Metrology and Measurement Standards: September 2025 Monthly Overview

Looking back at September 2025, the Metrology and Measurement: Physical Phenomena sector experienced a significant consolidation and modernization of standards, marking a pivotal period for practitioners focusing on radiation measurement, acoustic emissions, and calibration methodologies. Five major standards were released, including ground-breaking updates in radiological testing, railway vehicle noise measurement, and calibration protocols for beta-particle dosemeters. For industry professionals, compliance officers, engineers, and researchers, this monthly overview provides critical insights into evolving requirements, industry direction, and compliance considerations—a valuable resource to stay current and competitive in a rapidly advancing technical field.

Monthly Overview: September 2025

During September 2025, the Metrology and Measurement: Physical Phenomena sector saw the publication of five robust and detailed standards. These publications featured:

• A strong emphasis on radiation measurement and calibration, particularly via the complete update of the EN ISO 6980 series.
• Renewed attention to noise emission metrics for railbound vehicles, reflecting environmental and regulatory shifts.
• The introduction and harmonization of test protocols for alpha and beta radionuclides across applications ranging from environmental monitoring to nuclear safety and transport.

Compared to previous months, September’s output demonstrated an uptick in standards focusing on quantitative measurement—reinforcing global trends toward harmonization, interlaboratory comparability, and safer, more sustainable infrastructure. This strengthened platform of guidance addresses increased regulatory scrutiny, cross-border compliance demands, and technological advances in instrumentation.

With a blend of new methodologies and refined revisions, these standards reinforce the importance of accuracy, reproducibility, and traceability in measurements that underpin decision-making in safety, public health, energy, and transportation.

Standards Published This Month

EN ISO 23548:2025 - Measurement of radioactivity - Alpha emitting radionuclides - Generic test method using alpha spectrometry

Measurement of radioactivity - Alpha emitting radionuclides - Generic test method using alpha spectrometry (ISO 23548:2024)

EN ISO 23548:2025 established a rigorous, generic methodology for quantifying alpha-emitting radionuclides in a broad array of sample types—including environmental (soil, water, bio-indicators), construction materials, foodstuffs, and even human biological fluids. The standard provides detailed requirements for sample pre-treatment, radiochemical separation, and thin-source preparation to ensure that the subsequent alpha spectrometric measurements yield accurate, traceable results even at extremely low detection levels—one to two orders of magnitude below typical background radiation.

Applicable to organizations performing environmental studies, radiological protection, nuclear site monitoring, or food safety investigations, the standard also offers annexes supporting best practices in sample handling, calibration, uncertainty evaluation, and reporting. By specifying reference activities for isotopes such as 210Po, 226Ra, 238U, 241Am, and various plutonium and thorium isotopes, EN ISO 23548:2025 helps unify measurement outcomes across laboratories and test scenarios.

Key highlights:

• Covers generic procedures for all sample matrices (soil, water, food, biological, airborne).
• Enables detection and quantification of ultra-low-level alpha emitters, supporting environmental safety.
• Harmonizes international measurement practices, aiding interlaboratory comparability.

Access the full standard:View EN ISO 23548:2025 on iTeh Standards

EN ISO 3095:2025 - Railway applications - Acoustics - Measurement of noise emitted by railbound vehicles

Railway applications - Acoustics - Measurement of noise emitted by railbound vehicles (ISO 3095:2025)

EN ISO 3095:2025 replaces earlier versions with updated procedures and stricter definitions for measuring and reporting exterior noise emissions from rail vehicles. This standard is critical for railway manufacturers, rolling stock operators, regulatory agencies, and acoustic consultants needing to demonstrate compliance with environmental noise restrictions and improve passenger or residential quality of life.

The standard articulates reproducible test methods for various operating scenarios (constant speed, acceleration, stationary), stipulating requirements for instrumentation, environmental conditions, data processing, and test reporting. It excludes infrastructure-derived noises (such as those from tracks, crossings, and bridges) and warning signals, keeping the focus on the vehicle as the sound source. This precision delivers more accurate source attribution and supports type approval testing, inter-vehicle comparisons, and data collection for predictive acoustic modeling.

