Standard IEC

Methods for measuring the resistivity of insulating materials are based on IEC 60093 [24] and insulation resistance is covered by IEC 60167 [25]. For conducting and antistatic materials the methods for rubbers, ISO 1853 [26] for resistivity and ISO 2878 [27] for resistance, could be adapted and there is a draft IEC standard. The general method for electric strength is IEC 60243 [28] and methods for power factor and permittivity are often based on IEC 60250 [29]. 

But how can they be sure that conformity assessment activities are reliable When they comply with the criteria laid down in ISO/IEC standards and guides. 

King, B. (2001), Meeting the measurement uncertainty and traceability requirements of ISO/IEC standard 17025 in chemical analysis, Fresen. J. And. Chem., 371, 714. 

Section 5.4 of the ISO/IEC standard 17025 (ISO/IEC 2005) requires Testing laboratories shall have and shall apply a procedure to estimate the uncertainty of measurement, and in a test report where applicable, a statement on the estimated uncertainty of measurement information on uncertainty is needed in test reports when it is relevant to the validity or application of the test results, when a client s instruction so requires, or when the uncertainty affects compliance to specification limits (ISO/IEC 2005, section 5.10). Although the reporting clause leaves open the possibility of not including the measurement uncertainty of a result, I believe that the added value to the client of a proper measurement uncertainty statement far outweighs any temporary problems that may be caused by unfamiliarity with the measurement uncertainty concept. 

In the electrical field the International Electrotechnical Commission (IEC) performs the same function as ISO. The work of this body is of interest where rubbers are used in electrical insulation, etc. As regards electrical test methods for rubber, ISO and BSI have tended to adapt the basic procedures and principles standardised by IEC or to rely on the IEC standards. 

The usual standard methods for volume and surface resistivity both use the same test piece and electrode geometry and essentially the same measuring circuit. There are no ISO or IEC methods for rubbers but, where national standards specifically for polymers exist, they are usually adaptations of the IEC Publication 600931 for insulating materials in general. The relevant British Standards for rubbers are BS 903-C12 for surface resistivity and BS 903-C23 for volume resistivity. ASTM has an equivalent to the IEC standard for insulating materials generally, D2574, but no standard specifically for rubbers. 

The capacity of a motor is defined by the distance (mm) between its drive shaft and bed plate. This distance is termed its frame size. For asynchronous motors there is a standard (IEC standard) that defines frame size. For example, if a motor has a diameter of 800 mm, its frame size is 400. Motors produced according to this standard are termed standard motors. 

Analytical quality issues have gained a lot of ground over recent decades. Awareness of the importance of providing some sort of guarantee that a result is credible is becoming more and more popular in food laboratories worldwide. Today, the ISO/IEC Standard 17025 regulates much of what is mandatory or recommended for analytical laboratories in the preparation of the quality manual, which is in turn the first step towards accreditation. The main pillars of an analytical QC system (Fig. 3.7) are CRMs and PTs. Both are essential in the laboratory, since they satisfy different needs. There are several uses for both CRMs and PTs. Some points are described in the following sections. 

Figure 1.2 Test apparatus for ascertainment of maximum experimental safe gap according to IEC Standard 60079-1 A. a = interior sphere with a volume of 20 cm3...

Note The content of Table 2.2(a) describes the traditional classification (IEC standardization not incorporated). Until 1998 the USA and Canada adopted the three-zone concept for areas hazardous due to combustible gases, vapours and mist according to IEC 60079-10, in parallel with the content of Table 2.2(a). 

Note In parallel to the traditional protection methods described above, the USA and Canada have adopted most of the IEC Standards (see Table 3.14). 

A A type test according to IEC Standard 60529, category 1 (using artificial depression by a ventilator/vacuum pump) for the types of protection IP 5X or IP 6X... 

In the course of the integration of European states and the removal of trade barriers, national standardization loses importance considerably. The majority of electrical standards comes into existence by international cooperation with IEC, International Electrotechnical Commission, Geneva/Switzerland. On the basis of IEC Standards many European Standards have been developed in the past. This work has been done by CENELEC, Comite Europeen de Normalisation Electrotechnique, Brussels/Belgium. European Standards or Norms (EN) often deviate from their IEC origins in their technical content. To avoid double action and to ensure a more effective standardization procedure, IEC and CENELEC are now working in closer cooperation. CENELEC is a private organization and does not act as an institution of the European Union at all. This fact indicates that European Standards need a legal act to come into force. Members of CENELEC are the national committees for standardization of the member states (not identical with the European Union). 

As mentioned above, IEC Standards are adopted on a voluntary basis. Thus, compliance with IEC Standards does not guarantee free trading of explosion protected equipment worldwide. Today, mainly two blocks are attainable by compliance only with their own standards ... 

IEC Standards and national standards shall be identical if not, a transitional period (some years) will be necessary to achieve convergence of standards... 

Note Compliance is given between EN and VDE Standards IEC Standards do not fully comply with EN Standards... 

Overlooking the IEC standardization work, two standards exist for rooms or buildings respectively and analyser houses ... 

The International Electrotechnical Commission (IEC), based in Geneva, Switzerland, is voting on the first international CPV draft standard suitable for testing all of the CPV geometries and technologies. The IEC standard builds on the concept of... 

Quality management and Quality Assurance Standards. Guidelines for Selection and Use (ISO/IEC Standard 9000), International Organisation for Standardisation, Geneva. Switzerland (1990). 

The suitability of an enameled wire for a particular application depends to a very large extent on the thermal class to which it belongs. Classification of a wire according to the usual IEC standards is carried out primarily on the basis of its temperature index, breakdown voltage at nominal temperature, and the heat shock characteristics of the insulation. The IEC specifications are internationally binding. In many countries the national standards are completely IEC-harmo-nized. 

In late 1992, The Society of the Plastics Industry, Inc (SPI) s Polymeric Material Producers Division (PMPD) recommended that its member companies begin to convert to the use of internationally accepted standards developed by ISO and lEC for determining the properties of plastics and to routinely supply data on product datasheets and advertisements, using the preferred ISO/IEC standards, by June 1994. This strategic move was in response to the growing needs of various market sectors, led by the automotive industry. 

Quality Management and Quality Assurance Standards, Guidelines for selection and use, ISO/IEC. Standard 9000, International Organization for Standardization, 1987. 

Accuracy (trueness and precision) of measurement methods and results. Part 1 General principle part 2 A basic method for the determination of repeatability and reproducibility of standard measurement methods part 4 Basic methods for estimating the trueness of a test method Part 6 Practical application. ISO/IEC Standard 5725, International Organization for Standardization, draft, 1990. 

In order to promote international unification, IEC National Committees undertake to apply IEC International Standards transparently to the maximum extent possible in their national and regional standards. Any divergence between the IEC Standard and the corresponding national or regional standard shall be clearly indicated in the latter. 

MPEG-1 Refers to ISO/IEC standards 11172-1 (Systems), 11172-2 (Video), 11172-3 (Audio), 11172-4 (Compliance Testing), and 11172-5 (Technical Report). 

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