Title Ionising Radiations Instrumentation Specialisation
Type Stage Two
Code HPE115
Requirement Optional

Module objective

By the end of this module the Clinical Scientist in HSST will have acquired the knowledge and experience necessary to achieve a certificate of competence as an Ionising Radiations Instrumentation Specialist (IRIS) from an approved body. Employers may take advice from an IRIS in areas that require significant expertise in radiation instrumentation, such as calibration requirements and selection of appropriate instrumentation. The Clinical Scientist in HSST will have the knowledge, skills and experience to undertake the role of an IRIS for medical radiation equipment (e.g. for radiotherapy, diagnostic radiology, nuclear medicine and/or other use of radioactive sources). The Clinical Scientist in HSST will be able to critically appraise organisational governance for relevant radiation measuring equipment programmes and advise on regulatory compliance.

Knowledge and understanding

By the end of this module the Clinical Scientist in HSST will analyse, synthesise, evaluate and critically apply their expert knowledge with respect to radiation measuring equipment, including all of the areas required by the IRIS certification body to be awarded an IRIS certificate [1], including:

  • Practical radiation fields.
  • Spectra emitted from various source types.
  • Change in energy of scattered radiation.
  • Change in energy of attenuated radiation.
  • Generation of Bremsstrahlung radiation.
  • P factor for contamination, detection and measurement methods (including uncertainties and limits of detection), quantities and units (including dosimetry underlying regulatory quantities).
  • National and international regulations, guidance and standards, including:
    • ISO 4037 or current equivalent standard;
  • IRR99 regulation 19 or current regulation dealing with the selection, use, maintenance, or testing of radiation instrumentation; legal and regulatory basis;
  • relevant current NPL Good Practice guides.
  • Quantities and units, including:
    • primary physical quantities;
    • limit quantities;
    • operational quantities;
    • activity (per unit area, per unit volume, per unit mass);
    • principles of operation of radiation measuring equipment;
    • detection and measurement.
  • Monitoring methods, including statistical and mathematical techniques relevant to analysis of radiation detector performance.
  • Signal processing and display.
  • Power supplies, including consideration of internal high voltages.
  • Calibration facilities, including traceability to national standards, types of facility and their essential attributes, including those for gamma, X-ray, beta, neutron and surface contamination measurement.
  • Typical instrument problems.
  • The effect the environment can have for both calibration and routine operation, including: temperature; pressure; humidity; radon; Electromagnetic Compatibility (EMC); vibration and impact; bright light; magnetic fields; pulsed fields.
  • Quality control, audit and record keeping.
  • Transport of radioactive materials.

Technical and clinical skills

By the end of this module the Clinical Scientist in HSST will be able to perform, adapt and master the technical procedures required of an IRIS and will:

  • Give formal advice on the application of national and international standards publications (e.g. National Physical Laboratory (NPL) Measurement Good Practice Guide No. 14, ISO, BS EN, IEC).
  • Synthesise and evaluate differing and innovative options for management of radiation measuring equipment (including calibration and maintenance) in the medical specialty and implement such a programme in accordance with the requirements of the Ionising Radiations Regulations 1999 regulation 19 and relevant parts of the Approved Code of Practice and Good Practice Guidance, or other relevant legislation.
  • Evaluate suitability of a variety of radiation measuring equipment for a range of activities, demonstrating a detailed understanding of the principles of operation of ion chambers, proportional counters, Geiger-Müller (GM) detectors, scintillators and solid state detectors, including:
    • the limitations associated with different instruments;
    • the associated monitoring techniques that can be utilised to mitigate for any less desirable instrument characteristics.
  • Develop robust and traceable procedures for calibration of a variety of radiation monitoring equipment in accordance with relevant standards.
  • Apply expert knowledge of fluence, air kerma, absorbed dose, ambient, directional, personal and effective dose equivalents, activity, activity per unit area, activity per unit volume and activity per unit mass.
  • Apply to at least one type of calibration facility expert knowledge of traceability, levels of uncertainty associated with the establishment of the calibration reference field and how these factors relates to the final instrument response figure derived.
  • Synthesise and evaluate the mathematical uncertainties in the calibration protocols for a variety of instruments.
  • Perform fault analysis for a variety of monitoring equipment and advise on remediation, including the impact on previous radiation safety assessments for staff, patients, or members of the public, including:
    • identification of common modes of failure;
    • the effect that the failure has on the use of the instrument;
    • the required scope of test after repair.
  • Perform, analyse, report and present audits of the calibration programme.
  • Expertise in setting up a range of instrument types.
  • Synthesise and evaluate comprehensive advice on appropriate instrument selection.

The Clinical Scientist in HSST will also be expected to reflect on the challenges of applying research and innovative technologies to practice in relation to these procedures and suggest improvements, building on a critique of available evidence.

By the end of this module the Clinical Scientist in HSST will apply their detailed knowledge and understanding with respect to ionising radiation instrumentation to a range of clinical environments and provide IRIS advice to colleagues and patients.

Attitudes and behaviours

By the end of this module the Clinical Scientist in HSST would be expected to demonstrate the attitudes, behaviours and insights required of a Consultant Clinical Scientist working within the limits of professional competence, referring as appropriate to senior staff, and be able to:

  • Appreciate the impact of current clinical and scientific outcomes for the medical IRIS in relation to patients, members of staff and members of the public.
  • Adhere to, and accept and work within current governance requirements applicable within an organisation, raising concerns when necessary.
  • Promote the importance of innovation in service and/or delivery including the contribution of research and innovation in radiation instrumentation to the NHS, business and the UK economy.
  • Engage service users, patients and the public to promote the positive impact of expert radiation instrumentation advice from a certified IRIS.
  • Display an objective and unbiased approach.



  1. RPA 2000. The Competence Certification Schemes. Certification as an Ionising Radiations Instrumentation Specialist (IRIS). Document IRIS2. Instructions for the creation of the Portfolio of Evidence for Certification as an Ionising Radiations Instrumentation Specialist (IRIS), published 21 February 2011. uctions21Feb11.doc
  2. Measurement Good Practice Guide No. 14. The Examination, Testing and Calibration of Portable Radiation Protection Instruments. published March 1999 by National Physical Laboratory.


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