ISO/PAS 13473-6:2021

Overview

ISO/PAS 13473-6:2021 - Characterization of pavement texture by use of surface profiles, Part 6 - provides an internationally accepted procedure for verification of laser profilometers used in pavement texture measurement. It defines methods to check whether contactless laser systems (point or line triangulation profilometers) perform satisfactorily for pavement texture tasks, helps detect performance faults, and explains limitations and trade-offs of laser-based profilometer systems. This document complements other parts of the ISO 13473 series (notably ISO 13473-1) and includes an Annex A with reference program code, digital profiles and reference MPD values to exclude software interpretation errors.

Key topics and requirements

The standard identifies key design and performance parameters and gives test methods and instruments to evaluate them. Major technical topics include:

• Calibration (scale) accuracy - methods to verify the vertical scale and calibration procedures.
• Laser power and spot size - tests to assess beam strength and resolution.
• Nonlinearity and measurement range/standoff - checks for linear response across the sensor range and definitions of standoff and range.
• Background noise and spike content - evaluation of signal noise (RMS/white noise) and transient spikes.
• Horizontal position (distance) accuracy - tests for mobile (continuous) and stationary (spot) systems.
• Sensitivity to abrupt surface reflectivity changes and effect of ambient light - procedures to assess robustness on varying pavement colours and lighting.
• Dropout rate and dropout detection validation - methods to detect missing data points and verify indicators.
• Synchronization between invalid profile segments and dropout flags.
• Ambient testing conditions, frequency of testing, and test reporting - guidance on test environment, how often verifications should be run, and required report content.

The standard also warns about laser eye safety and explicitly states it is not intended as a formal qualification or approval scheme for devices.

Applications and users

ISO/PAS 13473-6:2021 is practical for:

• Pavement engineers and asset managers performing texture surveys.
• Research labs studying tyre/road noise, skid resistance, rolling resistance, splash and spray.
• Equipment manufacturers and calibration/QA laboratories verifying profilometer performance.
• Procurement, field technicians and quality control teams resolving inter-device measurement discrepancies.

Using this standard helps ensure consistent, traceable pavement texture data such as MPD (Mean Profile Depth) and reduces unacceptable differences between laser profilometers.

Related standards

• ISO 13473-1 (Determination of Mean Profile Depth) - normative reference.
• Other parts of the ISO 13473 series - for complementary specifications on texture measurement.