ASTM E94: Standard Guide for Radiographic Examination
Comprehensive guide for industrial radiography including X-ray and gamma ray methods. ASTM E94 covers equipment, procedures, film quality, exposure parameters, and interpretation. It is the primary US standard for industrial radiography.
ASTM International is a consensus body that publishes test methods and practices used inside other codes; ASTM E-series documents are the most widely cited NDT references in North America.
ASTM standards become enforceable when invoked by a contract, by another code such as ASME Section V, or by a regulator citing them as the controlling test method.
ASTM E94 is invoked when the scope of work matches its title — standard guide for radiographic examination — and when the contract or regulatory regime cites it as the controlling document. On petroleum and petrochemical equipment, ASTM E94 usually feeds into a written mechanical-integrity program: inspection intervals, examination methods, and acceptance criteria are all traced back to a clause number in the document. Aerospace work treats the standard as a floor rather than a ceiling — most prime contractors layer their own internal procedures on top, with tighter acceptance criteria than the published code. In fabrication shops the standard is reproduced inside the written procedure book and referenced from every inspection report so that the auditor's paper trail leads back to the same paragraph the inspector worked from.
Methods covered
Industries
- Oil & Gas
- Manufacturing
- Construction
- Aerospace
- Personnel qualification: examinations under ASTM E94 must be performed by inspectors qualified and certified to a recognised scheme (typically ASNT SNT-TC-1A, CP-189, or ISO 9712 depending on jurisdiction), with documented training hours, vision tests, and a controlling written practice.
- Written procedure: every examination requires a written, controlled procedure that names the method, equipment, calibration steps, scanning pattern, and acceptance criteria — and is qualified before first use.
- Image-quality verification: every radiograph or digital exposure carries a penetrameter / IQI of the type and thickness specified by the standard; the IQI must be visible and at the required sensitivity for the radiograph to be acceptable.
- Radiation safety: source handling, exclusion zones, dosimetry, and source recordkeeping must follow the licensing authority's rules in addition to the inspection standard itself.
- Acceptance criteria: indications are evaluated against the standard's tabulated limits (length, depth, alignment, frequency); any indication exceeding the criteria is recorded, dispositioned, and either repaired or evaluated for fitness-for-service.
- Documentation: examination reports must include enough information for a third party to reproduce the inspection — equipment serial numbers, calibration records, inspector ID, sketches of indications, and the controlling procedure revision.
- Latest Edition
- ASTM E94/E94M-17 (2023)
- First Published
- 1947
- Scope
- Standard guide for radiographic examination using industrial X-ray and gamma-ray sources; broad tutorial covering film and digital.
- Acceptance Criteria
- None — references E390/E1742 (film handling) and customer/code acceptance.
- Calibration / Qualification
- References ASTM E747 (wire IQI) and E1025 (plaque IQI) for image quality verification.
Key Clauses Inspectors Cite
- Sec. 5 — Personnel and equipment
- Sec. 8 — Selecting radiographic technique
- Sec. 9 — Geometric principles
- Sec. 10 — Image quality and IQI
Companion / Parent Standards
ASTM E1742 (film processing) · ASTM E1032 (RT of weldments) · ASTM E747 (wire IQI) · ASTM E1025 (plaque IQI) · ASME Section V Article 2
Sample Contract Language
“RT technique shall comply with ASTM E94, with image quality per ASTM E1025 essential hole 2T.”
ASTM standards are reviewed on a five-year cycle and either reaffirmed, revised, or withdrawn. Revisions to ASTM E94 are generally evolutionary rather than revolutionary — clarifying language, adding new technique variants, or aligning with parallel ISO documents. The standard's designation includes the year of last revision (e.g. E709-21), and contracts that name a specific year freeze the inspection requirements to that revision.
A typical refinery turnaround applies ASTM E94 to the inspection scope for high-temperature piping and pressure vessels: corrosion-monitoring locations are read with UT thickness gauges, girth welds on repaired sections are radiographed or PAUT-scanned, and any indication outside the standard's acceptance table is dispositioned through API 579 fitness-for-service before the unit restarts.
What does ASTM E94 cover?
ASTM E94 (Standard Guide for Radiographic Examination) is published by ASTM International. Comprehensive guide for industrial radiography including X-ray and gamma ray methods.
Is ASTM E94 mandatory or voluntary?
ASTM E94 is a consensus standard. It becomes mandatory when invoked by a contract, by another code that cites it (for example ASME Section V calling out an ASTM practice), or by a regulator that has adopted it into law in a specific jurisdiction.
Who is qualified to perform inspections under ASTM E94?
Inspections under ASTM E94 must be performed by personnel qualified and certified to a recognised NDT certification scheme — most commonly ASNT SNT-TC-1A or CP-189 in the United States, ISO 9712 in much of the rest of the world, and NAS 410 for aerospace work. The written practice that controls qualification must be in place before any examination is started.
Which other standards are commonly cited alongside ASTM E94?
ASTM E94 is most often cited together with the parent code that brings it into the contract — typically ASME Section V or VIII for U.S. pressure equipment, AWS D1.1 for structural welding, API 510/570/653 for in-service petroleum equipment, or the matching EN/ISO standard for European and international work.
Standard Code
ASTM E94
Organization
ASTM International
Methods Covered
1 method(s)
Industries
4 sector(s)
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