ISO 17123-5:2018

Overview

ISO 17123-5:2018 - "Optics and optical instruments - Field procedures for testing geodetic and surveying instruments - Part 5: Total stations" defines practical, in‑situ field procedures for evaluating the precision (repeatability) of coordinate measurements made by total stations and ancillary equipment in building and surveying tasks. Published as the third edition in 2018, the standard focuses on simple, deployable tests that require no special ancillary equipment and are designed to minimize atmospheric influences. These procedures are intended as field verifications of suitability for immediate tasks, not as comprehensive acceptance or full performance evaluations.

Key topics and technical requirements

• Scope and intent: Field verification of coordinate-measurement repeatability for total stations; suitability checks for immediate surveying tasks.
• Two procedures provided:
  • Procedure 1 - Simplified test procedure: quick field checks for common tasks (configuration, measurement, basic calculation).
  • Procedure 2 - Full test procedure: detailed field layout, measurement protocol, calculations and statistical tests for a more complete uncertainty assessment.
• Coordinate components: Tests and calculations cover x, y (horizontal) and z (height) coordinates, with explicit calculation and evaluation steps.
• Statistical evaluation: Includes experimental standard deviation, statistical tests (e.g., chi-squared related methods) and combined uncertainty evaluation (Type A and Type B) following GUM principles.
• Instrument and environmental requirements:
  • Instrument and ancillary equipment must be in known acceptable adjustment per manufacturer guidance.
  • All coordinates measured on the same day; instrument carefully levelled; correct prism zero-point correction applied.
  • Measurement of meteorological data (temperature, pressure, humidity, wind, cloud cover) to derive atmospheric corrections for distances.
• Examples and guidance: Informative annexes provide worked examples for simplified and full procedures and uncertainty budgets.

Practical applications

• Rapid on-site verification of total station suitability before construction layout, as-built surveys, monitoring or control surveys.
• Routine quality assurance checks by survey crews to confirm instrument repeatability under actual field conditions.
• Input for uncertainty budgets in project deliverables where a quantified measurement uncertainty is required.
• Support for accreditation or contractual compliance where field verification is specified.

Who should use this standard

• Surveyors and field technicians operating total stations
• Geodetic engineers and instrumentation teams
• Construction and building measurement professionals
• Calibration labs, QA managers and procurement specialists evaluating instrument readiness

Related standards (normative references)

• ISO 17123-1 (Theory)
• ISO 17123-3 (Theodolites)
• ISO 17123-4 (EDM to reflectors)
• ISO/IEC Guide 98-3 (GUM) - Guide to the expression of uncertainty in measurement
• ISO 3534‑1, ISO 9849 and building measurement standards cited within ISO 17123-5

Keywords: ISO 17123-5:2018, total stations, field procedures, measurement uncertainty, repeatability, combined uncertainty, geodetic instruments, surveying instruments, in situ verification.