A Brix refractometer is a device used to measure the sugar content of a liquid. It works by measuring the amount of light that is refracted when a sample of the liquid is placed between two prisms. The refracted light is then measured and the sugar content is determined. The Brix refractometer typically has a scale that ranges from 0-100 Brix, with each number representing the percentage of sugar in the liquid. The Brix refractometer is usually a handheld device with a small viewing window and a scale on the side.