Standards used by TRaC for the evaluation include IEC, EN, UL and MIL/Aero standards. Detail about the standards used by TRaC in support of evaluation and certification is given below.

Evaluation

The process of evaluation includes:

  • Assessment of equipment design
  • Testing of a sample of the equipment

Both elements of the evaluation process will be conducted against an agreed standard or standards. The evaluation process is usually concluded with a detailed test report.

Certification

The process of certification includes all elements of the evaluation process (e.g. testing and assessment) but formally links the findings to the ongoing control of production of the equipment. Production control may be a:

  • Commitment by the manufacturer to follow certain certification rules
  • Routine audit of a sample of the equipment
  • Routine production control audits of the manufacturing process

The requirements for certification depend upon the certification scheme and in some cases legislative requirements (e.g. ATEX certification for Europe, Hazloc certification for USA).

Standards

The processes of evaluation and certification are normally conducted against published standards appropriate to the end application. Typical standards are:

  • IEC Standards – Published by the IEC for the global market. These standards are now the driver standards for global hazardous area approval. There has been a movement of late for national or regional standards (e.g. UL or EN) to adopt the IEC requirements with minimum deviation. Commonly used IEC standards are:
  • EN60079 series (electrical equipment – gases and dusts)
  • EN61241 series (electrical equipment – dusts)
  • EN standards – These are regional standards published by CENELEC and CEN for the European ATEX market. There have been recent changes in these standards (see article on Revision of accepted ATEX harmonised standards). For European (ATEX) certification, the following are commonly used standards:
    • EN60079 series (electrical equipment – gases and dusts)
    • EN61241 series (electrical equipment – dusts)
    • EN13463 series (mechanical equipment – gases and dusts)
    • EN13980 (ATEX production control)
  • UL standards – Published by UL for use with the hazardous locations (hazloc) scheme operated by the US Federal Occupational Health and Safety Administration (OHSA). These are national standards but are in the process of being harmonised with the IEC standards detailed above.
    Military standards – The main standard applicable to explosion prevention in potentially explosive defence applications is Mil-STD 810F. Section 511 of this standard details a test applicable to equipment for use in land, sea or airborne applications.
    Aerospace standards – The main standard applicable to explosion prevention in potentially explosive aerospace environments is RTCA standard DO-160F. Section 9 of this standard details a series of tests applicable to equipment for use in airborne or ground-based applications.