Optical Emission Spectroscopy (OES) uses a lot of terms, and occasionally some of them are inaccurately used interchangeably. Though there are certain similarities, spectroscopy and spectrometry are not the same thing.

To better understand the difference between them, it is best to start a basic level.

A Quick Definition of Spectroscopy and Spectrometry

Spectroscopy refers to the study of how radiated energy and matter interact. The energy is absorbed by the matter, creating an excited state. When the matter is a metal, it is easy to see the interaction of energy and matter because the metal will produce visible evidence, usually as sparks. The interaction creates some form of electromagnetic waves (EM), often in the form of visible light, such as sparks.

Spectrometry deals with the measurement of a specific spectrum. There are four primary types of spectrometers:

Mass spectrometry
Neutron triple axis spectrometry
Ion-mobility spectrometry
Rutherford backscattering spectrometry

Each of these types indicates the type of spectrum being measured. Typically, a spectrometer is used to measure a specific spectrometry.

Essentially, spectroscopy is the study of radiated energy and matter to determine their interaction, and it does not create results on its own. Spectrometry is the application of spectroscopy so that there are quantifiable results that can then be assessed.

Application in OES

OES is the focus on understanding the composition of a particular piece of metal, such as a beam, sheet, scrap, or tool. By using a spectrometer, you can determine the level of excitement in the metal’s atoms to determine what kind of metal it is. This is because the different types of metals create different colors, sizes, and appearance for their sparks. The distinction is incredibly difficult to determine by using just the naked human eye as our eyes are not able to see the fine details.

Usually, you would use a small scrap from the metal you have so that you don’t damage large pieces, frames or other structures made of the metal you want to check or identify.

Once you have the sample piece, it is placed in the spectrometer where the reaction is analyzed and the wavelengths of the generated light are used to make the final determination on the metal’s composition. The result is usually a calculated measurement of the elements within the metal.

There are a number of different types of spectrometers. You should take these into consideration if you are thinking about purchasing a spectrometer because each one has its own pros and cons.

Some will give you remarkable speed but their accuracy may not be as high
Other spectrometers that take longer to deliver the results with higher confidence in results.
Each can have different functions and methods of analysis as well.


While there are some people who try to determine a metal through visual estimation, it is not a very reliable means of getting an accurate idea of what kind of metal you have. Using a spectrometer will ensure the job is done correctly with accurate results.