Last updated on February 28, 2022 by
Spectrometer vs Spectrophotometer: What are the Differences?
Matter absorbs energy, creating an excited state. When matter is made of a certain material, such as metal, it’s easy to see the interaction, because there’s visible evidence, like sparks, created by the electromagnetic waves that form the visible light on the visible spectrum.
Studying interactions between matter and light and actually producing measurements of the interactions are accomplished in different ways, however. Spectroscopy, which is used to study interactions theoretically, cannot produce results. Spectrometry can. These two methods are used together to help researchers better understand ways in which matter interacts, absorbs, and emits light and other radiation.
Spectrometers are the actual instruments used to gather quantitative and qualitative data regarding absorption characteristics and behaviors. However, there are also spectrophotometers, which differ from spectrometers.
To better understand the differences between these two devices, which share quite a few similarities, let’s first review spectroscopy and spectrometry, which, as mentioned, are both used to study the various ways in which matter interacts with (absorbs and emits) light and other radiation.
What Is Spectroscopy?
Spectroscopy is a theoretical approach to studying the absorption and emission characteristics of matter when exposed to electromagnetic radiation, or light. Its definition has expanded to include interactions between electrons, protons, and ions as well.
As a theoretical science, it has played an important role in the development of numerous scientific fields, including physics, chemistry, and even astronomy. Because it’s theoretical, no results are actually obtained via spectroscopy.
There are numerous spectroscopic techniques used in a wide variety of fields. Some of them include:
- Absorption Spectroscopy: With this method of spectroscopy, light is absorbed with respect to the wavelength. The sample molecules are excited to a higher energy state once they absorb the light. The amount of excitation is directly proportional to the wavelength of the light.
- Infrared Spectroscopy: This type of spectroscopy measures the vibrations of the interatomic bonds of a sample. They are measured at different frequencies when the sample is exposed to infrared light. The spectrometers can also be used to measure the number of absorbing molecules.
- X-Ray Spectroscopy: With X-rayspectroscopy, the inner electrons of sample molecules are excited, and when those excited electrons fall into the vacancy generated as a result of energy absorption, an x-rayfluorescenceemission spectrum is produced.
- Ultraviolet Spectroscopy: In this type of spectroscopy, the sample is exposed to ultraviolet (UV) light. Once the samples absorb the light energy, the electrons are excited and the absorbance characteristics of the sample are measured based on this excitation. This type of spectroscopy is often used to investigate chemical bonding of molecules.
- Laser Spectroscopy: Laser spectroscopy uses laser light as a source of radiation. It can be used to measure the interaction of light with sample molecules. This type of spectroscopy has high resolution and high sensitivity.
Spectroscopy is quite essential to all the fields it’s been used in. It not only has provided analysis that has been fundamental to the development of fundamental theories in physics, but it’s also helped scientists better understand electromagnetic force and strong and weak nuclear forces.
What Is Spectrometry?
Spectrometry, on the other hand, deals with actually acquiring a quantitative measurement of a specific spectrum. In other words, it is the application of spectroscopy that creates the results that can be assessed. Thus, you need spectrometry to analyze and interpret spectroscopy.
What Is a Spectrometer?
A spectrometer is any instrument used to measure the variation of a physical characteristic over a spectrum using spectrometry.
These tools are used to collect information about a material based on the amount of infrared, visible, or ultraviolet light it projects. Astronomers use spectrometers to determine the temperature of space objects, determine the speed at which those objects are traveling, and estimate the objects’ weight.
They can also be used to determine the composition of items, including the elemental components. Professionals in the medical field use spectrometers to find toxins and contaminants in the bloodstream, test for doping in sports, and may also find disease markers.
Some other major applications of spectrometers include:
- Monitoring dissolved oxygen content in marine ecosystems
- Space exploration
- Respiratory gas analysis in hospitals
- Characterization of protein
- The study of spectral emission lines of distant galaxies.
What Is a Spectrophotometer?
Spectrophotometry, which differs from spectrometry, measures how much light a chemical substance absorbs. Spectrophotometry is applied using a spectrophotometer.
The exact definition of a spectrophotometer varies depending on the area of science or industry you’re in. However, in all situations, the term “photo” is used to indicate that the spectrometer is used to quantitatively measure light intensity with wavelengths. They can also measure the intensity of electromagnetic radiation at numerous wavelengths.
These tools measure the absorbance of wavelengths of solutions, as well as the transparency or transmittance of solids. They can also measure the reflectance of solutions. Using different calibrations and controls, they can measure the diffusivity of light ranges in the electromagnetic spectrum covering 200 nm to 2500 nm.
Types of Spectrophotometers
There are two basic types of spectrophotometers. The single-beam spectrophotometer measures the relative light intensity before and after the test sample is introduced. The double-beam spectrophotometer compares the intensity of light between a reference light path and the substance being measured. Double beams are not as sensitive to fluctuations in the light source, but single beam options are more compact and have a higher dynamic range.
Other options include:
- Atomic Absorption Spectrophotometer
- Infrared Spectrophotometer
- Laboratory Colorimeter/Digital Colorimeters
The Difference Between a Spectrometer and Spectrophotometer
Part of what makes this confusing for a lot of people is that all spectrophotometers incorporate a spectrometer. It’s also true that other analytical instruments use spectrometers.
The spectrometer is the part of the spectrophotometer that is most responsible for measuring a specific spectrum. Besides the spectrometer, spectrophotometers include a light source along with a means to collect the light that has interacted with the things being tested.
Using a Spectrophotometer
To use a spectrophotometer, turn it on and wait about 5 minutes for it to heat. Load a reference substance and calibrate it. A spectrum will be determined for the sample. Then the wavelengths are measured and analyzed.
From there, the item you want to study is loaded. Light passes through the machine and readings are made based on the colors and information that is reflected.
To use a spectrophotometer, clean the machine to remove all fingerprints and dirt. Add the solution (not water) to the machine. Set to the desired wavelength and insert the blank cuvette, confirming the arrow is aligned.
Calibrate the spectrophotometer by pressing the set 0 button or indicator for the necessary wavelength. Introduce the solution, then calculate its absorbency.
Leasing a Spectrometer or Spectrophotometer With Excedr
When shopping for the right spectrophotometer for your lab, it’s important to consider the applications you’ll be using it for in your lab. Because this lab equipment is pricey, many labs and startups opt to lease their spectrophotometers.
Our leasing program provides you with the ability to procure the exact instrument you want or need at a fraction of the upfront cost compared to purchasing new or refurbished equipment.
Not only does this mean you have more control over your budget, but you also won’t have to worry about the cost of maintenance and equipment upkeep, and you can easily upgrade the equipment once the lease is over.
If you’re interested in leasing a spectrophotometer or spectrometer, let us know.