---
title: Calculating Carbon Type by D2140 (refractivity intercept)
description: Calculating carbon type D2140, refractivity intercept.
---

[Skip to content](https://knowledge.rudolphresearch.com/calculating-carbon-type-by-d2140-refractivity-intercept#main-content)

English

Show submenu for translations

![RRA\_Logo\_For\_email.png\]](https://knowledge.rudolphresearch.com/hs-fs/hubfs/RRA_Logo_For_email.png?height=50&name=RRA_Logo_For_email.png)

Open main navigation

Close main navigation

- English
  
  Show submenu for translations
- [Go to rudolphresearch.com](https://rudolphresearch.com/)

[Go to rudolphresearch.com](https://rudolphresearch.com/)

 Hello. How can we help you?

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

1. [Ask Professor Rudy](https://knowledge.rudolphresearch.com/?hsLang=en)
2. [FAQ](https://knowledge.rudolphresearch.com/faq?hsLang=en)

# Calculating Carbon Type by D2140 (refractivity intercept)

## When calculating Carbon Type by D2140 do you need to calculate refractivity intercept using refractive index and density.

Yes, when calculating Carbon Type by D2140 you need to calculate refractivity intercept using refractive index and density. 

- [Product Information](https://knowledge.rudolphresearch.com/product-information?hsLang=en#main-content)

    - [Autopol® Polarimeters](https://knowledge.rudolphresearch.com/product-information?hsLang=en#autopol-polarimeters)
    - [Density Meters](https://knowledge.rudolphresearch.com/product-information?hsLang=en#density-meters)
    - [Refractometers](https://knowledge.rudolphresearch.com/product-information?hsLang=en#refractometers)
- [Troubleshooting](https://knowledge.rudolphresearch.com/troubleshooting?hsLang=en#main-content)

    - [Polarimeter](https://knowledge.rudolphresearch.com/troubleshooting?hsLang=en#polarimeter)
    - [AutoFlex](https://knowledge.rudolphresearch.com/troubleshooting?hsLang=en#autoflex)
    - [Density Meter](https://knowledge.rudolphresearch.com/troubleshooting?hsLang=en#density-meter)
    - [Refractometer](https://knowledge.rudolphresearch.com/troubleshooting?hsLang=en#refractometer)
    - [AlcoTest](https://knowledge.rudolphresearch.com/troubleshooting?hsLang=en#alcotest)
    - [Data Backup/Audit Trail/ Historical Data](https://knowledge.rudolphresearch.com/troubleshooting?hsLang=en#data-backup-audit-trail-historical-data)
    - [Pinter](https://knowledge.rudolphresearch.com/troubleshooting?hsLang=en#pinter)
    - [Troubleshooting - Boot Up Issue](https://knowledge.rudolphresearch.com/troubleshooting?hsLang=en#troubleshooting-boot-up-issue)
- [How To](https://knowledge.rudolphresearch.com/how-to?hsLang=en#main-content)

    - [Density Meter](https://knowledge.rudolphresearch.com/how-to?hsLang=en#density-meter)
    - [Polarimeter](https://knowledge.rudolphresearch.com/how-to?hsLang=en#polarimeter)
    - [AlcoTest](https://knowledge.rudolphresearch.com/how-to?hsLang=en#alcotest)
    - [Automation](https://knowledge.rudolphresearch.com/how-to?hsLang=en#automation)
    - [Refractometer](https://knowledge.rudolphresearch.com/how-to?hsLang=en#refractometer)
    - [21CFR11](https://knowledge.rudolphresearch.com/how-to?hsLang=en#21cfr11)
    - [Minimum PC Specifications](https://knowledge.rudolphresearch.com/how-to?hsLang=en#minimum-pc-specifications)
    - [VeriLinkRx](https://knowledge.rudolphresearch.com/how-to?hsLang=en#verilinkrx)
- [FAQ](https://knowledge.rudolphresearch.com/faq?hsLang=en#main-content)

    - [Printers](https://knowledge.rudolphresearch.com/faq?hsLang=en#printers)
    - [Warranty Coverage](https://knowledge.rudolphresearch.com/faq?hsLang=en#warranty-coverage)
    - [VeriLink Rx](https://knowledge.rudolphresearch.com/faq?hsLang=en#verilink-rx)
    - [Audit Trail](https://knowledge.rudolphresearch.com/faq?hsLang=en#audit-trail)
    - [Ports & Connections](https://knowledge.rudolphresearch.com/faq?hsLang=en#ports-connections)
    - [Software/Upgrades](https://knowledge.rudolphresearch.com/faq?hsLang=en#software-upgrades)
    - [Sample Cell](https://knowledge.rudolphresearch.com/faq?hsLang=en#sample-cell)
    - [AlcoTest-RI](https://knowledge.rudolphresearch.com/faq?hsLang=en#alcotest-ri)
    - [Quartz Control Plate (QCP)](https://knowledge.rudolphresearch.com/faq?hsLang=en#quartz-control-plate-qcp)
    - [Octapol](https://knowledge.rudolphresearch.com/faq?hsLang=en#octapol)
    - [Density](https://knowledge.rudolphresearch.com/faq?hsLang=en#density)

[![RRA logo](https://knowledge.rudolphresearch.com/hs-fs/hubfs/RRA%20logo.webp?width=300&height=137&name=RRA%20logo.webp "RRA logo")](http://rudolphresearch.com)

Welcome to the Rudolph Research Knowledge Base

Copyright © 2026, https://rudolphresearch.com/