Test standardisation

Such test guidelines often form a key part of a laboratory s formal quality assurance procedure (e.g. Good Laboratory Practice or other formal accreditation schemes) and enable test results to be audited. However, to be fully effective these quality assurance procedures need to take account of the performance characteristics of the test (quality control). Such considerations form the basis of the following section. 

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This experience is an indication that biocompatibility testing has to be adjusted for each device, and established animal models must be questioned if new classes of substances are to be tested. Standardised toxicological tests may be suitable for substances known at that time when these tests were developed. There is a need for the introduction of new types of cell culture tests as well as for better animal models and more suitable in vivo tests [49]. 

Product quality specification Contractual agreements Capacity and availability Concurrent operations Monitoring and control Testing metering Standardisation Flaring and venting Waste disposal Utilities systems... 

But laboratories using NDT methods have a set of features. Specific requirements were needed to be specified for evaluation of their technical competence. These requirements were reflected in rules of interstate standardisation - UMT 15-96 Requirements to the competence of laboratories of non-destructive testing and technical diagnostics . 

Later, US NDT TD set up the National Certification Committee of Ukraine on NDT, which had the aim of organising the personnel certification in keeping with EN 473, rendered assistance to State Standardisation Organisation of Ukraine in setting up the Technical Committee on Standardisation Technical Diagnostics and Non-Destructive Testing (TC-78), the aims of which are in tune with those of lSO/TC-135. 

For continuation of the work on standardisation in the field of NDT TD, Gosstandardt set up a Technical Committee on Standardisation Technical Diagnostics and Non-Destructive Testing (TC-78) This is a social organisation which unites the leading experts on TD NDT, and determines the priority areas of work, and qualified performers in the field of TD NDT Its main aim is unification of the standards of Ukraine with the European norms. 

A.STM. Standardisation Nem (formerly Materials Kesearch and Standards and, earlier, A.STM bulletin) American Society for Testing and Materials A monthly bulletin which covers ASTM projects, national and international activities affecting ASTM, reports of new relevant technology, and ASTM letter ballots on proposed standards. 

Handbook for Standardisation ofi Nondestructive TestingMethods, Vols. 1 and 2, MIL. HDBK-33, Dept, of Defense, Washington, D.C., 1974 R. E. Englehardt, "BibHography of Standards, Specifications and Recommended Practices," ia Nondestructive Testing Information Mnalysis Center Handbook, Nondestmetive Testing Information Analysis Center, Texas Research Institute, Austin, Tex., Mar. 1979, p. 212. 

In recent years test methods have been largely standardised by the International... 

While the pitting potential of a steel is not an absolute value, provided that test conditions are strictly standardised, it can be used to compare relative resistances to pitting corrosion initiation of steels and to determine the effects... 

Tests for quality of sealing of anodic coatings have become internationally standardised. They include dye spot tests with prior acid treatment of the surface (ISO 2143 1981 and BS 6161 Part 5 1982), measurement of admittance or impedance (ISO 2931 1983 and BS 6161 Part 6 1984), or measurement of weight loss after acid immersion (ISO 3210 1983 and BS 6161 Part 3 1984, and ISO 2932 1981 and BS 6161 Part 4 1981). Of these the chromic-phosphoric acid immersion test (ISO 3210) has become the generally accepted reference test. 

Overall figure for tests under standardised conditions for each grade of enamel. 

An apparatus for testing enamel with acid and alkaline liquids (and their vapours) was later proposed in an attempt to standardise corrosion ratings on an international basis. After surveying enamel properties and their relationship with resistance to liquids of different pH values, the concept of modifying the resistance by including specific elements in the glass structure has been outlined. ... 

The evaluation of heat treatments or the effectiveness of stabilisation by limiting carbon content of these stainless steels can be determined by subjecting specimens to the ASTM standardised acid copper sulphate test or boiling nitric acid test (ASTM A262 1986 see also Sections 9.5 and 1.3). 

Since the conditions of this test can be standardised fairly readily, it has also been used as a routine test in comparing different alloys of the same general kind in the course of studies of effects of composition on properties, as, for example, in the researches by Hanawalt, Nelson and Peloubet on the corrosion of magnesium... 

