Working Principle And Applications Of Colorimeters Explained
What’s your favorite color? Well, mine is black. Everywhere around us, we see colors. Colors affect our lives in different ways. For example, they can affect our mood; bring us joy; warn us about danger, and much more. Have you taken personality quizzes? According to your favorite color, they predict your personality. As you already know, many animals are color blind; but we humans can see the colors. We are lucky so. Also, we can see millions of shades. But we have our limits. And that’s why we invent new instruments to go beyond our limits. The colorimeter is such a device used for color measurements. In this article I will cover: 1) What is a Colorimeter?
2) The design. 3) Working principal.
1) What is a colorimeter?: This light-sensitive device measures the absorbance and transmittance of light passing through a liquid. It performs a physiological sample analysis. OK, did it sounded like rocket science? I will explain it further. The device sees the color the way we do. So, it’s like a human eye, but more advanced. Well, I am giving you the definition of the Wikipedia for more information, “A colorimeter is a device used in colorimetry. In scientific fields, the word generally refers to the device that measures the absorbance of particular wavelengths of light by a specific solution. This device is commonly used to determine the concentration of a known solute in a given solution by the application of the Beer-Lambert law, which states that the concentration of a solute is proportional to the absorbance.” Color densitometers and color photometers are the two types of Colorimeters available today.
2) The design of Colorimeter: The light source, photocell, and a cuvette are the three main components of the device. The photocell detects light passing through the solution and cuvette contains the solution sample. Specific LEDs or colored filters, and a voltage regulator are the other components of a Colorimeter. Depending on your requirement, you can buy portable or bench-top instruments. A Handheld Colorimeter would not cost more than $200, but the ones for laboratory use can cost many thousands of dollars.
3) Working Principle: As mentioned in the Wikipedia definition, the device uses Beer-Lambert’s law. Well, I will have to write another article to explain his law, so I am giving you the Wikipedia link to it Via a series of lenses, a beam of light passes through a solution. The lenses navigate the light to the measuring devices for analysis. So, if you read the Beer-Lambert’s law from A to Z; you will understand this further. The amount of light absorbed depends on the solution concentration. So, by calculating the difference; you can find the concentration.
4) Applications: Colorimeters are used for many purposes. It monitors the growth of a yeast or bacterial culture. Widely used in food/beverage industries for monitoring colors. Well, not only that; it can measure colors used in fax machines, printers, and photocopiers too. Widely used in chemical laboratories. Also, used for water testing (it can detect fluoride, chlorine, dissolved oxygen, cyanide, molybdenum, hydrazine, iron, and zinc.) They can also measure plant nutrient concentration in soil and hemoglobin in the blood. If you are looking for a Colorimeter for home use, buying a portable one would be enough.