IEC 62957-1:2017

Radiation protection instrumentation - Semi-empirical method for performance evaluation of detection and radionuclide identification - Part 1: Performance evaluation of the instruments, featuring radionuclide identification in static mode

IEC 62957-1:2017 specifies requirements for data preparation and data injection when using the semi-empirical method for performance evaluation of detection and radionuclide identification. This document recommends approaches for results interpretation and consolidation and establishes a method to share data and analysis results. This part of the standard is specific to the performance evaluation of radionuclide identification in static mode, i.e. when measurement geometry does not change (e.g. radionuclide identification devices in start-stop mode).

Instrumentation pour la radioprotection - Méthode semi-empirique pour l'évaluation des performances de détection et d'identification de radionucléides - Partie 1: Evaluation de la performance des instruments avec l'identification des radionucléides en mode statique

L'IEC 62957-1:2017 spécifie des exigences relatives à la préparation et à l'injection de données dans le cadre de l'utilisation de la méthode semi-empirique pour l'évaluation des performances de détection et d'identification des radionucléides. Le présent document recommande des approches d'interprétation et de consolidation des résultats, et établit une méthode d'échange de données et de résultats d'analyse. La présente Partie concerne spécifiquement l'évaluation des performances d'identification des radionucléides en mode statique, c'est-à-dire lorsque la géométrie de mesure ne varie pas (par exemple, avec des dispositifs d'identification des radionucléides en mode démarrage-arrêt).

General Information

• Status: Published
• Publication Date: 19-Sep-2017
• ICS: 13.280 - Radiation protection
• Technical Committee: SC 45B - Radiation protection instrumentation
• Drafting Committee: PT 62957-1 - TC 45/SC 45B/PT 62957-1
• Current Stage: PPUB - Publication issued
• Start Date: 20-Sep-2017
• Completion Date: 14-Oct-2017

Standards Content (Sample)

IEC 62957-1 ®
Edition 1.0 2017-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Radiation protection instrumentation – Semi-empirical method for performance
evaluation of detection and radionuclide identification –
Part 1: Performance evaluation of the instruments, featuring radionuclide
identification in static mode
Instrumentation pour la radioprotection – Méthode semi-empirique pour
l'évaluation des performances de détection et d'identification de radionucléides –
Partie 1: Evaluation de la performance des instruments avec l'identification des
radionucléides en mode statique
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IEC 62957-1 ®
Edition 1.0 2017-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Radiation protection instrumentation – Semi-empirical method for performance

evaluation of detection and radionuclide identification –

Part 1: Performance evaluation of the instruments, featuring radionuclide

identification in static mode
Instrumentation pour la radioprotection – Méthode semi-empirique pour

l'évaluation des performances de détection et d'identification de radionucléides –

Partie 1: Evaluation de la performance des instruments avec l'identification des

radionucléides en mode statique

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 13.280 ISBN 978-2-8322-4822-5

– 2 – IEC 62957-1:2017 © IEC 2017
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms, definitions and abbreviated terms . 7
3.1 Terms and definitions . 7
3.2 Abbreviated terms . 9
4 General requirements . 10
5 Base material characterization and acquisition of input data . 10
5.1 General . 10
5.2 Base material characterization requirements . 10
5.3 Base material composition table requirements . 11
5.4 Raw spectra requirements . 11
6 Generation of base spectra from raw spectra . 11
6.1 General . 11
6.2 Base spectra data element requirements . 12
6.3 Sensitivity requirements . 13
7 Distortion modelling . 13
7.1 General requirements . 13
7.2 Acquisition of model parameters . 13
8 Generation of sample spectra . 14
8.1 Scenarios . 14
8.2 Group of scenarios. 14
8.3 Sample spectra . 14
9 Injection of sample spectra . 14
9.1 General requirements . 14
9.2 Replay software requirements . 14
9.3 Identification report requirements . 15
10 Data interpretation and consolidation . 15
10.1 Data interpretation . 15
10.2 Consolidated identification reports . 16
11 Validation . 16
11.1 General . 16
11.2 Equivalency between measured and sample spectra . 16
11.2.1 Requirements . 16
11.2.2 Method of test. 16
11.3 Equivalency between replay software and instrument-embedded software . 16
11.3.1 Requirements . 16
11.3.2 Method of test. 17
Annex A (informative) Example base material composition table . 18
Annex B (informative) Base spectra naming convention and format . 19
B.1 Naming convention for base spectra . 19
B.2 Example format for base spectra . 20
Annex C (informative) Distortion modelling . 21
Annex D (informative) Scenario . 23

