Technical Memorandum: An Optional Method for Adjusting the Recommended Illuminance for Visually Demanding Tasks within IES Illuminance Categories P through Y Based on Light Source Spectrum

An Optional Method for Adjusting the Recommended Illuminance for Visually Demanding Tasks within IES Illuminance Categories P through Y Based on Light Source Spectrum

$120.00

Member Price: $90.00

ANSI/IES TM-24-20
Document Type: Technical Memorandum (TM)

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 TM-24-20 Category: Tags: ,

Product Description

Approved American National StandardThis document addresses how the spectral power distribution (SPD) of light sources can be incorporated into the IES Illuminance Determination System for visual tasks that are categorized as P through Y within interior lighting applications. It describes how a light source’s SPD affects pupil size, visual acuity, and visual efficiency under interior lighting conditions, and establishes an optional calculation method, Equivalent Visual Efficiency (EVE), for adjusting IES recommenced illuminance targets under limited circumstances when visual tasks require the ability to discern achromatic visual detail to ensure speed and/or accuracy in the performance of the visual task. This Technical Memorandum documents the fundamentals of visual efficiency, defines the EVE calculation method, and addresses practical concerns for implementation.

Page count: 19 pages
Publisher: Illuminating Engineering Society (2020)
SKU: ANSI/IES TM-24-20
ISBN-13: 978-0-87995-391-1

Chapters:

  • 1.0 Introduction and Scope
    2.0 Overview: Concepts and Definitions
    3.0 Basis of the Equivalent Visual Efficiency (EVE) Method
    4.0 Equivalent Visual Efficiency (EVE) Method
    5.0 Implementation Considerations
    6.0 Future Considerations

Citation Format:
Illuminating Engineering Society. ANSI/IES TM-24-20, Technical Memorandum: An Optional Method for Adjusting the Recommended Illuminance for Visually Demanding Tasks within IES Illuminance Categories P through Y Based on Light Source Spectrum. New York: IES; 2020.

CONTENTS

  • 1.0 Introduction and Scope
  • 1.1 Introduction
  • 1.2 Scope
  • 2.0 Overview: Concepts and Definitions
  • 2.1 The Role of Light Source Spectral Power Distribution
  • 2.2 The Spectral Luminous Efficiency Function for Photopic Vision, V(?)
  • 2.3 Pupil Size, Retinal Image Quality, and Visual Acuity
  • 2.4 Visual Efficiency and Visual Effort
  • 2.5 Visually Demanding Tasks
  • 2.6 Visual Performance of Visually Demanding Tasks
  • 2.7 The Aging Visual System
  • 3.0 Basis of the Equivalent Visual Efficiency (EVE) Method
  • 3.1 Overview
  • 3.2 Spectral Sensitivity of the Pupillary Light Reflex
  • 3.3 Adjusting Light Source SPD to Improve Visual Performance
  • 4.0 Equivalent Visual Efficiency (EVE) Method
  • 4.1 Overview
  • 4.2 EVE Calculations
  • 4.3 Example Calculation
  • 4.4 Using the EVE Method with the IES Illuminance Determination System
  • 4.5 Restrictions
  • 5.0 Implementation Considerations
  • 5.1 Acceptability and Visual Comfort
  • 5.2 Color Rendition
  • 5.3 Spatial Brightness
  • 5.4 Glare
  • 5.5 Other Physiological Responses
  • 5.6 Daylighting
  • 6.0 Future Considerations
  • References