Key highlights:

• Standardizes exterior noise measurement for all rail vehicles under various conditions.
• Supports comparative assessments and regulatory compliance for acoustic emissions.
• Incorporates the latest guidance for urban rail vehicles in dedicated annexes.

Access the full standard:View EN ISO 3095:2025 on iTeh Standards

EN ISO 6980-1:2025 - Nuclear energy - Reference beta-particle radiation - Part 1: Methods of production

Nuclear energy - Reference beta-particle radiation - Part 1: Methods of production (ISO 6980-1:2023)

EN ISO 6980-1:2025 inaugurates a comprehensive revision of reference beta-particle radiation field production for calibration of personal and area dosemeters. It sets forth detailed specifications for the types of radioactive sources (such as 90Sr/90Y, 85Kr, 204Tl, and 147Pm) suitable for producing standard beta fields, and distinguishes between two principal series: with (Series 1) and without (Series 2) beam-flattening filters. This strategy enables users to select radiation fields tailored to their calibration needs, energy ranges, and required uniformity of dose rate.

The standard addresses essential criteria including energy distribution, photon contamination, spatial dose uniformity, and stability over time. It is indispensable for calibration laboratories, nuclear power facilities, research centers, and instrument manufacturers who are responsible for ensuring the traceability and reliability of beta-radiation instruments used in occupational and environmental dosimetry.

Key highlights:

• Defines requirements for reference beta-particle radiation fields across two source series.
• Supports energy ranges from 0.22 MeV to 3.6 MeV and dose rates up to 10 Sv·h⁻¹.
• Forms the foundational step for subsequent calibration and dosimetry procedures in the series.

Access the full standard:View EN ISO 6980-1:2025 on iTeh Standards

EN ISO 6980-2:2025 - Nuclear energy - Reference beta-particle radiation - Part 2: Calibration fundamentals related to basic quantities characterizing the radiation field

Nuclear energy - Reference beta-particle radiation - Part 2: Calibration fundamentals related to basic quantities characterizing the radiation field (ISO 6980-2:2023, including corrected version 2024-03)

Building on Part 1, EN ISO 6980-2:2025 details methods for measuring the absorbed-dose rate in tissue-equivalent phantoms subjected to the reference beta-particle fields described earlier. This part is particularly targeted at organizations setting up or maintaining primary dosimetry calibration capabilities for beta radiation, such as national metrology institutes and accredited calibration laboratories.

The standard describes proper use of extrapolation chambers as primary standards, outlines uncertainty analysis in dosimetry, and provides guidance on alternative measurement systems and test geometries. Its correct application ensures traceability and comparability in radiation protection dosimetry across diverse institutions and jurisdictions.

Key highlights:

• Specifies absorbed dose measurement techniques in tissue-equivalent phantoms.
• Recommends tools and methodologies to quantify uncertainty and maintain calibration accuracy.
• Essential for users establishing or verifying primary beta-particle dosimetry.

Access the full standard:View EN ISO 6980-2:2025 on iTeh Standards

EN ISO 6980-3:2025 - Nuclear energy - Reference beta-particle radiation - Part 3: Calibration of area and personal dosemeters and the determination of their response as a function of beta radiation energy and angle of incidence

Nuclear energy - Reference beta-particle radiation - Part 3: Calibration of area and personal dosemeters and the determination of their response as a function of beta radiation energy and angle of incidence (ISO 6980-3:2023)

Finalizing the series, EN ISO 6980-3:2025 provides comprehensive procedures for calibrating area and personal dosemeters using the reference beta-particle fields. The standard requires that instruments be tested across a range of beta energies and angles of incidence, mirroring conditions encountered in practical radiation protection scenarios. In addition to calibration protocols, the document guides users in the proper preparation of phantoms, selection of conversion coefficients, calculation of response factors, and reporting to ISO/IEC 17025 standards.

