--- title: What is Viscosity, and Why is Measuring Viscosity Important? description: Learn about t viscosity, Newtonian, and Non-Newtonian fluids, how viscosity is measured, and what materials or products can use viscosity testing. --- [![CSC Scientific Company, Inc.](https://www.cscscientific.com/hs-fs/file-1239671252-jpg/images/csc-logo-1.jpg "CSC Scientific Company, Inc.")](https://www.cscscientific.com/?hsLang=en-us) # Viscosity Testing Testing the Flow Properties of Liquid Products ### Learn About Viscosity #### **On the CSC Blog:** - [Can You Define Viscosity Without Feeling Thick?](https://www.cscscientific.com/csc-cientific-blog/bid/95124/Can-You-Define-Viscosity-Without-Feeling-Thick?hsLang=en-us)  - [How Can I Measure Viscosity?](https://www.cscscientific.com/csc-cientific-blog/bid/98427/How-Can-I-Measure-Viscosity?hsLang=en-us)  - [How Does Surface Tension Relate to Viscosity?](https://www.cscscientific.com/csc-cientific-blog/bid/52996/How-Does-Surface-Tension-Relate-to-Viscosity?hsLang=en-us) - [Is Consistency Viscosity? Not Really!](https://www.cscscientific.com/csc-cientific-blog/bid/25536/Is-Consistency-Viscosity-Not-really?hsLang=en-us) - [How Are Consistency, Surface Tension and Viscosity Different?](https://www.cscscientific.com/csc-cientific-blog/bid/102345/How-Are-Consistency-Surface-Tension-and-Viscosity-Different?hsLang=en-us) - [Viscosity Basics: For Those of Us Who Aren't Scientists](https://www.cscscientific.com/csc-cientific-blog/bid/101944/Viscosity-Basics-For-Those-of-Us-Who-Aren-t-Scientists?hsLang=en-us) #### Definitions: [![Consistency vs. Viscosity](http://cdn1.hubspot.com/hubshot/13/09/12/170e9450-e177-41be-8987-ce253df8010f.png)](http://cta-service-cms2.hubspot.com/cs/c/?&cta_guid=9401e3b0-8820-4fbc-8642-f01c8d694ffc&placement_guid=f4f26539-2eff-417f-b580-5a65c1a060a0&portal_id=75757&redirect_url=8TkXqpDfq2v49wRgc2Wh0V836OBQR7u2J3yTiISy5JzXFUxlMPKRJipcK2FmkOhqoYxug4SPzxVqdReB%2BBnU3KXlaZ21Av05eAO93WNsRAwOKOgLEPsXuaLEp8Bi4VgZ&iv=6KyYuqY1n28%3D&hsutk=64364039c2a905ef5ce4a6d39bce1c97&utm_referrer=http%3A%2F%2Fwww.cscscientific.com%2Fviscosity%2F&canon=) [![Newtonian vs. Non-Newtonian Fluids](https://www.cscscientific.com/hs-fs/hub/75757/file-338539089.png)](http://cta-service-cms2.hubspot.com/cs/c/?&cta_guid=643b7a99-2b6f-4fe2-86bb-b011da21b0a5&placement_guid=0cd313bb-6e5f-4c7d-b06f-561c8a91b15b&portal_id=75757&redirect_url=StRIGBESK0ZPxyUVK2oKDnjMsmPGPYFsyhJ2G2TU9QfVLpFslWVruR67MhAUzwUttqtjgnX4TSqWouro4wN0Xlh2eU42fgjawTQ%2BM1nMKzTi77cDKaOHS4i5euCXra4scy4GEfAcjVY%3D&iv=QdpKZZySmsw%3D&hsutk=64364039c2a905ef5ce4a6d39bce1c97&utm_referrer=http%3A%2F%2Fwww.cscscientific.com%2Fviscosity%2F&canon=) # Why Should You Measure Viscosity? ![Ketchup flowing out of bottle](https://www.cscscientific.com/hs-fs/hubfs/Ketchup%20flowing%20out%20of%20bottle.jpg?width=300&name=Ketchup%20flowing%20out%20of%20bottle.jpg) Gathering viscosity data on a material gives manufacturers the ability to predict how the material will behave in the real world. For example: if toothpaste does not have the correct viscosity, it can either be too difficult to pump out from the tube, or pump out too much. Knowing the viscosity of a material also affects how the production and transportation processes are designed.  CSC Scientific sells [**Rotational Viscometers**](https://www.cscscientific.com/viscosity/viscometers?hsLang=en-us) that can adapt to the testing method required for measuring the viscosity of Newtonian and Non-Newtonian fluids. We also sell the new [**EMS-1000 Viscometer**](https://www.cscscientific.com/ems-1000-viscometer?hsLang=en-us), a high-tech electromagnetic spinning viscometer for tricky applications like adhesives, blood, and expensive perfumes.  # What is Viscosity? **Viscosity is the measure of a substance's resistance to motion under an applied force. ** The formula for measuring viscosity is fairly simple: *viscosity = shear stress / shear rate* The result is typically expressed in **centipoise** (cP), which is the equivalent of 1 mPa s (millipascal second).  **Shear stress **is the force per unit area required to move one layer of fluid in relation to another. **Shear rate** is the measure of the change in speed at which intermediate layers move with respect to one another. ## **Newtonian vs. Non-Newtonian Fluids** Isaac Newton, the man to discover this formula, thought that, at a given temperature and shear stress, the viscosity of a fluid would remain constant regardless of changes to the shear rate.  He was only partly right. A few fluids, such as water and honey, do behave this way. We call these fluids **Newtonian fluids**. Most fluids, however, have viscosities that fluctuate depending on the shear rate. These are called **Non-Newtonian fluids**. There are five types of non-Newtonian fluids: thixotropic, rheopectic, pseudoplastic, dilatant, and plastic. Different considerations are required when measuring each of these fluid types. # Who Does Viscosity Testing? ### **The following are examples of how viscosity measurements are used:** #### Food Viscosity measurements are [used in the food industry](https://www.cscscientific.com/csc-cientific-blog/why-test-for-viscosity-in-food?hsLang=en-us) to maximize production efficiency and cost effectiveness. It affects the rate at which a product travels through a pipe, how long it takes to set or dry, and the time it takes to dispense the fluid into packaging. The production process has to be designed with the viscosity of the product in mind, making sure that pipes are angled to optimize flow, or that dispensers provide the right amount of force to induce flow, but not so much that the packaging will overfill. Viscosity is also a characteristic of the [texture of food](https://www.cscscientific.com/csc-cientific-blog/food-texture-analysis?hsLang=en-us). The product’s viscosity must be measured and monitored during production to ensure that each batch is consistent and will go through the production process efficiently.  #### Adhesives To choose the right viscosity for an adhesive, consider how the adhesive must flow, or not flow, on a part after the adhesive is applied. Low-viscosity adhesives will flow more readily than high-viscosity ones, so if you want an adhesive to stay exactly where you put it after dispensing – rather than spread out – a high-viscosity adhesive is ideal.  #### Other Industries *Petroleum:* Viscosity measurements project the effectiveness of lubricating oil and determines design elements of pipelines. *Concrete:* Viscosity determines the self-leveling and pumping behavior of a mix. *Cosmetics:* Viscosity should be considered when designing the feel and flow of cosmetic products. CSC Scientific Company, Inc 2799-C Merrilee Drive Fairfax VA, 22031 800-621-4778 703-280-5142 (fax) csc@cscscientific.com [![credit cards](https://cdn2.hubspot.net/hub/75757/images//creditcard.gif)](http://www.cscscientific.us) No part of this page or any other page in this site may be copied or reproduced in any way. 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