Document Architecture
Test method standards have a specific prescribed internal architecture, separate from a general product specification standard. The rules come from two aligned sources: Australia’s SG-006 (which governs Australian Standards) and the ISO/IEC Directives Part 2 (which governs ISO/IEC standards and which Australian adopted standards follow). Because Standards Australia is a member of ISO, these frameworks are closely harmonised.
The Two Contexts for a Test Method
A test method in a standard can appear in one of three ways:
- As a standalone standard: a dedicated test method document (e.g. AS 1012.9 Methods of testing concrete: compressive strength tests). A test method shall be prepared as a separate standard if it is likely to be referred to in a number of other standards.
- As a clause within a product standard: embedded in the technical content section of a product specification.
- As an appendix: attached to a standard when the test method applies only to that product.
If a test method is, or is likely to be, applicable to two or more types of product, a document shall be prepared on the method itself, and each document dealing with the specific product can then make normative reference to it.
The Internal Structure of a Test Method
Both SG-006 and the ISO/IEC Directives specify the same mandatory sequence of clauses inside a test method. The prescribed structure is: (a) principle; (b) reagents and materials; (c) apparatus; (d) preparation and preservation of test samples and test pieces; (e) procedure; (f) expression of results, including method of calculation and precision of the test method, and in ISO, the measurement uncertainty; (g) test report.
This is the canonical test method “architechture”. Here is what each clause must contain:
1. Principle: This clause explains what the test is measuring and why the physical, chemical or mechanical basis of the method. It is a factual, informative statement. It does not contain requirements (no “shall”), only a clear description of what phenomenon the test exploits. For example: “The test measures compressive force applied to a specimen until failure, expressed as force per unit area.”
2. Reagents and Materials: Lists all chemical reagents, reference materials, or consumables required. Only reagents of recognized analytical grade shall be used, and only distilled water or water of equivalent purity where applicable. Each reagent is listed individually, with its specification and grade. This clause uses “shall” where a specific grade is mandatory.
3. Apparatus: Lists all equipment, instruments, and measuring devices required to carry out the test. In a method of test, clauses that list apparatus, reagents and equipment may list each item without a heading. Each item is listed with its specification — tolerance, accuracy, calibration requirements. For example: “A compression testing machine capable of applying load at a rate of 20 ± 2 kN/s.”
If apparatus has to be built, blueprints or plans should be cited in the standard as adjunct material.
4. Preparation and Preservation of Test Samples and Test Pieces: This clause covers sampling and specimen preparation — how to take a representative sample from a batch, how to prepare it (cutting, conditioning, curing), and how to store or preserve it prior to testing. When a specific sampling method is necessary, this shall be clearly stated in the test method.
This is a critical clause because results are only valid if the specimen is representative and prepared consistently.
5. Procedure: The step-by-step instructions for conducting the test. This is the largest and most detailed clause, written as a numbered sequence of imperative instructions using “shall”. It covers:
- Setting up the apparatus
- Conditioning the specimen (temperature, humidity, duration)
- Applying the load, exposure, or stimulus
- The sequence of operations
- Recording observations
The document shall specify the sequence of testing if the sequence can influence the results. The procedure is written so that a competent technician with no prior knowledge of the test can reproduce it exactly and obtain the same result.
6. Expression of Results: This clause covers how raw test data is converted into a reported result. It includes:
- The calculation formula (with defined symbols)
- Rounding rules and significant figures
- Units of measurement
- How to handle multiple specimens (e.g. average, minimum, discard outliers)
- Precision the repeatability (same lab) and reproducibility (different labs) of the method
- In ISO standards specifically: measurement uncertainty, quantifying the range within which the true value is expected to lie
When it is technically necessary, each test method shall incorporate a statement as to its limit of accuracy. The chosen test method shall provide an unambiguous determination of whether the sample meets the specified requirement.
7. Test Report: The final mandatory clause specifies exactly what information the test report must contain. This clause shall require information to be given on at least the following aspects of the test: identification of the sample, the result(s), including a reference to the clause which explains how the results were calculated.
A typical test report clause requires:
- Identification of the product tested (type, batch, source)
- Reference to the standard and test method used
- Date of testing and laboratory identification
- Description of the specimen and how it was prepared
- Test conditions (temperature, humidity, loading rate)
- Individual and calculated results with units
- Any deviations from the standard procedure
- Signature of the responsible person
Additional Rules That Apply to Test Methods
Health and Safety Warnings: When health, safety or environmental warnings are necessary, these should be placed next to the relevant content in the test method. General warnings should be placed at the beginning of the test method.
Test Types: If appropriate, tests shall be identified as, for example, type tests, performance tests, sampling tests or routine tests. This distinguishes whether a test is for initial product approval, ongoing quality control, or batch acceptance.
One Method Per Characteristic: If more than one adequate test method exists for a characteristic, only one should in principle be specified. If, for any reason, more than one test method is to be specified, a referee test method may be identified in the document to resolve doubts or disputes.
Relationship to Requirements: Requirements, sampling and test methods are interrelated elements of product standardization and should be considered together, even though the different elements may appear in separate clauses in a document, or in separate documents. This is why a product standard will often say “tested in accordance with Clause X” or reference a separate test method standard — the requirement and the method of verifying it are always linked.