This standard is critical for organizations calibrating personnel dosimeters for occupational safety, radiation protection, and health physics. Its rigorous approach ensures that dosemeters accurately reflect true personal dose under varying field conditions and support regulatory compliance.

Key highlights:

• Codifies procedures for calibrating both area and personal dosemeters to reference beta fields.
• Ensures that dosimeter response is characterized over energy and angle ranges relevant to real-world exposures.
• Promotes comparability and traceability in personal and area dosimetry across laboratories.

Access the full standard:View EN ISO 6980-3:2025 on iTeh Standards

Common Themes and Industry Trends

A retrospective analysis of September 2025’s standards reveals several significant patterns:

• Strengthened Regulatory Alignment: The simultaneous release of all three parts of the EN ISO 6980 series supports harmonization in dosimetry practices, crucial as regulatory frameworks become more rigorous and globalized.
• Environmental and Health Protection: The focus on ultra-sensitive radiation measurement and acoustic emissions demonstrates an industry shift towards mitigating environmental and occupational hazards.
• Integrated Measurement Strategies: The sectors addressed—ranging from transport acoustics to alpha and beta particle quantification—reflect a growing expectation for holistic, cross-disciplinary measurement approaches that link industrial activity, public health, and environmental stewardship.
• Traceability and Uncertainty: Emphasis on detailed uncertainty analysis, calibration traceability, and international comparability acknowledges the need for defensibility in regulatory reporting, litigation, and cross-border data exchanges.

Radiation measurement and acoustic standards are converging around shared best practices that prioritize technology-neutral protocols, interoperability, and a lifecycle approach to measurement integrity—from sample collection or instrument calibration through to result reporting and compliance documentation.

Compliance and Implementation Considerations

For organizations affected by these standards, implementation should be approached with careful planning:

• Gap Analysis: Review current test procedures, equipment calibration intervals, and uncertainty budgets against new or revised requirements—especially if prior compliance was based on superseded EN/ISO standards.
• Training and Competence: Ensure that technical staff receive updated training on new protocols for sample handling, spectrometry, chamber use, or acoustic instrumentation, as detailed in the standards.
• Documentation and Record-Keeping: Align reporting formats to reflect ISO/IEC 17025 or other applicable criteria, particularly for calibration of dosemeters, uncertainty statements, and traceability chains.
• Timelines: While many standards allow transition periods, organizations are advised to prioritize changes impacting regulatory compliance or third-party certification first. The harmonized approach to calibration may also accelerate conformance deadlines in international contracts or tenders.
• Resource Allocation: Budget for any equipment upgrades (e.g., newer extrapolation chambers, spectrometers, or data acquisition systems) required to achieve the prescribed detection limits, energy ranges, or noise floor metrics.
• External Resources: Reference manufacturer guidance, professional society materials, and resources available through standards platforms such as iTeh Standards for further support.

Conclusion: Key Takeaways from September 2025

September 2025 marked a milestone in the Metrology and Measurement: Physical Phenomena sector through:

• The completion of the EN ISO 6980 trilogy, establishing a robust reference for beta-particle measurement across production, calibration, and application.
• The advancement of protocols for alpha spectrometry (EN ISO 23548:2025) and acoustic testing (EN ISO 3095:2025), supporting better environmental monitoring and infrastructure planning.
• Cross-cutting improvements in measurement traceability, interlaboratory comparability, and test accuracy.

For professionals responsible for radiation safety, environmental monitoring, transport compliance, and metrological integrity, reviewing and integrating these standards into organizational practice will ensure continued leadership in operational excellence and regulatory adherence. Staying current with such publications via iTeh Standards not only facilitates compliance but also promotes safer workplaces, robust public health protections, and internationally recognized best practices.

Explore the full portfolio of Metrology and Measurement: Physical Phenomena standards and stay ahead of the curve with iTeh Standards.