IEC TR 61341-2010 PDF

Full title and description

Method of measurement of centre beam intensity and beam angle(s) of reflector lamps — IEC/TR 61341:2010 (Second edition). This technical report specifies measurement procedures and reporting conventions for centre beam intensity and beam angles of reflector lamps used for general lighting, including incandescent, halogen, gas-discharge and LED-based reflector lamps.

Abstract

IEC/TR 61341:2010 defines how to measure and specify the centre beam intensity (axial intensity) and the associated beam angle(s) of reflector lamps. The report updates the earlier 1994 edition to cover LED-based reflector lamps and adds measurement conditions and illustrative figures to clarify axis definitions and intensity relationships. It also provides guidance to report full luminous intensity distribution where the centre beam intensity is very low (for example, "butterfly" distributions).

General information

• Status: Published — Technical Report (IEC).
• Publication date: 18 February 2010.
• Publisher: International Electrotechnical Commission (IEC).
• ICS / categories: 29.140.20 (Electric lamps and lighting).
• Edition / version: 2nd edition (2010).
• Number of pages: 20 pages.

Scope

The report applies to reflector lamps for general lighting purposes — including incandescent, tungsten halogen, gas-discharge and LED reflector lamps — and specifies methods for determining centre beam intensity and one or more beam angles. It does not apply to lamps for special purposes such as projection lamps. Measurement conditions and reporting conventions have been broadened relative to the 1994 edition to take account of reflector-equipped LED lamps; the report also instructs when to report the full luminous intensity distribution instead of a single centre-beam number.

Key topics and requirements

• Definitions of centre beam (axial) intensity and beam angle(s) for reflector lamps.
• Detailed measurement procedure for centre beam intensity using photometric equipment and specified geometry.
• Methods to determine beam angles associated with specified intensity fractions (e.g., half-intensity beam angle conventions).
• Special measurement conditions and guidance addressing LED-based reflector lamps (including handling of non-axial and asymmetric distributions).
• Requirement to report luminous intensity distribution when centre beam intensity is not representative (e.g., "butterfly" distributions).
• Illustrative figures showing relationships between axes and intensities to improve clarity of reporting and interpretation.

Typical use and users

Used by lamp and lighting manufacturers, photometric and test laboratories, certification and conformity assessment bodies, standards committees, and lighting designers who need consistent, comparable photometric data for reflector lamps. The technical report has been adopted into relevant regional/national publications (for example as EN 61341 in European adoption processes).

Related standards

Closely related to other IEC and EN documents on lamp and photometric measurement (work by IEC TC 34 / SC 34A and corresponding CIE and regional measurement guidance). It has been used as the basis for EN adoption (EN 61341:2011 / national adoptions) and should be considered alongside standards for luminaire and lamp photometry when performing complete lighting assessments.

Keywords

centre beam intensity, axial intensity, beam angle, reflector lamps, LED reflector lamps, photometry, luminous intensity distribution, IEC TR 61341

FAQ

Q: What is this standard?

A: IEC/TR 61341:2010 is a Technical Report from the IEC that specifies methods for measuring and reporting the centre beam intensity and beam angle(s) of reflector lamps.

Q: What does it cover?

A: It covers measurement procedures, measurement conditions (including considerations for LED reflector lamps), definitions of beam angles and conventions for reporting. It excludes lamps for special purposes such as projection lamps and recommends reporting full luminous intensity distribution when a single centre-beam value is not representative.

Q: Who typically uses it?

A: Lamp manufacturers, third‑party test laboratories, certification bodies, lighting designers and standards committees use it to ensure consistent photometric data for reflector lamps.

Q: Is it current or superseded?

A: IEC/TR 61341:2010 is the second edition (published 18 February 2010) and replaced the 1994 edition; users should check national/regional catalogs for any later amendments or related normative documents.

Q: Is it part of a series?

A: It is a Technical Report produced under IEC TC 34 / SC 34A (electric light sources). It is not a multi‑part normative series but is related to other IEC/EN documents on lamp and photometric measurement and regional adoptions (for example EN 61341:2011).

Q: What are the key keywords?

A: Centre beam intensity, beam angle, reflector lamp, LED reflector, photometric measurement, luminous intensity distribution.