ISO/DIS 18436-9:2025(en)

ISO/TC 108/SC 5

Secretariat: SA

Date: 2025-05-22

Condition monitoring and diagnostics of machine systems — Requirements for training and certification of personnel —

Part 9: Optical Gas Imaging

© ISO 2025

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Contents

Foreword 3

1 Scope 4

2 Normative references 4

3 Terms and definitions 4

4 Certification of Personnel 4

4.1 General 4

4.2 Category I 4

4.3 Category II 5

4.4 Category III 5

5 Eligibility 6

5.1 General 6

5.2 Education 6

5.3 Training 6

5.4 Experience 7

6 Examinations 7

6.1 Examination content 7

6.2 Conduct of examinations 8

Annex A (normative) Examination content and training syllabus 1

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.

The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.

ISO 18436-1 was prepared by Technical Committee ISO/TC 108, Mechanical vibration, shock and condition monitoring, Subcommittee SC 5, Condition monitoring and diagnostics of machine systems.

The document ASNT Recommended Practice SNT-TC1A (2024), “Personnel Qualification and Certification in Nondestructive Testing” was used as a reference for testing the visual acuity of candidates.

Condition monitoring and diagnostics of machine systems — Requirements for training and certification of personnel
Part 9: Optical Gas Imaging

This part of ISO 18436 specifies sector specific requirements for organizations (certification bodies) operating conformity assessment systems who perform Optical Gas Imaging inspections to identify fugitive emissions (e.g, but not limited to, hydrocarbons, ammonia, sulphur hexafluoride, carbon monoxide, carbon dioxide, refrigerants) and who may recommend corrective action.

The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 13372, Condition monitoring and diagnostics of machines — Vocabulary

ISO/IEC 17000:2004, Conformity assessment — Vocabulary and general principles

ISO 18436‑1, Condition monitoring and diagnostics of machine systems — Requirements for certification of personnel — Part 1: Sector specific requirements for certification bodies and the certification process

For the purposes of this document, the terms and definitions given in ISO/IEC 17000, and ISO 18436-1 apply.

sUAS when referenced in this document, refers to small Unmanned Aerial Systems.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https://www.iso.org/obp

— IEC Electropedia: available at https://www.electropedia.org/

Certified persons are not only to have the knowledge areas covered in Annex A & B shall have the knowledge, skills, and aptitude to adequately perform the job tasks for the appropriate categories as indicated in clauses 4.2, 4.3, and 4.4.

Individuals certified to Category I can perform Optical Gas Imaging according to established and recognized procedures. Personnel certified to Category I shall be able to:

a) apply a specified optical gas imaging technique (e.g. utilize enhanced gas detection mode);

b) set up and operate the optical gas imaging equipment needed for safe data collection (e.g. fixed, portable or aerial platforms);

c) identify, prevent and control poor data collection and potential error sources;

d) identify and follow an established inspection route;

e) identify gas leaks and fugitive emissions using established instructions;

f) record and document gas leaks and fugitive emissions using established instructions;

g) record and document the environmental conditions at the time of the test (e.g. ambient air temperature, humidity, wind speed and direction;

h) verify that the background temperature (ΔT ) at the time of the inspection is suitable for obtaining good data;

i) adjust the image as needed to highlight the gas leak/fugitive emission;

j) select an appropriate optical gas imaging mode (e.g. auto, manual, enhanced) for successful gas detection;

k) perform instrument verification check as required by established instructions and/or regulatory requirements;

l) perform any required optical gas imaging camera maintenance (e.g. camera body and lens cleaning) to ensure successful emission detection;

m) report inspection results;

n) comply with all appropriate safety protocols;

o) comply with all local and national regulations regarding aerial platforms.

