Spectrophotometer

November 1, 2021

The Spectrophotometer is an instrument widely used in laboratories, since it is an analysis device that strengthens the science of spectrophotometry , which is responsible for measuring the intensity of light that is absorbed when passing through a solution.

In that sense, you should know that it has the ability to measure the magnitude of the waves, as well as the relationship they have with the photometric values. This instrument is regularly used to quantify microorganisms and substances in laboratories where chemical research is carried out.

What is a Spectrophotometer?

A spectrophotometer is a device used in laboratories to determine which is the beam of electromagnetic radiation or light and thus identify, qualify and quantify its energy.

In the same way, it allows determining its efficiency, sensitivity, resolution and spectral range. Which will depend on the variabilities of the design and the choice of the optical components it contains.

What is a Spectrophotometer for?

The spectrophotometer basically serves to know what is the concentration of the substances in a solution and thus analyze under the quantitative approach.

It is an instrument used in the laboratory whose main objective is to diagnose, taking into account the properties of light and the interaction with other substances.

How does a Spectrophotometer work?

Its operation is based on the light of the special lamp that it has, which is guided by means of a connector that selects and separates the light from the wavelength, and then passes through a sample.

The intensity of the light that comes out of that sample is captured and compared with the intensity of the light that fell on that sample, with that information the transmittance can be calculated, which will depend on the concentration of the substance.

Basically its operation is to illuminate a sample with white light, and then calculate how much is the amount of light that is reflected through a series of wavelength intervals.

Uses of the Spectrophotometer

Currently, the spectrophotometer can be used in several areas where quantitative analysis is carried out , including biochemistry, physics, biology, materials and chemical engineering, clinical, industrial, and any area that works with chemicals.

In clinic, for example, it is used to examine tissues or blood for a diagnosis. In the laser, optical or printing industry it is used to measure the transmittance or reflectance of solid substances such as polished glass.

Ultimately, this instrument has the ability to determine what substance is present in a sample and how much is its wavelength calculation.

Types of Spectrophotometer

There are different types of spectrophotometers , so that you can make good use of this instrument, I show you below, what are their types:

  • According to its beam of light

This type of spectrophotometer is classified into:

  • Single beam spectrophotometer

Light is transported from the sample to the detector, so a reference is needed to perform the analysis. They are simple and inexpensive.

  • Split beam spectrophotometer

The light is divided into two paths, the one that passes through the monochromator towards the sample and then to the detector, and the one that passes towards the detector that is used to correct for variations in the light emitted by the lamp.

  • Double beam spectrophotometer

The light through two paths to the compartments, each having its own detector. One goes to the sample and the other to the reference.

  • Atomic Absorption Spectrophotometer

This type of spectrophotometer works by taking into account the wavelengths of the electromagnetic radiation spectrum . These are based on the fact that the molecules that absorb the frequencies are part of the characteristics of its structure.

This type is widely used for the analysis of pigments in paintings and manuscripts. In the same way, in the food industry to know the concentration of the compounds of various products.

  • Visible UV Spectrophotometer

Its objective is to measure the light that passes through the sample, and then compare it with its intensity before it passes through a solution or sample. Their ratio is called transmittance, and it is expressed as a percentage.

Knowing all the types of spectrophotometer will make its use much easier, you will also know what each of them is used for, without having problems when identifying it together with other instruments.

Characteristics of a Spectrophotometer

In order to correctly identify and use a laboratory instrument, it is important that you know its physical characteristics, in this way you will know how it works and what its parts are. Here are the main features of the spectrophotometer:

  • Light source

The light source is what illuminates the sample. For the measurement to be reliable, it must meet certain conditions, such as stability, spectral energy distribution and addressability.

Spectrophotometers can have a variety of light sources, such as tungsten, xenon arc, and deuterium lamps, which are used in atomic laboratories.

  • Monochromator

It has the ability to completely isolate the radiation of the desired wavelength, thus achieving a monochromatic light. You can see that it has two openings, one for the outlet and the other for the inlet, as well as a part called collimators and dispersion elements.

  • Collimator

It is nothing more than the lens that is responsible for moving the light that enters with a certain length towards the prism. It separates the wavelengths, ensuring that it is redirected to the outlet openings.

  • Sample compartment

It is the spectrophotometer component where the interaction takes place, that is, where the sample to be worked on is placed.

  • Detector

It is in charge of knowing the radiation to be analyzed and knowing what kind of response it faces, whether it is photons or heat.

  • Recorder

It is the one that converts the physical elements to equal numbers that are analyzed.

  • Photosetectors

The photodetectors of a spectrophotometer are those that receive the signal simultaneously with the visible spectrum, in order to reduce the measurement time and minimize the other parts of the apparatus.

Once you know the characteristics of any work tool, you will feel more comfortable when using it, therefore, it is important to do some research before performing any procedure that involves a work tool.

Importance of a Spectrophotometer

The spectrophotometer is essential to carry out investigations regarding the determination of the concentration of substances , thus allowing to achieve quantitative analysis.

This instrument strengthens the technique of spectrophotometry, it measures the amount of energy that a chemical system can absorb depending on the wavelength that radiation transmits.

This theory of light is what proposes the idea that a beam of light is a flow of energy called photons and light of some wavelength is associated with them, each of which has a certain amount of energy.

In this sense, the spectrophotometer in a laboratory strengthens the information that a sample may contain on the nature of the substance. Likewise, it is the one that indicates the amount of substance that is in the sample and the one that is going to be investigated.

Dr. Loony Davis5
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Born and raised in Brussels in an English family, I have always lived in a multicultural environment. After several work experiences in marketing and communication, I came to Smart Water Magazine, which I describe as the most exciting challenge of my career.
I am a person with great restlessness and curiosity to learn, discover what I do not know, as well as reinvent myself daily, someone who is curious about life and wants to know. I enjoy sharing knowledge.
This is my personal project but I also collaborate in other blogs, it is the case, the most important web on water currently exists in the US, if you are interested you can read my articles here.

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