A refractometer is a piece of equipment that can be used to calculate the amount of a specific substance that is present in a liquid solution. It does this by applying the principle of refraction, which explains how light is refracted when it passes through a boundary between two different types of media.
Because of the way in which light is refracted, one of the most common ways that refraction can be demonstrated is by observing how a pencil that is partially submerged in a glass of water appears to be bowed or discontinuous at the boundary line between one medium (air) and the other (water). This is a tried and true method.
Analog handheld refractometers are by far the most common type of this instrument
When viewing the scale on the inside of the meter, the sample is first placed on a cover plate, followed by a prism, and then held up to the light
In most cases, the readout scale is calibrated so that it can be used to determine the concentration of a single substance
The following are some examples of common readouts for refractometers:
A readout on a salinity refractometer will provide the amount of salt present as a percentage.
Brix refractometers are used for quality control in the food and beverage industry. These instruments have a readout that provides the percentage of sucrose present in a sample.
The freezing point and efficiency of ethylene glycol and propylene glycol, two types of coolants that are utilized in a variety of air conditioning systems, can be read off of the readouts of coolant refractometers. Refractometers designed for use with coolant typically also have a readout that can be used with battery fluid to determine the state of the battery.
The readout on clinical refractometers provides the serum albumen and urine specific gravity, which can be used as a test to determine whether or not a urine sample has been tampered with.
With the help of a Handheld Analog Refractometer
1. Before using the refractometer, automatic refractometer must first be calibrated using a standard solution
2. Since the reading will be impacted by changes in temperature, it is best to calibrate the instrument at the temperature that will be present during the test
3. In the event that this cannot be accomplished, correction charts might be used instead
4. Some refractometers have a feature known as automatic temperature correction (ATC), which enables the instrument to automatically adjust its readings in response to changes in the surrounding temperature
After securing the cover plate, a small amount of liquid, usually between two and five drops, should be placed on the prism. This will result in the liquid being distributed evenly across the prism.
A light source should be aimed at the end of the refractometer that contains the prism. Next, the eyepiece should be focused until the scale can be read easily.
Determine the value of the scale by looking at the intersection of the dark and light areas.
Different kinds of refractometers also exist.
In order to use, digital refractometers need to have a drop of the solution being tested placed in a well. A light source, typically an LED light, is used to illuminate that well, and the meter converts the amount of light that passes through it into a refractive index or another unit of measurement, based on how the instrument was programmed.
Abbe refractometers, which are also known as laboratory refractometers, are larger bench-top instruments that offer extremely precise measurements of a substance's refractive index in scientific environments.