Annex E (normative) Technique for sample spectra generation . 24
E.1 General . 24
E.2 Distortion . 24
E.3 Scaling-down . 24
E.4 Summing-up . 26
Annex F (normative) Identification report . 27
Annex G (informative) Acceptable response table example . 28
Annex H (informative) Guide to recommended identification report interpretation
scheme . 29
Annex I (informative) Consolidated identification reports . 33
I.1 Example of consolidated identification report by scenario (see Table I.1) . 33
I.2 Example of identification report consolidated by ability of instrument to
identify a given radionuclide under changing conditions (see Table I.2) . 33
Bibliography . 35

Figure C.1 – Reference and distorted spectra . 22
Figure E.1 – Scaling–down technique . 25
Figure H.1 – Recommended identification results interpretation scheme . 29

Table A.1 – Base material composition for base material isotopic composition . 18
Table B.1 – Naming convention for the base spectra . 19
Table I.1 – Consolidated identification report example . 33
Table I.2 – Example of identification report consolidated by material . 34

– 4 – IEC 62957-1:2017 © IEC 2017
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
RADIATION PROTECTION INSTRUMENTATION –
SEMI-EMPIRICAL METHOD FOR PERFORMANCE EVALUATION
OF DETECTION AND RADIONUCLIDE IDENTIFICATION –

Part 1: Performance evaluation of the instruments, featuring
radionuclide identification in static mode

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard 62957-1 has been prepared by subcommittee 45B: Radiation
protection instrumentation, of IEC technical committee 45: Nuclear instrumentation.
The text of this International Standard is based on the following documents:
FDIS Report on voting
45B/876/FDIS 45B/880/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.

This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 62957 series, published under the general title Radiation
protection instrumentation – Semi-empirical method for performance evaluation of detection
and radionuclide identification, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
– 6 – IEC 62957-1:2017 © IEC 2017
INTRODUCTION
There are known challenges associated with the application of traditional methods for the
performance evaluation of instruments used for the detection and identification of
radionuclides. These challenges mainly originate from test logistics and the resources
required for qualification type pass/fail tests.
As an alternative approach, a semi-empirical performance evaluation method has been
developed [1] . The concept of this technique, also known as injection study, is based on
computerized interpretation of detection or identification reports, obtained by injection of
processed data into instrument–specific replay software for detection or radionuclide
identification. The method does not prohibit the use of synthetic data if experimental data is
not available.
While remaining reasonably accurate, semi-empirical methods do not require significant
resources for performance evaluation. In some applications, where full scope performance
testing is not feasible or practical, the use of semi-empirical methods can provide reasonable
confidence in the instrument performance. By no means are semi-empirical methods meant to
fully replace traditional tests, but rather to complement them.
It is envisioned that this standard will comprise three parts. Part 1 of the standard is specific
to the performance evaluation of radionuclide identification in static mode, i.e. when
measurement geometry does not change.
Future parts of the standard will address detection and radionuclide identification in dynamic
scenarios.
___________
Instrumental tests.
Numbers in square brackets refer to the Bibliography.

