IEC 61672-3:2013

Overview

IEC 61672-3:2013 is an international standard published by the International Electrotechnical Commission (IEC) that specifies procedures for the periodic testing of sound level meters. This part of the IEC 61672 series focuses on ensuring that sound level meters, designed to meet the class 1 or class 2 specifications of IEC 61672-1 (second edition), consistently maintain their performance over time.

The primary goal of IEC 61672-3:2013 is to provide uniform and reliable testing methods across laboratories worldwide. It covers key tests and environmental conditions necessary to verify a sound level meter’s conformance to the required specifications during periodic assessments. This standard applies to integrating-averaging and time-weighting sound level meters, regardless of whether they have gone through pattern approval according to IEC 61672-2.

Key Topics

• Scope and Applicability
  IEC 61672-3 applies specifically to sound level meters claiming conformance to the second edition of IEC 61672-1 and covers only essential tests needed for periodic evaluation, making it a practical tool for routine quality assurance.

• Test Procedures and Requirements
  The standard details how to conduct tests on important aspects such as:

  • Time-weighting and frequency weighting performance
  • Acoustical sensitivity using sound calibrators
  • Level linearity across reference and extended level ranges
  • Toneburst response
  • Self-generated noise and overload indication
  • Long-term stability and high-level stability

• Conformance Criteria
  Conformance is achieved when measured deviations from design goals are within acceptance limits and the measurement uncertainties do not exceed permitted maxima, both evaluated with 95% coverage probability.

• Environmental Conditions and Equipment Setup
  Environmental parameters like temperature, humidity, and power supply are controlled during testing to ensure consistent and valid results. The standard also mandates submission of correct documentation, including an instruction manual and associated accessories.

• Documentation and Reporting
  Detailed test documentation and traceability to referenced standards such as IEC 60942 (sound calibrators), IEC 61094 series (microphones), and IEC 61672-1/2 are required, reinforcing transparency and reproducibility in periodic testing.

Uses and Applications

• Quality Assurance in Noise Measurement
  Organizations and calibration laboratories use IEC 61672-3 to verify the ongoing reliability of their sound level meters, ensuring that these instruments produce accurate and reliable noise measurements critical in environments such as urban noise monitoring, industrial safety, and occupational health.

• Regulatory Compliance
  Compliance with IEC 61672-3 supports conformance to local and international regulations that require periodic verification of noise measurement equipment, helping environmental and workplace safety agencies maintain standards.

• Instrument Maintenance Planning
  The standard guides service providers on recommended periodic checks, facilitating proactive maintenance schedules and minimizing unexpected instrument failures.

• Supporting Pattern Approval and Type Testing
  While IEC 61672-3 focuses on periodic testing, it complements the initial pattern approval tests defined in IEC 61672-2, allowing users to maintain meter performance throughout its lifecycle.

Related Standards

• IEC 61672-1: Electroacoustics – Sound Level Meters – Part 1: Specifications
  Defines the fundamental performance requirements for sound level meters.

• IEC 61672-2: Electroacoustics – Sound Level Meters – Part 2: Pattern Evaluation Tests
  Specifies pattern approval procedures validating new models of sound level meters.

• IEC 60942: Electroacoustics – Sound Calibrators
  Covers requirements for devices used to calibrate sound level meters during periodic tests.

• IEC 61094 series: Measurement Microphones
  Includes methods for calibration and frequency response determination of microphones, essential for accurate sound measurement.

• IEC 62585: Electroacoustics – Corrections for Free-Field Response
  Provides methods for correcting sound level meter responses to simulate free-field acoustic conditions.

• ISO/IEC Guides 98-3 and 99: Uncertainty of Measurement and Metrological Vocabulary
  Offer guidance on expressing measurement uncertainty and defining metrological concepts, underpinning the conformance criteria in IEC 61672-3.

IEC 61672-3:2013 is essential for professionals involved in electroacoustic measurements, providing a rigorous and standardized framework for periodic testing of sound level meters. Its adoption helps maintain measurement integrity in noise monitoring, safety evaluation, and compliance testing worldwide.