ISO 17123-6:2025

Overview

ISO 17123-6:2025 - "Optics and optical instruments - Field procedures for testing geodetic and surveying instruments - Part 6: Rotating lasers" defines practical, in‑situ field procedures for assessing the precision and measurement uncertainty of rotating lasers used in levelling and surveying tasks. The standard focuses on repeatability, between‑day reproducibility, and a structured evaluation of error sources to produce a combined standard uncertainty in accordance with ISO/IEC Guide 98-3 (GUM). It is intended as a field verification of an instrument’s suitability for immediate tasks rather than a full acceptance test.

Key topics and requirements

• Two selectable procedures:
  • Procedure 1 - Simplified test: a limited-measurement check for quick verification on construction and site levelling tasks.
  • Procedure 2 - Full test: a comprehensive field verification including statistical tests and uncertainty budgeting.
• Emphasis on in situ testing without special ancillary equipment and on configuring tests to minimize atmospheric influences (e.g., temperature gradients, wind).
• Differentiation between precision measures: repeatability (Type A) and reproducibility (between-day).
• Guidance for setting up test geometry: test field (simplified) and test line (full), measurement sequences and computation of residuals.
• Statistical assessments referenced: t-distribution, Fisher (F) distribution, chi‑squared (χ²) tests to support decision criteria and significance levels.
• Identification and evaluation of influence quantities and construction of an uncertainty budget (Type A and Type B contributions).
• Informative annexes providing worked examples for the simplified and full procedures and for calculating an uncertainty budget.

Practical applications

• Verifying rotating-laser precision for building construction, site levelling, and general surveying tasks.
• Providing a documented basis for estimating measurement uncertainty when reporting levelling results.
• Supporting operational decisions on whether a specific rotating laser is fit for a particular project environment and conditions.
• Useful for routine site checks prior to critical levelling activities where documented measurement quality is required.

Who should use this standard

• Surveyors and geodetic technicians performing levelling on construction and infrastructure projects.
• Quality managers and site engineers needing documented field verification of measuring equipment.
• Calibration and metrology personnel who integrate field verification data into broader uncertainty assessments.
• Instrument manufacturers and technical support teams preparing user guidance that aligns with international practice.

Related standards

• ISO 17123-1 (Theory)
• ISO 17123-2 (Levels)
• ISO/IEC Guide 98-3 (GUM: uncertainty of measurement)
• ISO 3534-1, ISO 4463-1, ISO 7077, ISO 7078, ISO 9849

Keywords: ISO 17123-6:2025, rotating lasers, field procedures, measurement uncertainty, repeatability, levelling, geodetic instruments, in situ testing.