Individuals certified to Category II can perform optical gas imaging according to established and recognized procedures. Personnel certified to Category II shall be able to perform all the duties of a Category I and shall be able to:

a) determine the type of gas/fugitive emission that may be leaking;

b) analyse gas absorption/transmission curves or gas response factors and select the appropriate optical gas imaging camera;

c) create safe inspection routes that assure 100 % inspection coverage;

d) identify and document difficult to monitor (DTM) and impossible to monitor (ITM) components prior to and/or during an inspection;

e) locate/identify/quantify the source of the gas leak/fugitive emission;

f) maintain the calibration of the optical gas imaging equipment based on the manufacturer’s recommendations;

g) measure emissivity and reflective background per established techniques;

h) measure temperatures of components as required by established techniques;

i) establish the minimum and maximum safe altitudes for aerial platforms;

j) prepare inspection reports;

k) maintain a database of inspection results; and

l) provide guidance to and supervise Category I.

Individuals certified as Category III can perform optical gas imaging according to established and recognized procedures. Personnel certified to Category III shall be able to perform all the duties of a Category II and shall be able to:

a) develop and establish Optical Gas Imaging inspection programs, write inspection procedures and instructions, determine frequency of testing, identify systems/components for periodic/continuous monitoring and the use of advanced detection techniques;

b) assess the severity and compare to established acceptance criteria;

c) interpret and provide leak quantification calculations as required;

d) interpret and evaluate codes, standards, specifications, regulations and procedures;

e) designate the inspection methods, procedures and instructions to be used;

f) provide guidance and supervise Category I and II personnel;

g) recommend the use of alternative or supplemental leak detection technologies;

h) be able to establish and manage leak detection programs;

i) develop and implement Optical Gas Imaging inspection safety protocols.

NOTE: It is the employer’s responsibility to ensure Category III personnel have the necessary competency in the required management skill, for example creating budgets, preparing cost justifications, and managing personnel development as required.

Candidates should have a combination of education, training, and experience to ensure that they understand the principles and procedures applicable to optical gas leak detection and analysis.

It is advised that all candidates have their colour perception assessed by the Ishihara 24 plate test. A record of test results should be retained and presented to the assessment body upon request. In the event of a color perception deficiency, indicated by misreading four or more of the 24 plates is detected during the Ishihara test, a further “task specific” test is to be carried out by an appropriate entity. Failure to pass this test may require the candidate to use a monochrome palette. This “task specific” test and any requirements to use a monochrome palette is to be documented and made available to the assessment body upon request.

Candidates seeking certification do not need to provide evidence of formal education to establish eligibility. However, it is recommended that candidates for Category I and Category II have at least a secondary school graduate certification or its equivalent. Category II and III candidates shall be able to manipulate simple algebraic equations, use a basic scientific calculator and be familiar with the operation of personal computers. Successful completion of two or more years of mechanical technology, mechanical engineering, chemical engineering or petroleum engineering at an accredited college, university or technical school is highly recommended for candidates seeking certification to Category III.

To be eligible to apply for certification based on this part of ISO 18436, the candidates shall provide evidence of successful completion of training based on the requirements of Annex A. The documents listed in the Bibliography should be used as the domain of knowledge for the training syllabus. Such training shall be compliant with ISO 18436-3. The minimum duration of training is shown in Table 1. Training should be in the form of lectures, demonstrations, practical exercises, or formal training courses. Certification requirements shall be in accordance with this part of ISO 18436. Training time devoted to each subject shall be in accordance with Annex A and Table 1. See Annex B for a non-exhaustive list of the topics and subtopics to be covered. The curriculum may be adjusted for specific applications (buildings, sUAS, electrical, etc.) if the total hours and broad subject matters are covered.

Table 1 — Minimum duration of cumulative training (hours)

Training may be modularized into two or more subject areas covering general scientific principles and application-specific knowledge to allow for mutual recognition between non-destructive testing, condition monitoring and optical gas imaging bodies.

The operation of small unmanned aerial systems (sUAS) for optical gas imaging requires unique skills and knowledge. Supplementary training in the operation of such systems should include selection of the proper payload; scanning speed, height above ground level for imaging, height above ground level for measurement, proper sUAS positioning to minimize solar reflections, ability to recognize solar loading and competency in local sUAS regulations, including any needed licensing.

To be eligible to apply for assessment based on this part of ISO 18436, the candidate shall provide evidence to the ISO 18436-1 certification and body of experience in the field of Optical Gas Imaging in accordance with Table 2. Certification to Category II and III requires previous certification at the lower category.

