IEC 62598:2011

Overview

IEC 62598:2011 - "Nuclear instrumentation - Constructional requirements and classification of radiometric gauges" - specifies safety and classification requirements for electrical measuring systems and instruments that use radioactive sources (radiometric gauges) and for associated source housings. The standard focuses on radiation protection and constructional requirements for fixed gauges (not related to power production or the fuel cycle). It cancels and replaces IEC 60405 and introduces updated classification, testing and labelling provisions.

Key Topics and Requirements

• Scope & exclusions: Applies to fixed radiometric gauges and stand‑alone source housings; excludes portable gauges and X‑ray tube systems (though principles may be applied analogously).
• Gauge classification: Defines three categories:
  • Category A - gauges with restricted (collimated) beams.
  • Category B - gauges with omnidirectional beams.
  • Category C - stand‑alone source housings for fixed gauges (new in this edition).
• Dose rate classes and temperature classes: Introduces standardized dose rate classes (replacing former “radiation protection class”) and temperature classes for environmental suitability.
• Fire resistance: Adds fire resistance classes and related test requirements for source housings and shutters.
• Constructional requirements: Specifies requirements for measuring gaps, source holders, source housings, beam alignment, detector housings and measuring heads to ensure safe containment and operation.
• Radiation protection measures: Prescribes shielding, shutter design, and protection against unauthorized use, including indication of shutter position and optional warning devices.
• Testing and measurement: Details procedures for dose equivalent rate measurements (closed and open shutter conditions), temperature cycle tests, mechanical and fire resistance tests.
• System coding and labelling: Defines a system classification code (including revision and fire-test digits) and labelling requirements; includes documentation and installation guidance (Annex A).

Keywords: IEC 62598, radiometric gauges, constructional requirements, source housings, dose rate classes, radiation protection, fire resistance, testing.

Practical Applications and Users

Who uses IEC 62598:

• Manufacturers and designers of fixed radiometric gauges and source housings - to design compliant products.
• Installation and maintenance engineers - for correct installation and verification of shielding, alignment and safety devices.
• Radiation protection officers and safety managers - to assess dose rates, signage and emergency measures.
• Certification and conformity bodies - to perform tests and label systems according to the classification code. Practical applications include level, density and thickness gauges in industrial process control where sealed radioactive sources are used.

Related Standards

Relevant normative references cited in IEC 62598 include:

• IEC 60476, IEC 60692, IEC 60846‑1/2, IEC 60982, IEC 61005, IEC 61010‑1, IEC 61326, IEC 61336
• ISO 921, ISO 2919
• IEC 60050‑394 (terminology) Consult these documents for detector/test methods, dose meters, and source classification details.