---
title: How is refractive index different from absorbance which is conventionally measured with a spectrophotometer?
description: The spectrophotometer can measure the attenuation (absorbance or optical density) at a wavelength or as the full spectrum is scanned. Absorbance or optical density is relevant when substances are colo
---

[Skip to content](https://knowledge.cphnano.com/en/pages/how-is-refractive-index-different-from-absorbance-which-is-conventionally-measured-with-a-spectrophotometer#main-content)

[![](https://knowledge.cphnano.com/hubfs/Logos/AFDE_20250411_Copenhagen_Nanosystems_Logo_Tagline_Short.svg)](https://cphnano.com/)

Open main navigation

Close main navigation

 SpectroKnowledge™ Library - Independent resource on spectroscopy

- There are no suggestions because the search field is empty.

1. [SpectroKnowledge™](https://knowledge.cphnano.com/en/pages)
2. [NanoCuvette™ S](https://knowledge.cphnano.com/en/pages/nanocuvette-s)
3. [Frequently Asked Questions (FAQ)](https://knowledge.cphnano.com/en/pages/nanocuvette-s#frequently-asked-questions-faq)

May 18, 2022

# How is refractive index different from absorbance which is conventionally measured with a spectrophotometer?

The spectrophotometer can measure the attenuation (absorbance or optical density) at a wavelength or as the full spectrum is scanned. Absorbance or optical density is relevant when substances are colored or absorbing light. The refractive index is a physical property of a substance at a specific wavelength. Our online software calculates the refractive index internally at 589 nm. 

- [SpectroShell™](https://knowledge.cphnano.com/en/pages/spectroshell)
- [NanoCuvette™ One](https://knowledge.cphnano.com/en/pages/nanocuvette-one#main-content)
  
  
  
  
  
    - [Webinars](https://knowledge.cphnano.com/en/pages/nanocuvette-one#webinars)
    - [Frequently Asked Questions (FAQ)](https://knowledge.cphnano.com/en/pages/nanocuvette-one#frequently-asked-questions-faq)
    - [Peer-reviewed articles](https://knowledge.cphnano.com/en/pages/nanocuvette-one#peer-reviewed-articles)
    - [White papers](https://knowledge.cphnano.com/en/pages/nanocuvette-one#white-papers)
    - [Get started](https://knowledge.cphnano.com/en/pages/nanocuvette-one#get-started)
    - [Solutions](https://knowledge.cphnano.com/en/pages/nanocuvette-one#solutions)
    - [Basics](https://knowledge.cphnano.com/en/pages/nanocuvette-one#basics)
    - [Troubleshooting](https://knowledge.cphnano.com/en/pages/nanocuvette-one#troubleshooting)
    - [Certificates](https://knowledge.cphnano.com/en/pages/nanocuvette-one#certificates)
    - [Teaching material](https://knowledge.cphnano.com/en/pages/nanocuvette-one#teaching-material)
    - [Application notes](https://knowledge.cphnano.com/en/pages/nanocuvette-one#application-notes)
- [SpectroLink™](https://knowledge.cphnano.com/en/pages/spectrolink#main-content)
  
  
  
  
  
    - [User Guides](https://knowledge.cphnano.com/en/pages/spectrolink#user-guides)
    - [Troubleshooting](https://knowledge.cphnano.com/en/pages/spectrolink#troubleshooting)
    - [Introduction](https://knowledge.cphnano.com/en/pages/spectrolink#introduction)
    - [Frequently asked questions (FAQ) and Essential Information](https://knowledge.cphnano.com/en/pages/spectrolink#frequently-asked-questions-faq-and-essential-information)
    - [Security and Privacy](https://knowledge.cphnano.com/en/pages/spectrolink#security-and-privacy)
- [SpectroWorks™](https://knowledge.cphnano.com/en/pages/spectroworks#main-content)
  
  
  
  
  
