---
type: "WebPage"
title: "Measurement of the polydispersity index in the laboratory"
description: "You need to measure the polydispersity index of your polymers Firstly, the polydispersity index is a measure of the heterogeneity of a sample as a function of its size. Polydispersity can be due to the size distribution in a sample..."
resource: "https://filab.fr/en/our-services/our-analysis-services/polymer-materials-analysis-laboratory/measurement-of-the-polydispersity-index-in-the-laboratory/"
tags: ["EN", "pll_62f6115ca2f48", "Thomas GAUTIER"]
timestamp: "2026-01-09T13:50:21Z"
published: "2023-03-21T15:48:33Z"
language: "en"
author: "bwa"
---

# Measurement of the polydispersity index in the laboratory

## You need to measure the polydispersity index of your polymers

Firstly, the polydispersity index is a **measure of the heterogeneity** of a sample as a function of its size. Polydispersity can be due to the size distribution in a sample or to agglomeration or aggregation of the sample during isolation or analysis.

Thus, in the case of a peak, the polydispersity index is 1, in the case of a Gaussian, the index may be greater than 3. The polydispersity index corresponds **to the ratio of the molar mass by weight to the molar mass by number**.

The polydispersity index can be measured with instruments using [dynamic light scattering (DLS)](https://filab.fr/en/our-technical-resources/dynamic-light-scattering-dls-analysis.md).

Therefore, the support of a **laboratory with state-of-the-art analytical equipment including DLS instruments** is necessary to measure the polydispersity index of your polymers.

## FILAB measures the polydispersity index of your polymers in the laboratory

Through our three levels of services: analysis, expertise and R&D support, FILAB assists companies from all sectors in their polydispersity index measurement needs. FILAB provides its customers with the know-how and experience of its team, as well as a5200m² analytical facility equipped with state-of-the-art equipment.

## our services

[Deformation of polymers](https://filab.fr/en/our-services/our-analysis-services/polymer-materials-analysis-laboratory/deformation-of-polymers-in-the-laboratory/)

[Analysis of packaging and polymer packaging](https://filab.fr/en/our-services/our-analysis-services/polymer-materials-analysis-laboratory/analysis-packaging-polymer-packaging.md)

[Analysis of polymeric materials](https://filab.fr/en/our-services/our-analysis-services/polymer-materials-analysis-laboratory/measurement-of-the-polydispersity-index-in-the-laboratory.md)

[Study of cross-linking phenomena on polymeric materials](https://filab.fr/en/our-services/our-analysis-services/polymer-materials-analysis-laboratory/study-of-cross-linking-phenomena-on-polymeric-materials.md)