RADIATION PROTECTION INSTRUMENTATION –
SEMI-EMPIRICAL METHOD FOR PERFORMANCE EVALUATION
OF DETECTION AND RADIONUCLIDE IDENTIFICATION –

Part 1: Performance evaluation of the instruments, featuring
radionuclide identification in static mode

1 Scope
This part of IEC 62957 specifies requirements for data preparation and data injection when
using the semi-empirical method for performance evaluation of detection and radionuclide
identification. This document recommends approaches for results interpretation and
consolidation and establishes a method to share data and analysis results.
This part 1 of the standard is specific to the performance evaluation of radionuclide
identification in static mode, i.e. when measurement geometry does not change (e.g.
radionuclide identification devices in start-stop mode).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements of this document. For dated references, only the edition
cited applies. For undated references, the latest edition of the referenced document (including
any amendments) applies.
IEC 60050-395:2014, International Electrotechnical Vocabulary (IEV) – Part 395: Nuclear
instrumentation: Physical phenomena, basic concepts, instruments, systems, equipment and
detectors
IEC 62755:2012, Radiation protection instrumentation – Data format for radiation instruments
used in the detection of illicit trafficking of radioactive materials
ISO 8601:2004, Date and time format
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-395 apply, as
well as the following.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1.1
acceptable response table
list of expected radionuclide identification result(s) reported by the instrument or its replay
software
– 8 – IEC 62957-1:2017 © IEC 2017
3.1.2
base material
radioactive material that contains one or several radionuclides of known isotopic composition
3.1.3
base material composition table
list of radionuclide(s) that are present in each of the base materials in a sufficient quantity for
radionuclide identification by gamma-ray spectrometry
3.1.4
base spectrum
processed raw spectrum used as an input for the generation of sample spectra
3.1.5
confidence index
measure provided by the instrument of the reliability assigned to the radionuclide identification
results
Note 1 to entry: Higher values indicate a higher likelihood of the presence of the radionuclide(s), or group of
nuclide(s).
3.1.6
confidence index threshold
minimum level of reliability of the radionuclide identification result (i.e. minimum value of the
corresponding confidence index) that is required for an isotope to be indicated as present
3.1.7
distortion model
result of distortion modelling evaluation, generally a formula describing how spectra from a
given instrument model are affected by a given non-ideal environmental condition
3.1.8
distortion modelling
evaluation of the functional relationship between pulse heights in the non-distorted and
distorted spectra acquired under specific environmental, electromagnetic, or other conditions
3.1.9
false negative result
detection or radionuclide identification result that was not reported although it was expected
to be
3.1.10
false positive result
detection or radionuclide identification result that was reported although it was expected not
to be
3.1.11
detection (identification) report
file containing all detection (radionuclide identification) results generated by an instrument’s
replay software upon injection of a sample spectrum
3.1.12
identification result
name of a radionuclide or aggregate material which has been identified. It is one item of the
identification report
3.1.13
influencing factor
quantity that is not the measurand but that affects the result of the measurement
3.1.14
injection
process of submitting processed data (sample spectra) to the replay software for detection
and/or radionuclide identification
3.1.15
raw spectrum
gamma ray spectrum of base material obtained with high statistical accuracy by the
instrument under evaluation
3.1.16
replay software
software that utilizes the detection and/or radionuclide identification analysis algorithm of a
particular instrument model on the computer used for injection to create a detection or
identification report corresponding to an injected sample spectrum
3.1.17
sample spectrum
instrument–specific amplitude spectrum produced by processing one or more base spectra for
injection
3.1.18
scenario
description of the test conditions
Note 1 to entry: for example:
– presence of one or several base material(s) and the given ambient gamma dose equivalent rate for each;
– acquisition time;
– presence of influencing factor(s).
3.1.19
semi-empirical performance evaluation
process of injection of the processed measured data into the instrument–specific replay
software for analysis followed by computerized interpretation and consolidation of the results
3.1.20
sensitivity
ratio of the net total count rate (cps) to the known ambient gamma dose equivalent rate
(μSv/h) due to exposure to the given base material by independent means obtained either by
calculation or by measurement using a calibrated instrument
3.2 Abbreviated terms
ASCII American standard code for information interchange
cps counts per second
EMI electromagnetic interference
MCA multichannel analyser
HEU highly-enriched uranium
LEU low-enriched uranium
NORM naturally occurring radioactive materials
PET positron emission tomography

