Metals test procedures

Table S Comparison of Various Laboratory Metals Testing Procedures [38] ... 

IClueh, R. L. and DeVan, J. H., "Liquid Metal Test Procedures, Handbook on Corrosion Testing and Evaluation, W. H. Ailor, Ed., John Wiley Sons, NY, 1971. 

AWS) has issued specifications covering the various filler-metal systems and processes (2), eg, AWS A5.28 which appHes to low alloy steel filler metals for gas-shielded arc welding. A typical specification covers classification of relevant filler metals, chemical composition, mechanical properties, testing procedures, and matters related to manufacture, eg, packaging, identification, and dimensional tolerances. New specifications are issued occasionally, in addition to ca 30 estabUshed specifications. Filler-metal specifications are also issued by the ASME and the Department of Defense (DOD). These specifications are usually similar to the AWS specification, but should be specifically consulted where they apply. 

Multiple Metals Testing The samphng method commonly used to measure emissions of metals from stationaiy sources is contained in 40 CFR 266, Appendix IX. The procedure is titled Methodology for the Determination of Metals Emissions in Exhaust Gases from Hazardous Waste Incineration and Similar Combustion Processes. It is also currently pubhshed as Draft EPA Method 29 for inclusion in 40 CFR 60. 

Water used in any testing procedure should be free of corrodents and of substances whose decomposition products may be corrosive. Metal surfaces should be dried after testing and kept dry prior to service. 

A British Standards draft for development has been developed which defines a test procedure to determine the potential of metals to contaminate drinking water in contravention of the requirements of the EC Directive. Although primarily meant for new materials, traditional plumbing alloys will also have to be shown to be satisfactory. 

Soil resistivity The role of soil in the electrical circuitry of corrosion is now apparent. Thus the conductivity of the soil represents an important parameter. Soil resistivity has probably been more widely used than any other test procedure. Opinions of experts vary somewhat as to the actual values in terms of ohm centimetres which relate to metal-loss rates. The extended study of the US Bureau of Standards presents a mass of data with soil-resistivity values given. A weakness of the resistivity procedure is that it neither indicates variations in aeration and pH of the soil, nor microbial activity in terms of coating deterioration or corrosion under anaerobic conditions. Furthermore, as shown by Costanzo rainfall fluctuations markedly affect readings. Despite its short comings, however, this procedure represents a valuable survey method. Scott points out the value of multiple data and the statistical nature of the resistivity readings as related to corrosion rates (see also Chapter 10). 

Testing procedures for liquid-metal corrosion are given in Chapter 19. 

The Huey test is widely used in the USA whilst the H2SO4-CUSO4 test is preferred in the UK, with an increasing tendency to use the metallic copper variant. The H2SO4-CUSO4-CU test procedure is given in BS 5903 1980 (1987). 

Examples of various vibratory test procedures for studying cavitation-erosion of metals in inhibited engine coolants have been given in an ASTM Special Technical Publication... 

Corrosion of metals and alloys stress corrosion testing. Part 1 General guidance on testing procedures... 

Testing of metals for resistance to sulphide stress cracking at ambient temperatures Accelerated test procedures for screening atmospheric surface coating systems for offshore platforms and equipment... 

The tube can be a source of metal particles and must be cleaned carefully before sterilization. The USP contains a test procedure and limits the level of metal particles in ophthalmic ointments. The total number of metal particles detected under 30 x magnification that are 50 pm or larger in any dimension is counted. The requirements are met if the total number of such particles counted in 10 tubes is not more than 50 and if not more than one tube is found to contain more than 8 such particles. 

Most microalgal toxicity tests procedures recommend the use of initial cellular concentrations of 104 cells mL 1. This cellular concentration should be selected because it is the minimum cellular concentration that can be measured in haematocytometers (Neubauer chambers). Furthermore, natural cellular concentrations in non-polluted conditions (in marine environments) are often below the concentration mentioned. The importance of cellular density at the beginning of the test has been demonstrated for certain toxicants [43]. The lower the cellular concentration, the higher the sensitivity of the test, at least for certain types of xenobiotics, such as heavy metals. 

Ozone decay was measured in an office, a home, and several metal test facilities. Measurements were carried out with a Mast ozone meter and an MEC chemiluminescence ozone detector. The latter was calibrated with a stable ozone source and the epa neutral buffered potasaum iodide procedure. (It was noted over a wide range of concentrations that the mec meter measurements were consistently higher than those of the Mast meter by a factor of 1.3. That this is essentially identical with the findings of the DeMore committee is interesting.) Ozone generated by a positive corona ionizer was introduced into the test facilities. Ozone decay in a metal-walled room was found to be first-order, with the rate constant... 

In JP monographs, the specification value and testing procedure are described as a comparative limit test for the quantity of heavy metals that exist in drug substances as inorganic impurities. The permissible limit on the ppm scale for heavy metals (as Pb) is prescribed as the specification value. From the development stage to the establishment of the limit test method for a monograph, the validation in place has to be done for both the quantitative method for actual measurement and the comparative limit method with the control solution. However, the quantitative procedure has not been stated in the section on the heavy metals limit test in the JP s General Tests and other Japanese official... 

Metal speciation procedures, which have been verified under controlled laboratory conditions and evaluated by means of bioassays, will require further verification in order to determine their ecological effects. For example, how does the response of the bioassay test species to a toxic metal fraction relate to the toxicity to larger organisms such as fish in the natural environment Bioaccumulation of metals in populations has been very difficult to relate to metal speciation measurements. There is a challenge for analytical chemists to develop metal speciation procedures that are relevant to ecotoxicology (Morrison and Wei, 1991). 

The WTD is a cumulative rating based on observation of deposits in the groove and land areas of the piston and lacquer on piston skirts which have been weighted and calculated in accordance with the test procedure. The evalated lubricating oils also contained, where required, conventional viscosity improver, a metal detergent and ZDDP in mineral base oil. The WTD ratings were as follows ... 

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