposes, a... 

The number and type of test pieces exposed for each measurement point will depend on the property being measured. If measurement is non-destructive, e.g., loss of mass or colour, then the same specimens can be used throughout the test, being replaced in the oven after each measurement. If the measurement is destructive then one set of specimens must be prepared for each combination of duration and temperature. It is recommended to expose at least two reserve sets in case the threshold level has not been reached by the end of the last planned duration. Usually the number specified in the relevant test method standard is chosen but, again, the more the better. An example and some of the problems are described in Section 12.2. 

INTERNATIONAL ORGANIZATION FOR STANDARDIZATION, Precision of Test Methods - Standard 5725, Geneva, ISO, 1981 (revised 1986 with further revision in preparation). 

Grade JP-3 NATO symbol none Grade JP-4 NATO symbol F-40 Grade JP-5 NATO symbol F-42 Federal test method standard No. 791 ASTM standards... 

The mercaptan-sulfur determination may be waived at the option of the Inspector, if the fuel is considered Doctor sweet when tested in accordance with Method 5203 of Federal Test Method Standard No 791... 

Inspection. Unless otherwise specified by the procuring activity, inspection shall be in accordance with Federal Test Method Standard No 791, Method 9601... 

Thermal stability. A manual, semiautomatic or automatic CFR fuel coker shall be used. The equipment and operating procedures shall be in strict accordance with Method 3464 of Federal Test Method Standard No 791. No deviation from this method is aUowed... 

Dissolve 5.00g of the specimen in 76g of toluene and 19g of ethanol conforming to Spec O—E—760. Determine the viscosity at 25° according to Method 305 of Federal Test Method Standard No 791, except that the results in cent stokes should be converted to centipoises as follows ... 

Water Content, as Received — 0.20%, maximum. Determine its content in accordance with Method No 3001 of Federal Test Method Standard No 7 1... 

Use Method 1001 of Federal Test Method Standard No 791, except that, due to the high viscosity of the material, cooling water at 40—45° shall be substituted for the ice-water in the condenser... 

Distillation. Distillation shall be conducted according to Federal Test Method Standard No 141 Test Method No 4301.1, except that distillation shall be conducted at a pressure of 760 mm of mercury or corrected thereto by adding 0.043° C for each mm under 760 mm or subtracting for every mm over 760 mm... 

Flash point. The flash point of the material shall be determined according to Federal Test Method Standard No 791 Test Method No 1103.6 (ASTM D92-66), except that the fire point need not be determined 4-3.9 Odor. Odor shall be determined by pour-... 

The method intended to measure the "fineness of grind is described as Method 4411.1 (Sept 1, 1965) of Federal Test Method Standard No 141a. The apparatus consists of a device known as the Hegman Gage... 

Textile Test Methods, Federal Test Methods Standard No. 191, Dec. 14, 1968. 

ASTM D4483, 2003. Standard practice for evaluating precision for test method standards in the rubber and carbon black industries. 

In ISO TC 45, Rubber and Rubber Products, a decision was made recently to structure test method standards into a number of parts so that the requirements for different purposes are more clearly separated. The idea was that the first part for a given property group would be a guide and subsequent parts would be specific test methods, but it remains to be seen how this develops in practice. A guide in ISO is distinguished by giving advice as to how to test without being mandatory. 

As it was recognized that the number of variations included in many test method standards was not helpful in respect of obtaining input for databases, there was an initiative in the plastics industry that produced international standards for acquisition and presentation of single and multipoint data. These specify the particular test methods and test conditions to produce strictly comparable data. Very recently, this approach has been taken up in ISO TC 45 and drafts circulated based on British standards4, 5. These standards are not explicit about including thermoplastic elastomers and, as discussed in Chapter 2, Section 9, an acquisition standard for these materials has been proposed in ISO TC 61, Plastics. An example of the problems resulting from lack of consensus on test methods was evident for EPDM polymers and the results of collaboration to rectify this have been published6. 

Whilst thermoplastic elastomers are being included in most test method standards, we do not have a procedure for their preparation and moulding. 

To stamp, for example, a dumb-bell from sheet requires only a die and a press, although a hammer has been known to replace the latter. There has been a tendency to treat stamping as so simple an operation as to merit little attention, despite the fact that the accuracy of the final test result depends very considerably on the accuracy with which the test piece was prepared. The necessary dimensions of the die are given in the relevant test method standard, for example ISO 375 for tensile properties, but there is ISO 235292 which deals specifically with the preparation of test pieces for physical tests. ISO 23529 now incorporates what was ISO 4661 Part 1 but ISO 4661 Part 2 still exists and deals with the preparation of samples for chemical tests. The British standard is identical to the ISO standard7. 

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. 

Almost all test methods require the test piece dimensions to be measured and it was the usual practice for each test method standard to specify the apparatus and means of making the measurements. Over the years, the procedures became standardised such that it was reasonable to produce a separate standard dealing specifically with dimensions, to which all the test method standards could refer. 

No attempt will be made in this section to consider all the separate measurement clauses to be found in current test method standards. Until the ISO standard for the measurement of dimensions has become established long enough for all test methods to have been revised and reference it (if that happens), each test method will have its own procedure and there will not be universal agreement on detail. The essentials are to distinguish between a non-contact measurement and one applying a specified pressure, in the latter case to use the correct standard pressure, and to measure within the accuracy limits specified. 

Standard rubbers are given in several of the test method standards. Some are purely for normalizing the abrasive and have no particular service relevance. Others, such as those based on a tyre tread compound or a shoe sole type material, have the advantage of a practical significance as well as a normalizing role. There is no reason at all why, for a particular investigation, an in-house standard representative of the type of material being evaluated should not be used. 

For many years, the only abrasion test method standardized internationally was the apparatus commonly known as the DIN abrader... 

There are no ISO, ASTM or British fire test method standards specifically for solid mbbers and there is no active fire test work being pursued in TC 45. There are, however, a number of published international test methods for cellular materials and plastics, the majority of which could be applied to rubbers. A comprehensive account of fire testing of plastics has been given by Paul in the Handbook of Polymer Testing81. There may be fire resistance requirements for particular rubber products and some examples were given by Schultz110. 

A text devoted to the physical testing of rubbers based on experience at Rapra first appeared in 1965 with the publication of the work of the late Dr J R Scott, who was widely regarded as the father of rubber testing . The first edition of my own book came in 1979 and the second, third and now this fourth edition reflect the continuing technical developments over four decades. There have been many changes in the methods used but, more especially, there have been vast improvements to much of the instrumentation as more modern technologies are adopted by instrument manufacturers and the requirements of industry become more sophisticated. Since the last edition of the book, the majority of International (ISO) and ASTM test methods standards have been revised. 

Test method standardization (TMS) calls for several actions that involve 1) preparation of a formal draft test method document for each bioassay intended for standardization, 2) a critical review by an expert subcommittee, 3) the preparation of a final draft test method, 4) an international peer review of each test method, 5) an inter-calibration exercise of the final draft test method, 6) finalization of each test method and 7) the formal publication of the toxicity test method document. Environment Canada (EC) has been particularly active in biological test method standardization and has thus far contributed 18 standardized aquatic and sediment... 

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