Approved Method: IES Guide for Determination of Average Luminance (Calculated) for Indoor Luminaires

IES Guide for Determination of Average Luminance (Calculated) for Indoor Luminaires

$60.00

Member Price: $40.00

ANSI/IES LM-37-20
Document Type: Lighting Measurement and Testing (LM)

Available as a downloadable secure PDF only.

To stay current with all IES standards, we recommend subscribing to the The Lighting Library as an Individual or through your company as a Sustaining Member.

In stock

SKU: ANSI/IES LM-37-20 Category: Tag:

Product Description

Approved American National StandardThis document’s methods of calculating average luminance cover various open-bottom apertures as well as flat- and drop-lensed units, including those with multiple openings in the light emitting area. The candela values of interest are obtained by means of IES techniques for relative or absolute photometry, and are not obtained from field measurements in application. This calculation is based solely on the candela values obtained by goniometric measurement of the luminaire and the luminous projected area. All light sources for which there are current standards for luminaire photometry are covered by this document. These include incandescent, fluorescent, high intensity discharge (HID), low pressure sodium, and LED sources.

Page count: 17 pages
Publisher: Illuminating Engineering Society (2020)
SKU: ANSI/IES LM-37-20
ISBN-13: 978-0-87995-198-6

Chapters:

  • 1.0 Introduction and Scope
    2.0 Normative References
    3.0 Definitions and Nomenclature
    4.0 General Method of Calculation of Average Luminance (Calculated)

Citation Format:
Illuminating Engineering Society. ANSI/IES LM-37-20, Approved Method: IES Guide for Determination of Average Luminance (Calculated) for Indoor Luminaires. New York: IES; 2020.

CONTENTS

  • 1.0 Introduction and Scope
  • 1.1 Introduction
  • 1.2 Scope
  • 2.0 Normative References
  • 3.0 Nomenclature and Definitions
  • 3.1 AB
  • 3.2 ABP
  • 3.3 angle θ (vertical viewing angle)
  • 3.4 angle ψ (horizontal viewing angle)
  • 3.5 AS
  • 3.6 ASP
  • 3.7 average luminance (calculated)
  • 3.8 D
  • 3.9 H
  • 3.10 L, W
  • 3.11 total projected luminous area (at viewing angle θ)
  • 4.0 General Method of Calculation of Average Luminance (Calculated)
  • 4.1 Circular Luminaire Openings (Open Bottom or Flat Lens)
  • 4.2 Circular Luminaire Openings with Drop Lenses
  • 4.3 Square or Rectangular Luminaire Openings (Open Bottom or Flat Lens)
  • 4.4 Square or Rectangular Luminaire Openings with Drop Lenses
  • 4.5 Irregularly Shaped or Polygonal Openings for Luminaires
  • 4.6 Projected Area Formula for Luminous Opening Types Defined in LM-63
    4.6.1 Point
    4.6.2 Rectangular
    4.6.3 Rectangular with Luminous Sides
    4.6.4 Circular
    4.6.5 Ellipse
    4.6.6 Vertical Cylinder
    4.6.7 Sphere
    4.6.8 Horizontal Cylinder along Photometric Horizontal
    4.6.9 Horizontal Cylinder Perpendicular to Photometric Horizontal
    4.6.10 Vertical Circle Facing Photometric Horizontal
    4.6.11 Vertical Ellipse Facing Photometric Horizontal
  • 4.7 Surfaces with Multiple Light Emitting Openings
  • Annex A – Representative Area Formulas Reference (not all-inclusive)
  • A.1 Circular Luminaire Opening (Open Bottom or Flat Lens)
  • A.2 Circular Luminaire Openings with Drop Lenses (Truncated Cone)
  • A.3 Square or Rectangular Luminaire Openings (Open Bottom or Flat Lens)
  • A.4 Square or Rectangular Luminaire Openings with Drop Lenses
  • A.5 Spherical Lens
  • Informative References