– 10 – IEC 62957-1:2017 © IEC 2017
PMMA polymethyl methacrylate
FN false negative
FP false positive
RGPu reactor grade plutonium
WGPu weapons grade plutonium
XML extensible markup language
UTF universal character set transformation format
4 General requirements
The semi-empirical performance evaluation method shall consist of the following steps:
– base material characterization and acquisition of raw spectra;
– generation of base spectra from raw spectra;
– distortion modelling;
– generation of the sample spectra according to predefined scenarios;
– injection of the sample spectra into the replay software;
– interpretation and generalization of the radionuclide identification results;
– validation.
Guidance for choosing the base materials can be taken from the relevant standards
(e.g. IEC 62327 [3]).
The base spectra, base material composition table, distortion model and replay software shall
meet the requirements of this document. The manufacturer shall provide the full list of all
possible messages (e.g. identification results) which might appear as the results of
radionuclide identification along with a detailed explanation of the meaning of each message.
This will enable interpretation of the identification results. One or more instruments shall be
used for experimental validation of the semi-empirical performance evaluation results.
A detailed description of the process and relevant requirements are given in the following
clauses.
NOTE This method does not account for pileup or increased dead time due to high count rates.
5 Base material characterization and acquisition of input data
5.1 General
The semi-empirical performance evaluation method initially requires base material
characterization and input data acquisition. Input data consists of raw spectra and static
efficiencies for the instrument(s) under evaluation.
5.2 Base material characterization requirements
All base materials shall be characterized with a high-resolution gamma spectrometer to
assess their radionuclide composition. Characterization spectra shall be formatted according
to IEC 62755 and provided by the manufacturer, or organization owning the base material,
along with the date on which the spectrum was taken. Care should be taken that the base
materials do not show significant impurities. If the base material has impurities that can be
identified by the instrument, then those radionuclides might appear in the replay software or
instrument identification results, and shall be accounted for in the base materials list.
Information on sources used should be provided and distributed with the corresponding base

spectra. This will include relevant information such as mass, shape, density and chemical
composition (e.g. metal or oxide).
5.3 Base material composition table requirements
The manufacturer or owner of the base material shall provide a base material composition
table describing the radionuclide composition of each base material and the measured and
validated activity of each source, along with the measurement’s date and uncertainty of the
measured activity. For the purpose of naming base materials that contain significant
quantities of daughter elements, the name of the parent radionuclide shall be used. An
example base material composition table is given in Annex A.
5.4 Raw spectra requirements
Raw spectra shall be collected for each base material, including natural radiation background,
using the instrument under evaluation. To the extent possible, the same instrument should be
used throughout the collection effort.
Conditions for acquisition of the raw spectra shall, to the extent possible, be similar to static
operational conditions. Commerce material containing NORM shall be used in bulk form to
account for radiation scattering and self-absorption processes.
6 Generation of base spectra from raw spectra
6.1 General
Radiation background shall be subtracted from all spectra, except the spectrum of natural
radiation background. Prior to this subtraction, the spectra shall be adjusted to account for
differing live times and re-binned as needed to account for any gain shifts. The background
subtracted spectrum for each base material becomes the base spectrum. Each base spectrum
shall be typical for the model being used (e.g. consideration of differences in energy
resolution, low-level discriminators and variation in calibrations).
Base spectra should be named according to Annex B. They should be formatted according to
IEC 62755. An example is given in Annex B.
All base spectra shall be defined over the same number of MCA channels and shall have the
same energy calibration.
If the instrument under evaluation is designed to identify shielded radionuclide(s), the base
spectra of shielded material should be obtained.
Whenever possible, the ambient gamma dose equivalent rate produced by the base material
at the instrument under evaluation should be at least 10 times greater than that of
background.
Acquisition times for raw spectra shall be adjusted such that the base spectra they are
processed into contain at least ten times the number of counts contained in any individual
sample spectrum expected to be generated from them. This should be according to the
formula:
D T ≥ 10 D T (1)
0 0 s s
– 12 – IEC 62957-1:2017 © IEC 2017
Where:
D is the dose rate produced by the base material at the distance at which the base
spectrum was collected;
T is the live time of the base spectrum;
D is the maximum dose rate to be simulated in the sample spectra;
s
T is the maximum live time to be simulated in the sample spectra.
s
Care should be taken to ensure that the dead time is as low as possible to avoid pileup, but
no more than 2 %. As these raw spectra are collected over long periods of time, care should
also be taken to avoid conditions which can lead to gain shifts.
6.2 Base spectra data element requirements
The following data elements shall be included in each base spectrum:
• : Real time in the format “PT1H15M05.2S”, “PT75M5.2S”, or
“PT4505.2S”.
• : Live time in the format “PT1H15M05.2S”, “PT75M5.2S”, or
“PT4505.2S”.
• : Energy calibration information that spectrum measurements can
reference as applicable to a particular spectrum. There are two methods available for
providing energy calibration information: either in the form of a second-order polynomial
equation in which the CoefficientValues child element shall be specified, or in a table in
which the EnergyBoundaryValues child element shall be specified. Only one of the two
methods applies to a particular energy calibration. The EnergyDeviationValues and
EnergyValues child elements provide a means to account for the difference in the energy
predicted by the second-order polynomial equation and the true energy.
• : The measured ambient radiation dose equivalent rate value in µSv/h.
• : A list of values, one for each of a spectrum’s channels. The values
represent the number of counts per channel.
• : a ratio of the net total count rate (cps) to the known ambient gamma dose
equivalent rate (μSv/h) due to exposure to the given base material by independent means
obtained either by calculation or by measurement using a calibrated instrument. Parent
element: .
• : Time corresponding to the start of the collection of the data contained in
the base spectrum. This should be in the format “2004-11-03T14:36:04.3-06:00”, where
“-06:00” represents the difference between universal coordinated time and local time.
For the time format, the number preceding “H” gives the hours of the measurement duration,
the number preceding “M” gives the minutes of the measurement duration and the number
preceding “S” gives the seconds of the measurement duration. This duration can be
expressed with hours, minutes and seconds or can be expressed as minutes and seconds or
seconds only. This is according to ISO 8601.