Table 2 — Minimum cumulative practical, interpretation and program management experience requirements (months)

5.4.1 The minimum total experience durations specified (in months) are required to enable the acquisition of experience in all category criteria in accordance with ISO 18436-1 and clause 5.4.

5.4.2 Candidates shall keep verifiable documentary evidence of hours and nature of work for their Optical Gas Imaging inspections and reporting in accordance with ISO 18436-1. Candidates for Categories I and II shall have this evidence validated by a Category II or III person or, in the absence of such a person, by the candidate’s technical supervisor.

5.4.3 Candidates for Category III shall have this evidence validated by a Category III person or, in the absence of such a person, by the candidate’s technical supervisor.

5.4.4 The validation for all categories requires the signature of the validating person on the documentary evidence. The validating person should augment this validation process via oral assessment, accompanied task performance, report submission and review, procedure submission and review or a combination thereof, to increase the confidence of the validation.

6.1.1 For each Category, candidates shall be required to answer a fixed minimum number of multiple-choice questions in a specified time duration as indicated by Table 3.

6.1.2 Questions shall be of a practical nature yet test the candidate on concepts and principles required to conduct Optical Gas Imaging on components.

6.1.3 The examination for Category I shall consist of a Part A — General Theory and a Part B — Practical Application. The Part B examination shall cover quality data acquisition, the recognition, prevention and control of error sources and basic leak detection. This examination may include physical data acquisition tasks in addition to image interpretation.

6.1.4 The examination for Category II shall consist of a Part A — General Theory (50 %) and a Part B — Practical Application (50 %). The Part B shall cover detector types, sensor selection, image analysis image interpretation and quantification. This examination may include both physical data acquisition tasks in addition to image interpretation and analysis.

6.1.5 The examination for Category III shall consist of a Part A — General Theory (50 %) and a Part B — Practical Application (50 %). The Part B shall cover component operation (tanks, valves, separators, wells, compressors, controllers, flares), leak verification methods, leak quantification methods, inspection procedure development and program development. Part B may also include narrative and short answer questions. Some questions shall involve the interpretation of thermal images and/or videos. Simple mathematical calculations using a basic scientific calculator may be required. A summary of common formulae may be provided along with the basic examination questions.

6.1.6 Examination content shall be proportionate with the training syllabus contained in Annex A and assessing the test takers knowledge to do the required tasks indicated in Clause 4. The passing grade for each exam form shall be determined utilizing accepted psychometric methods such as the Angoff Method.

6.1.7 Certification bodies may, at their discretion, make accommodations for candidates with conditions that may require some form of compensation.

Table 3 — Minimum examination content

All examinations shall be conducted at examination sites approved by the certification body and according to the following requirements:

a) The examination shall be closed book, except for material provided by the certification body (e.g. a summary of common formulae). However, the examination for the highest category may, at the discretion of the certification body, be open book.

b) The candidates shall have access to simple drafting instruments and basic, non-programmable scientific calculators.

c) No examination related materials shall be retained by the candidate.

d) Any candidate who, during the examination, does not abide by the examination rules or who perpetrates, or is an accessory to, fraudulent conduct shall be excluded from further participation in that examination session (see also ISO 18436-1, Clause 7).

e) All examiners or invigilators of condition monitoring examinations shall sign a statement indicating that they understand and have observed the rules of examination conduct.

f) In cases where the examination is paper based, the following shall also apply:

I. At the start of the examination, the individual sealed envelopes, labelled with the candidates' names and containing the examination questions, shall be distributed to the candidates by the invigilator.

II. Upon instructions from the invigilator, the candidates shall open their envelopes and answer the questions.

III. At the completion of a written examination, the candidates shall place their examination papers into the envelopes provided, seal and sign them, and give them to the invigilator, who shall forward them directly to the certification body.

IV. Candidates shall be prohibited from answering questions in pencil or using correction fluid, except where test papers are to be scored by electronic means and shall be required to initial any corrections they may make on examination papers.

1. 
   (normative)
   Examination content and training syllabus