    - [Account and cancellation](https://knowledge.cphnano.com/en/pages/spectroworks#account-and-cancellation)
    - [Security, Privacy and the Cloud](https://knowledge.cphnano.com/en/pages/spectroworks#security-privacy-and-the-cloud)
    - [Introduction](https://knowledge.cphnano.com/en/pages/spectroworks#introduction)
    - [Troubleshooting](https://knowledge.cphnano.com/en/pages/spectroworks#troubleshooting)
    - [User Guides](https://knowledge.cphnano.com/en/pages/spectroworks#user-guides)
    - [Frequently Asked Questions (FAQ) and Essential Information](https://knowledge.cphnano.com/en/pages/spectroworks#frequently-asked-questions-faq-and-essential-information)
    - [Data analysis powered by Python](https://knowledge.cphnano.com/en/pages/spectroworks#data-analysis-powered-by-python)
- [Spectrophotometry fundamentals](https://knowledge.cphnano.com/en/pages/spectrophotometry-fundamentals#main-content)
  
  
  
  
  
    - [Jenway Descriptions](https://knowledge.cphnano.com/en/pages/spectrophotometry-fundamentals#jenway-descriptions)
    - [Light](https://knowledge.cphnano.com/en/pages/spectrophotometry-fundamentals#light)
    - [Calculations](https://knowledge.cphnano.com/en/pages/spectrophotometry-fundamentals#calculations)
    - [PerkinElmer Descriptions](https://knowledge.cphnano.com/en/pages/spectrophotometry-fundamentals#perkinelmer-descriptions)
    - [Instrument components](https://knowledge.cphnano.com/en/pages/spectrophotometry-fundamentals#instrument-components)
    - [VWR Descriptions](https://knowledge.cphnano.com/en/pages/spectrophotometry-fundamentals#vwr-descriptions)
    - [Ocean Optics Descriptions](https://knowledge.cphnano.com/en/pages/spectrophotometry-fundamentals#ocean-optics-descriptions)
    - [Applications](https://knowledge.cphnano.com/en/pages/spectrophotometry-fundamentals#applications)
    - [ACTTR Descriptions](https://knowledge.cphnano.com/en/pages/spectrophotometry-fundamentals#acttr-descriptions)
    - [Agilent Descriptions](https://knowledge.cphnano.com/en/pages/spectrophotometry-fundamentals#agilent-descriptions)
    - [Shimadzu Descriptions](https://knowledge.cphnano.com/en/pages/spectrophotometry-fundamentals#shimadzu-descriptions)
    - [Hitachi Descriptions](https://knowledge.cphnano.com/en/pages/spectrophotometry-fundamentals#hitachi-descriptions)
- [NanoCuvette™ S](https://knowledge.cphnano.com/en/pages/nanocuvette-s#main-content)
  
  
  
  
  
    - [Webinar](https://knowledge.cphnano.com/en/pages/nanocuvette-s#webinar)
    - [Certificates](https://knowledge.cphnano.com/en/pages/nanocuvette-s#certificates)
    - [Get started](https://knowledge.cphnano.com/en/pages/nanocuvette-s#get-started)
    - [Troubleshooting](https://knowledge.cphnano.com/en/pages/nanocuvette-s#troubleshooting)
    - [Application Notes](https://knowledge.cphnano.com/en/pages/nanocuvette-s#application-notes)
    - [Frequently Asked Questions (FAQ)](https://knowledge.cphnano.com/en/pages/nanocuvette-s#frequently-asked-questions-faq)
    - [Validation reports](https://knowledge.cphnano.com/en/pages/nanocuvette-s#validation-reports)

[![AFDE_20250411_Copenhagen_Nanosystems_Logo_Tagline_Short](https://knowledge.cphnano.com/hubfs/Logos/AFDE_20250411_Copenhagen_Nanosystems_Logo_Tagline_Short.svg "AFDE_20250411_Copenhagen_Nanosystems_Logo_Tagline_Short")](https://cphnano.com)

SpectroKnowledge™ - Independent resource on UV-Vis spectroscopy by Copenhagen Nanosystems.

<https://www.facebook.com/> [mailto:email@email.com](mailto:email@email.com)

Copyright © 2025, Copenhagen Nanosystems A/S