The so-called refractometers are used to measure the refractive index of solid and liquid transparent materials. By using these devices, the amount of solids contained in any liquid material is also determined. With the refractometer measuring device, the refractive index of a substance of known purity is measured and the value obtained is compared with the standards. In this way, other physical properties and refractive index of an unrecognized substance are combined to define what the substance is.

In the food sector, refractometric methods are used in the analysis of food products such as oil and fruit juice. It is also used frequently in the pharmaceutical, chemical and sugar industries. Refractometric methods are generally used safely by laboratories for ease and accuracy.

Refractometric methods are mainly based on the refraction of light as it passes from one medium to the other in different intensity refractive environments. By using this feature, refractometer device is used to determine the moisture content in various foods. For example, when a refractometer is used to determine the amount of water in the honey, the obtained values ​​are evaluated according to TS 13365 standard (TS 13365 Honey - Determination of water content - Refractometric method).

Refractometric methods and moisture determination measurements are also performed in the authorized laboratories within the scope of physical analyzes. During these studies, the standards issued by national and international organizations are based. At the same time, globally accepted test methods and test criteria are complied with. In this way, impartial and reliable results are obtained.

Moisture measurement by refractometric methods is applied not only to liquid foods but also to foods that need to be low in moisture, such as cereals and cereals, legumes and spices. Foodstuffs are generally water and dry matter. When the water is removed, dry matter remains.