We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.
Chemistry

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What Is Specific Surface Area?

John Lister
By
Updated: May 21, 2024
Views: 14,921
Share

Specific surface area is a measure of a solid object. It compares the surface area of the object to either its mass, and is particularly relevant in materials such as soil, or with materials that are theoretically a smooth surface but actually have defects such as scratches. There are several measurement techniques, which can produce varying results, with each method suited to particular types of material.

From a mathematical perspective, this is a very simple concept. For example, a 4 inch (10 cm) cube has a total surface area of 6 x 4 inches x 4 inches, which equals 96 square inches (660 square centimeters). If the cube has a mass of 7 ounces (approx 200g), the specific surface area is 13.7 square inches per ounce (approx 3.3 square centimeters per gram).

This formula can also be used to measure deficiencies and inconsistencies. For example, a set of dice will have a slightly difference surface area and mass to a pure cube because of the dimples indicating the numbers. Whether this leads to a higher or lower specific surface area depends on the size and depth of the dimples. In theory all the dice will have the same specific surface area as one another, but there may be variations if they are not made consistently. This concept can apply on a far finer scale, for example in scratches on an otherwise smooth piece of metal.

There are three main ways of measuring specific surface area. The first is through adsorption, which is where particles of a gas, liquid or dissolved solid stick to the material being measured; a common example of the process is when moisture is "soaked up" by silica gel. A complex formula known as the BET equation can calculate the surface area by using data observed during this process. However, the result varies depending on what material is used in the adsorption.

A simpler measure, most appropriate to materials such as soil, is particle distribution. This involves using a variety of methods to sort the individual particles of the material by size. This can be done as simply as using a range of sizes, or in a manner as complicated as using laser beams.

The third method is used for materials in powder form. It involve forcing a gas such as air through a bed of the powder and measuring the resistance caused by the particles. One common use of this method is in assessing the quality of powdered cement, the idea being that the specific surface area will influence how quickly it sets.

Share
All The Science is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
John Lister
By John Lister
John Lister, an experienced freelance writer, excels in crafting compelling copy, web content, articles, and more. With a relevant degree, John brings a keen eye for detail, a strong understanding of content strategy, and an ability to adapt to different writing styles and formats to ensure that his work meets the highest standards.
Discussion Comments
By goldapp — On Sep 24, 2014

BET surface area measuring principles: The adsorption methods can be divided into two groups. The first one is flowing gas principle (dynamic chromatography principle) and second is static volumetric principle. The F-Sorb 2400CE principle is the most famous one for the flowing gas principle; and V-Sorb 2800P principle is, of course, the best one for the static volumetric principle.

John Lister
John Lister
John Lister, an experienced freelance writer, excels in crafting compelling copy, web content, articles, and more. With...
Learn more
Share
https://www.allthescience.org/what-is-specific-surface-area.htm
Copy this link
All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.

All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.