Additionally, the following data elements should be recorded:
• : The name of the radiation detector.
• : The radionuclide used to obtain the base spectrum.

• Neutron counts: Number of neutron counts collected over the duration of the
measurement. This should be stored under a tag as in the following
example:

PT3.08
2

6.3 Sensitivity requirements
The sensitivity of the instrument to the given base material shall be obtained with an
uncertainty of less than 20 % (with a confidence level of 95 %).
The position of the instrument under evaluation shall be determined based on accuracy
requirements. The instrument’s orientation with respect to the source shall be the same as
how it is intended to be used in the field. Raw spectra shall be acquired at a count rate where
the effects of pile-up are negligible.
The sensitivity shall be calculated according to formula (2).
net _count _rate (cps)
(2)
Sensitivity=
ambient _gamma _dose _equivalent _rate (mSv /h)
Obtained sensitivities for each base material shall be included in the base spectra under the
element as shown in Clause B.2.
7 Distortion modelling
7.1 General requirements
To assess an instrument’s tolerance to specified influencing factors, distortion modelling
should be obtained. Distortion is defined as the change in position of the peaks in the
spectrum due to influencing factors. Some common influences affecting the instrument’s
energy scale are temperature, magnetic field and high count rate. Other influences can be
modelled as desired.
The file containing the parameters of the distortion model shall be named and formatted
according to Annex C.
7.2 Acquisition of model parameters
The generic process of distortion modelling is as follows:
– Establish the reference peak centroid values from the spectra under normal test
conditions ; At a minimum, three peaks, covering nearly the full energy range shall be
241 137
Am, 661,5 keV from Cs, and 2 614 keV
used for the modelling (e.g. 59,5 keV from
from Th decay chain).
– Keeping all other conditions the same as that for the reference spectra expose the
instrument to the influence and obtain influence spectra using the same process as that
used to establish reference spectra.
___________
Conditions established in the standard applicable to the instrument type.

