A refractometer is an optical instrument used to measure the refractive index of a transparent liquid or solid. This refractive index is a physical quantity that characterizes the ability of that substance to bend light. 

ATAGO PAL-1 (0-53%) Electronic Brix Refractometer

Refractometers are used to measure the following parameters:

• Concentration: The most common purpose of a refractometer is to determine the concentration of solutions. When a substance dissolves in water (or other solvent), the refractive index of the solution changes proportionally to the concentration of the solute.

• Brix level: In the food and beverage industry, refractometers are widely used to measure Brix (%), which is the percentage by mass of sugar in a solution. This helps control the quality of fruits, juices, wines, and honey. Acidity can also be measured.

• Salinity: A refractometer measures the salinity (salt concentration) of seawater, aquarium water, or other solutions, usually expressed in parts per thousand (ppt) or percentage.

HANNA HI96822 Seawater Salinity Refractometer

• Specific gravity: In some applications, such as measuring antifreeze in automobiles, refractometers can provide scales directly related to the specific gravity of the solution.
• Purity and substance identification: By comparing the measured refractive index to standard values, refractometers can help check the purity of a substance or aid in the identification of different types of oils, fats, or chemicals.

A&D AD-4771 Brix sweetness measuring device 0.00~55.00%

Refractometers can be classified based on several different criteria, primarily according to method of reading results, design dimensions and specialized applications. 

1. Classification based on method of reading results

This is the most common classification, dividing refractometers into two main types:

• Optical (analog/mechanical) refractometer: Operating on the principle of simple light refraction, the user observes the result through the eyepiece and reads the value on the integrated scale.
  • Advantages: Low cost, high durability, no batteries or power source required.
  • Disadvantages: Accuracy depends on the reader, and errors can easily occur due to viewing angle or ambient lighting.
• Digital (electronic) refractometer: Integrating sensors and an LCD display, it automatically measures and provides results for refractive index or related scales (Brix, salinity, etc.).
  • Advantages: High accuracy, eliminates reader error, easy to use, and can store data.
  • Disadvantages: Higher cost, requires a power source (battery), may require more frequent calibration. 

2. Classification by size and portability

• Portable/Handheld Refractometer: Compact and lightweight, they are designed for field use, in production processes, or outdoors. Both optical and digital types are available in handheld versions. They are highly portable but generally have lower accuracy than desktop versions.
• Benchtop/Laboratory Refractometer: Larger, stationary refractometers are commonly used in laboratories. They offer higher accuracy and stability, with many advanced features such as automatic temperature control, the ability to measure diverse samples (liquids, solids, and transparent), and complex data management. The Abbe refractometer is a classic benchtop refractometer. 

3. Classification by specific application (Measurement scale)

Although many refractometers can measure general refractive index, they are often designed with occupational-specific scales:

• Brix meter (Refractometer for measuring sweetness): Used in the food industry to measure sugar content in fruits, beverages, and honey.
• Salinity refractometer: Used to measure salinity in seawater, aquariums, or processing industries.
• Refractometer for measuring alcohol content: Used to determine the alcohol content in alcoholic beverages.
• Medical/Veterinary Refractometer: Used to measure urine specific gravity or serum protein concentration.
• Industrial refractometer: Used to test the concentration of antifreeze, lubricants, or detergents in automotive and chemical industries.

You can contact Semiki Instrumentation Co., Ltd directly to purchase genuine refractometers.

When contacting us, please provide information about the type of refractometer you need to purchase (e.g., Brix refractometer, salinity refractometer, alcohol refractometer, or digital/handheld type) so that Semiki consultants can help you choose the most suitable product.

Contact Semiki directly: You can find Semiki's contact information (via website or phone number) to request a quote and specific advice.

Website: You can find out more details and send a consultation request via Semiki.com.

Business email: [email protected]

Phone number (Hotline): +84 979 761 016.