The most common of the spray tests is the salt-spray or salt-fog test which was developed originally by Capp in 1914 for studying the protective values of metallic coatings on steel under conditions that he hoped would simulate exposure to a sea-coast atmosphere. Since then the test has been used for a number of purposes, for many of which it is not well suited Although there is no standard size or shape of salt-spray box certain other features of the test have been standardised in ASTM B117 1990. Various... 

Field and Plant Tests Field exposure of test panels offers the benefit of a high degree of control over surface preparation and application. Moreover, through standardised exposure conditions, broader comparisons between both paint systems and locations are possible. More importantly, since replicates may be removed and laboratory tested periodically, changes in properties can be followed in considerable detail. At least four replicates should be examined for each exposure period to minimise the effects of atypical specimens. 

The exposure site is selected according to the service for which the data are to be applicable. For atmospheric service, such factors as marine and industrial contaminants, sunlight, dew and sand abrasion, must be considered. Atmospheric specimens are normally mounted at 45°, facing south. This has been shown to provide about a 2 1 acceleration of failure compared with a vertical exposure. Whether this or other standardised positions are used, the details of the exposure are an important part of the test record. 

Tests took place in a standardised test room provided with individual booths and the trials assessed in four sessions with five randomly grouped samples at each time. 

For this reason a thorough analysis of the level of error of flashpoint measurements is required. It is interesting to note that this situation has been criticised by a lot of authors quoted in the following pages and that ail of them have recommended a world-wide experimental approach. Moreover, they all suggested the need for an estimation method while waiting for a standardisation in tests. This standardisation has not happened yet and will be less likely to since there is no apparatus that is better than the rest and it would imply ignoring the manufacturers commercial interests. 

In addition to these standardised test methods set by regulation (in particular the transport regulations of dangerous substances), there are laboratory methods that can provide more details regarding substance behaviour. In particular, there is differential thermal analysis (DTA), thermal gravimetric analysis, calorimetry and thermomanometry, which will not be described here. 

An alternative to the measurement of the dimensions of the indentation by means of a microscope is the direct reading method, of which the Rockwell method is an example. The Rockwell hardness is based on indentation into the sample under the action of two consecutively applied loads - a minor load (initial) and a standardised major load (final). In order to eliminate zero error and possible surface effects due to roughness or scale, the initial or minor load is first applied and produce an initial indentation. The Rockwell hardness is based on the increment in the indentation depth produced by the major load over that produced by the minor load. Rockwell hardness scales are divided into a number of groups, each one of these corresponding to a specified penetrator and a specified value of the major load. The different combinations are designated by different subscripts used to express the Rockwell hardness number. Thus, when the test is performed with 150 kg load and a diamond cone indentor, the resulting hardness number is called the Rockwell C (Rc) hardness. If the applied load is 100 kg and the indentor used is a 1.58 mm diameter hardened steel ball, a Rockwell B (RB) hardness number is obtained. The facts that the dial has several scales and that different indentation tools can be filled, enable Rockwell machine to be used equally well for hard and soft materials and for small and thin specimens. Rockwell hardness number is dimensionless. The test is easy to carry out and rapidly accomplished. As a result it is used widely in industrial applications, particularly in quality situations. 

Standardisation of terminology, requirements and test methods including the potential efficacy under conditions of use. 

In a future European Standard for Surface disinfection not all details for achieving reproducible test results will be described. So every laboratory which intends to do the tests has to find by ist own experience how to get reproducible test results. This means you have to standardise the Standard. 

Standardisation of EPDM characterisation tests (molecular composition, stabiliser and oil content) for QC and specification purposes was reported [64,65]. Infrared spectroscopy (rather than HPLC or photometry) is recommended for the determination of the stabiliser content (hindered phenol type) of EP(D)M [65]. Determination of the oil content of oil-extended EPDM is best carried out by Soxhlet extraction using MEK as a solvent [66], A round robin test was reported that evaluated the various techniques currently used in the investigation of unknown rubber compounds (passenger tyre tread stock formulations) [67]. 

For ICP system control, daily testing of four elements (Ba, Mg, Zn and Ar) has been proposed [186]. The concentration of each element is determined from measured intensities via calibration with standards. For standardisation, use is made of reference solutions. Calibration of ICP-AES has been critically evaluated [187]. 

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