CIE 198-2011 PDF

Full title and description

CIE 198:2011 — Determination of Measurement Uncertainties in Photometry. A CIE technical report that provides recommendations and a worked procedure for evaluating and reporting measurement uncertainties associated with photometric quantities (illuminance, luminance and other derived photometric values).

Abstract

This technical report summarises the fundamental definitions and procedures for estimating standard, combined and expanded uncertainties for photometric measurements, following the principles of the internationally recognised Guide to the Expression of Uncertainty in Measurements (GUM) and its supplements. It explains how to construct a measurement model, build uncertainty budgets for input quantities, account for correlations (addressed further in later supplements) and present final expanded uncertainty for reported photometric results.

General information

• Status: Active / current (technical report with subsequent supplements).
• Publication date: 2011.
• Publisher: International Commission on Illumination (CIE).
• ICS / categories: 17.180 (Optics and optical measurements / photometry).
• Edition / version: CIE Technical Report 198:2011 (first issued 2011); supplemented by CIE 198-SP1 (2011, multi-part) and CIE 198-SP2 (2018).
• Number of pages: 30 (main report; supplements published separately).

Scope

The report provides recommendations for the determination of measurement uncertainties associated with selected photometric quantities. It covers the steps from initial measurement procedures and calibration through formation of a measurement model and uncertainty budget, to the presentation of final values with associated expanded uncertainties. Supplements provide extensive worked examples and modules for common photometric measurement tasks, and a later supplement addresses spectral measurements and correlations.

Key topics and requirements

• Definitions and concepts for standard, combined and expanded uncertainty consistent with the GUM framework.
• Guidance on building measurement models (measurement equations) for photometric quantities.
• Methods for estimating uncertainty components from Type A (statistical) and Type B (other information) sources.
• Procedures for combining uncertainty contributions into an overall uncertainty budget and for reporting expanded uncertainty.
• Use of supplementary modules and worked examples (CIE 198‑SP1 series) to apply the general method to particular measurement configurations.
• Treatment of spectral measurements and correlations between spectral values (covered in CIE 198‑SP2:2018).

Typical use and users

Intended for national metrology institutes, calibration and testing laboratories, manufacturers of photometric instruments (photometers, spectroradiometers, luminance/illuminance meters), lighting designers and researchers who must quantify and report measurement uncertainty for photometric determinations. It is also used by standards developers and conformity assessment bodies when defining measurement and reporting requirements in lighting and optical measurement standards.

Related standards

Closely related documents include the CIE 198-SP1 supplements (modules and worked examples, 2011 multi-part), CIE 198‑SP2:2018 (spectral measurements and derivative quantities), ISO/CIE 19476 (performance of illuminance and luminance meters, which references CIE 198 for uncertainty treatment), CIE 202:2011 (spectral responsivity measurement), and the GUM (ISO/IEC Guide 98-3 and supplements) used as the uncertainty framework.

Keywords

photometry; measurement uncertainty; uncertainty budget; GUM; illuminance; luminance; spectral measurement; calibration; CIE technical report.

FAQ

Q: What is this standard?

A: CIE 198:2011 is a CIE technical report giving recommended procedures to determine and report measurement uncertainties for photometric quantities.

Q: What does it cover?

A: It covers the theoretical basis and practical steps for evaluating Type A and Type B uncertainty components, assembling an uncertainty budget, combining contributions and presenting expanded uncertainty for photometric results; worked examples and modules are provided in supplements.

Q: Who typically uses it?

A: Metrology and calibration laboratories, instrument manufacturers, lighting test laboratories, researchers and standards writers—anyone who must quantify and report the uncertainty of photometric measurements.

Q: Is it current or superseded?

A: The 2011 report remains current as the foundational CIE guidance for photometric uncertainty; it has been supplemented (CIE 198‑SP1 series in 2011 and CIE 198‑SP2 in 2018) rather than outright superseded. Users should consult the supplements for worked examples and spectral-correlation guidance.

Q: Is it part of a series?

A: Yes — CIE Technical Report 198 is the main report with a set of supplements (CIE 198‑SP1 parts and CIE 198‑SP2) that provide modules, detailed examples and extensions for specific measurement types.

Q: What are the key keywords?

A: Photometry, uncertainty, uncertainty budget, GUM, illuminance, luminance, spectral measurements, calibration.