– 14 – IEC 62957-1:2017 © IEC 2017
– Obtain polynomial coefficients for the distortion model from the peak shifts between the
mean position of the peaks in the reference spectra and the positions of these same peaks
in the influence spectra, as described in Annex C.
8 Generation of sample spectra
8.1 Scenarios
Scenarios define the semi-empirical performance evaluation method test conditions. Each
scenario shall contain the acquisition time, individual dose equivalent rate from each base
material and background involved and the presence of influence(s), when applicable. Each
scenario shall have a unique name. Scenario names shall be used to name the corresponding
sample spectra and identification reports. Files containing scenarios should be formatted
according to Annex D.
8.2 Group of scenarios
Evaluation of the instrument performance might involve a large number of various scenarios.
Logically connected scenarios can be grouped into a group of scenarios for the convenience
of handling a large amount of data.
Scenarios in a group might target a specific aspect of the instrument’s performance, such as
its ability to identify innocent radioactive materials or shielded materials. There might be one
or several groups of scenarios, each corresponding to specific test procedures established by
international (e.g. IEC 62327 [3]) standards.
8.3 Sample spectra
Sample spectra are generated from the base spectra to simulate the measured spectra which
would be acquired under the conditions specified by the given scenario. For the same
scenario, a minimum of 100 individual sample spectra shall be generated to ensure statistical
confidence of the performance evaluation results.
NOTE The total counts obtained from the base spectra defines the maximum counts for the development of the
sample spectra.
The algorithm to generate a sample spectrum shall be compliant with the process described in
Annex E. The process described consists of spectrum distortion, scaling down and
summing-up processes and ensures a level of statistical variation in accordance with those
expected in measured spectra.
Each sample spectrum shall be formatted according to IEC 62755 (see the example of the
base spectrum in Annex B). The name of each sample spectrum shall be unique for the
scenario it corresponds to and contain the scenario name and its sequential number.
9 Injection of sample spectra
9.1 General requirements
If the instrument’s radionuclide identification algorithm requires injection of the radiation
background sample spectrum, this spectrum should be obtained and injected as required.
9.2 Replay software requirements
The replay software shall read sample spectra files, process the data in these files and record
identification report files.
The replay software shall not disclose any proprietary information about an instrument’s
radionuclide identification algorithm.
Replay software shall:
a) use a radionuclide identification algorithm (including its library of nuclides) that is
functionally equivalent to the instrument–embedded algorithm;
b) read a sample spectrum and perform a radionuclide identification;
c) run in a batch mode in order to open and analyse all spectra in the selected folder;
d) generate one output file (i.e. identification report) for each injected sample spectrum, save
it in the specified folder under the name of the analysed sample spectrum but with the
extension *.res.
The replay software shall record the radionuclide identification algorithm version and the
minimum necessary information about algorithm configuration in the identification report.
The replay software package shall be self-contained, in that it includes all components
necessary for it to run.
9.3 Identification report requirements
The data in the identification report should be UTF-8 characters encapsulated using the
extensible mark-up language (XML). An example of this file is given in Annex F.
The names of the individual radionuclides or group of radionuclides recorded in the
identification reports shall be identical to those defined in the acceptable response table. The
acceptable response table is discussed further in 9.1 and Annex G.
10 Data interpretation and consolidation
10.1 Data interpretation
The expected identification results for all base materials shall be defined for data
interpretation in a computer-readable data format according to Annex G.
The content of the acceptable response table shall contain the following information:
– radionuclide composition for the given base material described in the base material
composition table;
– expected results for radionuclide identification, e.g. those that shall be reported for this
particular base material and those that can be reported without considering them being
false positive results;
– naming convention.
Interpretation of identification reports can be performed according to the scheme in Annex H.
Its paradigm takes into consideration a degree of consistency between actual and expected
results of radionuclide identification allowing for the establishment of flexible scoring schemes
and for troubleshooting.
Interpretation of the identification report might involve analysis of confidence indices
associated with the reported identification results. The confidence index shall be reported on
a scale of 0 to 10. Identification results below a certain confidence index
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