Characteristic evaluation for radiation measuring instruments

Instrument classes

The standard follows the instrument, not the radiation. A gamma survey meter, a gamma personal dosimeter and an installed gamma area monitor are evaluated under three different standards. One evaluation tool is available today; the other classes are covered as reference material.

These are a part of what IEC subcommittee SC 45B publishes. The standards section lists its working groups and the full catalogue.

One instrument class has an evaluation tool so far, implementing the eight radiation characteristics of IEC 60846-1:2009, for portable survey meters, dose rate meters and area monitors. Enter reference values and indications; it computes relative response, coefficient of variation, combined standard uncertainty and the outcome per test point. Clause numbers are cited for reference — the standard itself must be obtained from the publisher.

• § 8.4.2

  Energy response

  Relative response across photon energies, referenced to the reference radiation quality.

• § 8.4.2

  Angular response

  optional

  Relative response as the angle of incidence departs from the reference direction.

• § 8.7

  Linearity

  Relative response over the measuring range, from the reference point up to nine check points.

• § 8.7

  Statistical fluctuation

  Coefficient of variation per point, evaluated against the stepped limit derived from the lower limit of the measuring range.

• § 8.8.2

  Overload

  optional

  Behaviour during and after exposure well above the measuring range.

• § 8.9.2

  Response time

  optional

  Time to reach 90 % of the final reading after a step change, and the reading 60 s later.

• § 8.11

  Dose rate dependence

  optional

  Relative response as the dose rate varies at a fixed radiation quality.

• § 8.13

  Alarm accuracy

  optional

  Whether the alarm stays silent below and triggers above the set threshold.

Standards

Radiation measuring instruments are standardised by IEC TC 45 / SC 45B, and the standard follows the instrument class. Each class is treated the same way here: the standard's own page first, then its test procedures, then a tool. Of the 8 standards described, 1 has an evaluation tool so far — IEC 60846-1:2009.

Electronic personal dosimeters, environmental monitoring stations, neutron survey meters and contamination meters each have their own standard. The standards section identifies the committee, its working groups and which standard applies to which instrument.

Regional and national adoptions carry later publication dates, which is a common source of confusion when a report cites a year that does not match the international edition. Each standard's page shows that edition as published.

This site is independent and is not affiliated with the IEC. It cites clause numbers and describes methods in its own words; it does not reproduce the text or tables of the standard.

Documentation

What the tools do, the standards behind them, the instrument classes they apply to, and the reference material around them. Written in our own words; clause numbers are cited for reference. Test procedures sit under the standard that specifies them.

• 🧮Evaluation tools What the tools compute, which instrument class can be evaluated today, and what each planned one still needs before it can be built.
• 📑IEC standards The IEC, the committee that writes the standards for radiation measuring instruments, its working groups, and a page for each standard covered — with its test procedures.
• 📟Instruments by purpose Protection instruments and quality control instruments — form, quantity, performance requirements and the governing IEC standard.
• 📖Guides Reference material that applies whichever standard you work to — operational quantities, radiation qualities, measurement uncertainty, interpretation of results.